**Item category:** 1,2-Diazidoethane

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 1,2-Diazidoethane Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,2-Diazidoethane — Postal shipping restrictions by item category


**Item category:** 1,2-Dibromobutan-3-one

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2648, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 1,2-Dibromobutan-3-one 6.1 UN2648 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,2-Dibromobutan-3-one — Postal shipping restrictions by item category


**Item category:** 1,2-Dichloro-1,1,2,2- Tetrafluoroethane or Refrigerant gas R 114

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 2.2, UN1958, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B

> 1,2-Dichloro-1,1,2,2- Tetrafluoroethane or Refrigerant gas R 114 2.2 UN1958 n/a 2B 2B

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,2-Dichloro-1,1,2,2- Tetrafluoroethane or Refrigerant gas R 114 — Postal shipping restrictions by item category


**Item category:** 1,2-Dichloroethylene

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN1150, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 1,2-Dichloroethylene 3 UN1150 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,2-Dichloroethylene — Postal shipping restrictions by item category


**Item category:** 1,2-Dichloropropane

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN1279, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 1,2-Dichloropropane 3 UN1279 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,2-Dichloropropane — Postal shipping restrictions by item category


**Item category:** 1,2-Dimethoxyethane

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2252, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 1,2-Dimethoxyethane 3 UN2252 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,2-Dimethoxyethane — Postal shipping restrictions by item category


**Item category:** 1,2-Dinitroethane

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 1,2-Dinitroethane Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,2-Dinitroethane — Postal shipping restrictions by item category


**Item category:** 1,2-Epoxy-3-ethoxypropane

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2752, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A

> 1,2-Epoxy-3-ethoxypropane 3 UN2752 III Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,2-Epoxy-3-ethoxypropane — Postal shipping restrictions by item category


**Item category:** 1,2-Propylenediamine

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN2258, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 1,2-Propylenediamine 8 UN2258 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,2-Propylenediamine — Postal shipping restrictions by item category


**Item category:** 1,3,5-Trimethyl-2,4,6-trinitrobenzene

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 1,3,5-Trimethyl-2,4,6-trinitrobenzene Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,3,5-Trimethyl-2,4,6-trinitrobenzene — Postal shipping restrictions by item category


**Item category:** 1,3,5-Trimethylbenzene

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN2325, packing group III; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 1,3,5-Trimethylbenzene 3 UN2325 III Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,3,5-Trimethylbenzene — Postal shipping restrictions by item category


**Item category:** 1,3,5-Trinitronaphthalene

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> Prohibited 1,3,5-Trinitronaphthalene

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,3,5-Trinitronaphthalene — Postal shipping restrictions by item category


**Item category:** 1,3-Diazopropane

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 1,3-Diazopropane Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,3-Diazopropane — Postal shipping restrictions by item category


**Item category:** 1,3-Dichloroacetone

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2649, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 1,3-Dichloroacetone 6.1 UN2649 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,3-Dichloroacetone — Postal shipping restrictions by item category


**Item category:** 1,3-Dichloropropanol2

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2750, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 1,3-Dichloropropanol2 6.1 UN2750 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,3-Dichloropropanol2 — Postal shipping restrictions by item category


**Item category:** 1,3-Dimethylbutylamine

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN2379, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 1,3-Dimethylbutylamine 3 UN2379 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,3-Dimethylbutylamine — Postal shipping restrictions by item category


**Item category:** 1,3-Dinitro-4,5-dinitrosobenzene

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 1,3-Dinitro-4,5-dinitrosobenzene Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,3-Dinitro-4,5-dinitrosobenzene — Postal shipping restrictions by item category


**Item category:** 1,3-Dinitro-5,5-dimethyl hydantoin

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 1,3-Dinitro-5,5-dimethyl hydantoin Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,3-Dinitro-5,5-dimethyl hydantoin — Postal shipping restrictions by item category


**Item category:** 1,4-Butynediol

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2716, packing group III; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 1,4-Butynediol 6.1 UN2716 III Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,4-Butynediol — Postal shipping restrictions by item category


**Item category:** 1,4-Dinitro-1,1,4,4- tetramethylolbutanetetranitrate (dry)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 1,4-Dinitro-1,1,4,4- tetramethylolbutanetetranitrate (dry) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,4-Dinitro-1,1,4,4- tetramethylolbutanetetranitrate (dry) — Postal shipping restrictions by item category


**Item category:** 1,5,9-Cyclododecatriene

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2518, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> 1,5,9-Cyclododecatriene 6.1 UN2518 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,5,9-Cyclododecatriene — Postal shipping restrictions by item category


**Item category:** 1,7-Octadiene-3,5-diyne1,8- dimethoxy- 9-octadecynoic acid

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 1,7-Octadiene-3,5-diyne1,8- dimethoxy- 9-octadecynoic acid Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,7-Octadiene-3,5-diyne1,8- dimethoxy- 9-octadecynoic acid — Postal shipping restrictions by item category


**Item category:** 1,8-Dihydroxy-2,4,5,7- tetranitroanthraquinone (chrysamminic acid)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 1,8-Dihydroxy-2,4,5,7- tetranitroanthraquinone (chrysamminic acid) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,8-Dihydroxy-2,4,5,7- tetranitroanthraquinone (chrysamminic acid) — Postal shipping restrictions by item category


**Item category:** 1,9-Dinitroxy pentamethylene2,4,6,8tetramine (dry)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 1,9-Dinitroxy pentamethylene2,4,6,8tetramine (dry) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1,9-Dinitroxy pentamethylene2,4,6,8tetramine (dry) — Postal shipping restrictions by item category


**Item category:** 1-Bromo-3-chloropropane

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2688, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> 1-Bromo-3-chloropropane 6.1 UN2688 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Bromo-3-chloropropane — Postal shipping restrictions by item category


**Item category:** 1-Bromo-3-methylbutane

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2341, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A

> 1-Bromo-3-methylbutane 3 UN2341 III Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Bromo-3-methylbutane — Postal shipping restrictions by item category


**Item category:** 1-Bromo-3-nitrobenzene (unstable at 56° C)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 1-Bromo-3-nitrobenzene (unstable at 56° C) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Bromo-3-nitrobenzene (unstable at 56° C) — Postal shipping restrictions by item category


**Item category:** 1-Bromobutane

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN1126, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 1-Bromobutane 3 UN1126 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Bromobutane — Postal shipping restrictions by item category


**Item category:** 1-Chloro-1,1-difluoroethane or Refrigerant gas R 142b

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 2.1, UN2517, packing group n/a; domestic mail air: Prohibited; domestic mail surface: 2A

> 1-Chloro-1,1-difluoroethane or Refrigerant gas R 142b 2.1 UN2517 n/a Prohibited 2A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Chloro-1,1-difluoroethane or Refrigerant gas R 142b — Postal shipping restrictions by item category


**Item category:** 1-Chloro-1,2,2,2-tetrafluoroethane or Refrigerant gas R 124

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 2.2, UN1021, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B

> 1-Chloro-1,2,2,2-tetrafluoroethane or Refrigerant gas R 124 2.2 UN1021 n/a 2B 2B

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Chloro-1,2,2,2-tetrafluoroethane or Refrigerant gas R 124 — Postal shipping restrictions by item category


**Item category:** 1-Chloro-2,2,2-trifluoroethane or Refrigerant gas R 133a

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 2.2, UN1983, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B

> 1-Chloro-2,2,2-trifluoroethane or Refrigerant gas R 133a 2.2 UN1983 n/a 2B 2B

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Chloro-2,2,2-trifluoroethane or Refrigerant gas R 133a — Postal shipping restrictions by item category


**Item category:** 1-Chloropropane

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN1278, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 1-Chloropropane 3 UN1278 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Chloropropane — Postal shipping restrictions by item category


**Item category:** 1-Ethylpiperidine

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN2386, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 1-Ethylpiperidine 3 UN2386 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Ethylpiperidine — Postal shipping restrictions by item category


**Item category:** 1-Hexene

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2370, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 1-Hexene 3 UN2370 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Hexene — Postal shipping restrictions by item category


**Item category:** 1-Hydroxybenzotriazole, anhydrous, dry or wetted with less than 20 percent water, by mass

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 1.3C, UN0508, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 1-Hydroxybenzotriazole, anhydrous, dry or wetted with less than 20 percent water, by mass 1.3C UN0508 n/a Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Hydroxybenzotriazole, anhydrous, dry or wetted with less than 20 percent water, by mass — Postal shipping restrictions by item category


**Item category:** 1-Hydroxybenzotriazole, monohydrate

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 4.1, UN3474, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 1-Hydroxybenzotriazole, monohydrate 4.1 UN3474 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Hydroxybenzotriazole, monohydrate — Postal shipping restrictions by item category


**Item category:** 1-Methoxy-2-propanol

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN3092, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A

> 1-Methoxy-2-propanol 3 UN3092 III Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Methoxy-2-propanol — Postal shipping restrictions by item category


**Item category:** 1-Methylpiperidine

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN2399, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 1-Methylpiperidine 3 UN2399 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Methylpiperidine — Postal shipping restrictions by item category


**Item category:** 1-Nitrohydantoin

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 1-Nitrohydantoin Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Nitrohydantoin — Postal shipping restrictions by item category


**Item category:** 1-Pentene (n-amylene)

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN1108, packing group I; domestic mail air: Prohibited; domestic mail surface: 3A

> 1-Pentene (n-amylene) 3 UN1108 I Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Pentene (n-amylene) — Postal shipping restrictions by item category


**Item category:** 1-Pentol

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN2705, packing group II; domestic mail air: 8A; domestic mail surface: 8A

> 1-Pentol 8 UN2705 II 8A 8A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1-Pentol — Postal shipping restrictions by item category


**Item category:** 10 percent but not more than 85 percent acid by mass

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN3412, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 10 percent but not more than 85 percent acid by mass 8 UN3412 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

10 percent but not more than 85 percent acid by mass — Postal shipping restrictions by item category


**Item category:** 173.21

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 173.21 Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

173.21 — Postal shipping restrictions by item category


**Item category:** 173.247(h)(4)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 9, UN3258, packing group III; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 173.247(h)(4) 9 UN3258 III Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

173.247(h)(4) — Postal shipping restrictions by item category


**Item category:** 1H-Tetrazole

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 1.1D, UN0504, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 1H-Tetrazole 1.1D UN0504 n/a Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

1H-Tetrazole — Postal shipping restrictions by item category


**Item category:** [2,2,1]hepta-2,5-diene, stabilized Dicyclohexylamine

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN2565, packing group III; domestic mail air: 8A; domestic mail surface: 8A

> [2,2,1]hepta-2,5-diene, stabilized Dicyclohexylamine 8 UN2565 III 8A 8A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

[2,2,1]hepta-2,5-diene, stabilized Dicyclohexylamine — Postal shipping restrictions by item category


**Item category:** 2,2’,3’,4,4’,6- Hexanitrodiphenylamine

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,2’,3’,4,4’,6- Hexanitrodiphenylamine Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,2’,3’,4,4’,6- Hexanitrodiphenylamine — Postal shipping restrictions by item category


**Item category:** 2,2’,4,4’,6,6’-Hexanitro-3,3’- dihydroxyazobenzene (dry)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,2’,4,4’,6,6’-Hexanitro-3,3’- dihydroxyazobenzene (dry) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,2’,4,4’,6,6’-Hexanitro-3,3’- dihydroxyazobenzene (dry) — Postal shipping restrictions by item category


**Item category:** 2-(2-Aminoethoxy) ethanol

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN3055, packing group III; domestic mail air: 8A; domestic mail surface: 8A

> 2-(2-Aminoethoxy) ethanol 8 UN3055 III 8A 8A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-(2-Aminoethoxy) ethanol — Postal shipping restrictions by item category


**Item category:** 2,2-Di-(4,4-di-tert- butylperoxycyclohexyl) propane, with more than 42 percent with inert solid

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,2-Di-(4,4-di-tert- butylperoxycyclohexyl) propane, with more than 42 percent with inert solid Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,2-Di-(4,4-di-tert- butylperoxycyclohexyl) propane, with more than 42 percent with inert solid — Postal shipping restrictions by item category


**Item category:** 2,2-Di-(tert-butylperoxy) butane, with more than 55 percent in solution

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,2-Di-(tert-butylperoxy) butane, with more than 55 percent in solution Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,2-Di-(tert-butylperoxy) butane, with more than 55 percent in solution — Postal shipping restrictions by item category


**Item category:** 2,2’-Dichlorodiethyl ether

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN1916, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 2,2’-Dichlorodiethyl ether 6.1 UN1916 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,2’-Dichlorodiethyl ether — Postal shipping restrictions by item category


**Item category:** 2,2-Dimethylpropane

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 2.1, UN2044, packing group n/a; domestic mail air: Prohibited; domestic mail surface: 2A

> 2,2-Dimethylpropane 2.1 UN2044 n/a Prohibited 2A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,2-Dimethylpropane — Postal shipping restrictions by item category


**Item category:** 2,2-Dinitrostilbene

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,2-Dinitrostilbene Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,2-Dinitrostilbene — Postal shipping restrictions by item category


**Item category:** 2,3’,4,4’,6,6’-Hexanitrodiphenylether

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,3’,4,4’,6,6’-Hexanitrodiphenylether Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,3’,4,4’,6,6’-Hexanitrodiphenylether — Postal shipping restrictions by item category


**Item category:** 2,3,4,6-Tetranitrophenol

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,3,4,6-Tetranitrophenol Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,3,4,6-Tetranitrophenol — Postal shipping restrictions by item category


**Item category:** 2,3,4,6-Tetranitrophenyl methyl nitramine

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,3,4,6-Tetranitrophenyl methyl nitramine Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,3,4,6-Tetranitrophenyl methyl nitramine — Postal shipping restrictions by item category


**Item category:** 2,3,4,6-Tetranitrophenylnitramine

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,3,4,6-Tetranitrophenylnitramine Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,3,4,6-Tetranitrophenylnitramine — Postal shipping restrictions by item category


**Item category:** 2,3,5,6-Tetranitroso-1,4- dinitrobenzene

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,3,5,6-Tetranitroso-1,4- dinitrobenzene Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,3,5,6-Tetranitroso-1,4- dinitrobenzene — Postal shipping restrictions by item category


**Item category:** 2,3,5,6-Tetranitroso nitrobenzene (dry)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,3,5,6-Tetranitroso nitrobenzene (dry) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,3,5,6-Tetranitroso nitrobenzene (dry) — Postal shipping restrictions by item category


**Item category:** 2,3-Dihydropyran

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2376, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 2,3-Dihydropyran 3 UN2376 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,3-Dihydropyran — Postal shipping restrictions by item category


**Item category:** 2,3-Dimethylbutane

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2457, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 2,3-Dimethylbutane 3 UN2457 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,3-Dimethylbutane — Postal shipping restrictions by item category


**Item category:** 2,4,6-Trinitro-1,3,5-triazido benzene (dry)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,4,6-Trinitro-1,3,5-triazido benzene (dry) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,4,6-Trinitro-1,3,5-triazido benzene (dry) — Postal shipping restrictions by item category


**Item category:** 2,4,6-Trinitro-1,3-diazobenzene

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,4,6-Trinitro-1,3-diazobenzene Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,4,6-Trinitro-1,3-diazobenzene — Postal shipping restrictions by item category


**Item category:** 2,4,6-Trinitrophenyl guanidine (dry)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,4,6-Trinitrophenyl guanidine (dry) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,4,6-Trinitrophenyl guanidine (dry) — Postal shipping restrictions by item category


**Item category:** 2,4,6-Trinitrophenyl nitramine

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,4,6-Trinitrophenyl nitramine Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,4,6-Trinitrophenyl nitramine — Postal shipping restrictions by item category


**Item category:** 2,4,6-Trinitrophenyl trimethylol methyl nitramine trinitrate (dry)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,4,6-Trinitrophenyl trimethylol methyl nitramine trinitrate (dry) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,4,6-Trinitrophenyl trimethylol methyl nitramine trinitrate (dry) — Postal shipping restrictions by item category


**Item category:** 2,4,6-Trinitroso-3-methyl nitraminoanisole

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,4,6-Trinitroso-3-methyl nitraminoanisole Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,4,6-Trinitroso-3-methyl nitraminoanisole — Postal shipping restrictions by item category


**Item category:** 2,4-Dinitro-1,3,5-trimethylbenzene

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,4-Dinitro-1,3,5-trimethylbenzene Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,4-Dinitro-1,3,5-trimethylbenzene — Postal shipping restrictions by item category


**Item category:** 2,4-Toluylenediamine, solid or 2,4- Toluenediamine, solid

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN1709, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> 2,4-Toluylenediamine, solid or 2,4- Toluenediamine, solid 6.1 UN1709 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,4-Toluylenediamine, solid or 2,4- Toluenediamine, solid — Postal shipping restrictions by item category


**Item category:** 2,4-Toluylenediamine, solution or 2,4-Toluenediamine, solution

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN3418, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> 2,4-Toluylenediamine, solution or 2,4-Toluenediamine, solution 6.1 UN3418 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,4-Toluylenediamine, solution or 2,4-Toluenediamine, solution — Postal shipping restrictions by item category


**Item category:** 2,-4Dinitroresorcinol (heavy metal salts of) (dry)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,-4Dinitroresorcinol (heavy metal salts of) (dry) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,-4Dinitroresorcinol (heavy metal salts of) (dry) — Postal shipping restrictions by item category


**Item category:** 2,5-Dimethyl-2,5-dihydroperoxy hexane, with more than 82 percent with water

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2,5-Dimethyl-2,5-dihydroperoxy hexane, with more than 82 percent with water Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2,5-Dimethyl-2,5-dihydroperoxy hexane, with more than 82 percent with water — Postal shipping restrictions by item category


**Item category:** 2-Amino-4,6-Dinitrophenol, wetted with not less than 20 percent water by mass

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 4.1, UN3317, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 2-Amino-4,6-Dinitrophenol, wetted with not less than 20 percent water by mass 4.1 UN3317 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Amino-4,6-Dinitrophenol, wetted with not less than 20 percent water by mass — Postal shipping restrictions by item category


**Item category:** 2-Amino-4-chlorophenol

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2673, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 2-Amino-4-chlorophenol 6.1 UN2673 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Amino-4-chlorophenol — Postal shipping restrictions by item category


**Item category:** 2-Amino-5-diethylaminopentane

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2946, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> 2-Amino-5-diethylaminopentane 6.1 UN2946 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Amino-5-diethylaminopentane — Postal shipping restrictions by item category


**Item category:** 2-Bromo-2-nitropropane-1,3-diol

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 4.1, UN3241, packing group III; domestic mail air: Prohibited; domestic mail surface: 4A

> 2-Bromo-2-nitropropane-1,3-diol 4.1 UN3241 III Prohibited 4A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Bromo-2-nitropropane-1,3-diol — Postal shipping restrictions by item category


**Item category:** 2-Bromobutane

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2339, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 2-Bromobutane 3 UN2339 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Bromobutane — Postal shipping restrictions by item category


**Item category:** 2-Bromoethyl ethyl ether

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2340, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 2-Bromoethyl ethyl ether 3 UN2340 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Bromoethyl ethyl ether — Postal shipping restrictions by item category


**Item category:** 2-Bromopentane

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2343, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 2-Bromopentane 3 UN2343 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Bromopentane — Postal shipping restrictions by item category


**Item category:** 2-Chloroethanal

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2232, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 2-Chloroethanal 6.1 UN2232 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Chloroethanal — Postal shipping restrictions by item category


**Item category:** 2-Chloropropane

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2356, packing group I; domestic mail air: Prohibited; domestic mail surface: 3A

> 2-Chloropropane 3 UN2356 I Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Chloropropane — Postal shipping restrictions by item category


**Item category:** 2-Chloropropene

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2456, packing group I; domestic mail air: Prohibited; domestic mail surface: 3A

> 2-Chloropropene 3 UN2456 I Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Chloropropene — Postal shipping restrictions by item category


**Item category:** 2-Chloropropionic acid

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN2511, packing group III; domestic mail air: 8A; domestic mail surface: 8A

> 2-Chloropropionic acid 8 UN2511 III 8A 8A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Chloropropionic acid — Postal shipping restrictions by item category


**Item category:** 2-Chloropyridine

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2822, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 2-Chloropyridine 6.1 UN2822 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Chloropyridine — Postal shipping restrictions by item category


**Item category:** 2-Diethylaminoethanol

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN2686, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 2-Diethylaminoethanol 8 UN2686 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Diethylaminoethanol — Postal shipping restrictions by item category


**Item category:** 2-Dimethylaminoacetonitrile

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN2378, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 2-Dimethylaminoacetonitrile 3 UN2378 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Dimethylaminoacetonitrile — Postal shipping restrictions by item category


**Item category:** 2-Dimethylaminoethanol

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN2051, packing group II; domestic mail air: 8A; domestic mail surface: 8A

> 2-Dimethylaminoethanol 8 UN2051 II 8A 8A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Dimethylaminoethanol — Postal shipping restrictions by item category


**Item category:** 2-Dimethylaminoethyl acrylate

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN3302, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 2-Dimethylaminoethyl acrylate 6.1 UN3302 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Dimethylaminoethyl acrylate — Postal shipping restrictions by item category


**Item category:** 2-Dimethylaminoethyl methacrylate

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2522, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 2-Dimethylaminoethyl methacrylate 6.1 UN2522 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Dimethylaminoethyl methacrylate — Postal shipping restrictions by item category


**Item category:** 2-Ethylaniline

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2273, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> 2-Ethylaniline 6.1 UN2273 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Ethylaniline — Postal shipping restrictions by item category


**Item category:** 2-Ethylbutanol

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2275, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A

> 2-Ethylbutanol 3 UN2275 III Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Ethylbutanol — Postal shipping restrictions by item category


**Item category:** 2-Ethylbutyl acetate

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN1177, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A

> 2-Ethylbutyl acetate 3 UN1177 III Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Ethylbutyl acetate — Postal shipping restrictions by item category


**Item category:** 2-Ethylbutyraldehyde

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN1178, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 2-Ethylbutyraldehyde 3 UN1178 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Ethylbutyraldehyde — Postal shipping restrictions by item category


**Item category:** 2-Ethylhexylamine

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2276, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A

> 2-Ethylhexylamine 3 UN2276 III Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Ethylhexylamine — Postal shipping restrictions by item category


**Item category:** 2-Iodobutane

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2390, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 2-Iodobutane 3 UN2390 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Iodobutane — Postal shipping restrictions by item category


**Item category:** 2-Methyl-1-butene

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN2459, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 2-Methyl-1-butene 3 UN2459 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Methyl-1-butene — Postal shipping restrictions by item category


**Item category:** 2-Methyl-2-butene

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN2460, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 2-Methyl-2-butene 3 UN2460 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Methyl-2-butene — Postal shipping restrictions by item category


**Item category:** 2-Methyl-2-heptanethiol

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN3023, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 2-Methyl-2-heptanethiol 6.1 UN3023 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Methyl-2-heptanethiol — Postal shipping restrictions by item category


**Item category:** 2-Methyl-5-ethylpyridine

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2300, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> 2-Methyl-5-ethylpyridine 6.1 UN2300 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Methyl-5-ethylpyridine — Postal shipping restrictions by item category


**Item category:** 2-Methylfuran

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2301, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 2-Methylfuran 3 UN2301 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Methylfuran — Postal shipping restrictions by item category


**Item category:** 2-Methylpentan-2-ol

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2560, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A

> 2-Methylpentan-2-ol 3 UN2560 III Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Methylpentan-2-ol — Postal shipping restrictions by item category


**Item category:** 2-Nitro-2-methylpropanol nitrate

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 2-Nitro-2-methylpropanol nitrate Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Nitro-2-methylpropanol nitrate — Postal shipping restrictions by item category


**Item category:** 2 percent tear gas substances, by mass

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, NA1693, packing group I, II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 2 percent tear gas substances, by mass 6.1 NA1693 I, II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2 percent tear gas substances, by mass — Postal shipping restrictions by item category


**Item category:** 2-Trifluoromethylaniline

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2942, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> 2-Trifluoromethylaniline 6.1 UN2942 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

2-Trifluoromethylaniline — Postal shipping restrictions by item category


**Item category:** 20 percent hydrogen cyanide

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN1613, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 20 percent hydrogen cyanide 6.1 UN1613 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

20 percent hydrogen cyanide — Postal shipping restrictions by item category


**Item category:** 3,3-Diethoxypropene

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2374, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 3,3-Diethoxypropene 3 UN2374 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

3,3-Diethoxypropene — Postal shipping restrictions by item category


**Item category:** 3,3’-Iminodipropylamine

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN2269, packing group III; domestic mail air: 8A; domestic mail surface: 8A

> 3,3’-Iminodipropylamine 8 UN2269 III 8A 8A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

3,3’-Iminodipropylamine — Postal shipping restrictions by item category


**Item category:** 3,5-Dichloro-2,4,6-trifluoropyridine

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, NA9264, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 3,5-Dichloro-2,4,6-trifluoropyridine 6.1 NA9264 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

3,5-Dichloro-2,4,6-trifluoropyridine — Postal shipping restrictions by item category


**Item category:** 3,5-Dinitrosalicylic acid (lead salt) (dry)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 3,5-Dinitrosalicylic acid (lead salt) (dry) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

3,5-Dinitrosalicylic acid (lead salt) (dry) — Postal shipping restrictions by item category


**Item category:** 3-Azido-1,2-Propylene glycol dinitrate

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 3-Azido-1,2-Propylene glycol dinitrate Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

3-Azido-1,2-Propylene glycol dinitrate — Postal shipping restrictions by item category


**Item category:** 3-Bromopropyne

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2345, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 3-Bromopropyne 3 UN2345 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

3-Bromopropyne — Postal shipping restrictions by item category


**Item category:** 3-Chloro-4-methylphenyl isocyanate, liquid

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2236, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 3-Chloro-4-methylphenyl isocyanate, liquid 6.1 UN2236 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

3-Chloro-4-methylphenyl isocyanate, liquid — Postal shipping restrictions by item category


**Item category:** 3-Chloro-4-methylphenyl isocyanate, solid

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN3428, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 3-Chloro-4-methylphenyl isocyanate, solid 6.1 UN3428 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

3-Chloro-4-methylphenyl isocyanate, solid — Postal shipping restrictions by item category


**Item category:** 3-Chloropropanol-1

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2849, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> 3-Chloropropanol-1 6.1 UN2849 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

3-Chloropropanol-1 — Postal shipping restrictions by item category


**Item category:** 3-Diethylamino-propylamine

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2684, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A

> 3-Diethylamino-propylamine 3 UN2684 III Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

3-Diethylamino-propylamine — Postal shipping restrictions by item category


**Item category:** 3-Methyl-1-butene

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN2561, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 3-Methyl-1-butene 3 UN2561 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

3-Methyl-1-butene — Postal shipping restrictions by item category


**Item category:** 3-Methylbutan-2-one

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2397, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> 3-Methylbutan-2-one 3 UN2397 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

3-Methylbutan-2-one — Postal shipping restrictions by item category


**Item category:** 3-Nitro-4-chlorobenzotrifluoride

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2307, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 3-Nitro-4-chlorobenzotrifluoride 6.1 UN2307 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

3-Nitro-4-chlorobenzotrifluoride — Postal shipping restrictions by item category


**Item category:** 3-Trifluoromethylaniline

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2948, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 3-Trifluoromethylaniline 6.1 UN2948 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

3-Trifluoromethylaniline — Postal shipping restrictions by item category


**Item category:** 4,4’-Diaminodiphenyl methane

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2651, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> 4,4’-Diaminodiphenyl methane 6.1 UN2651 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

4,4’-Diaminodiphenyl methane — Postal shipping restrictions by item category


**Item category:** 4,6-Dinitroresorcinol (heavy metal salts of) (dry)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 4,6-Dinitroresorcinol (heavy metal salts of) (dry) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

4,6-Dinitroresorcinol (heavy metal salts of) (dry) — Postal shipping restrictions by item category


**Item category:** 4-Bromo-1,2-dinitrobenzene (unstable at 59° C)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 4-Bromo-1,2-dinitrobenzene (unstable at 59° C) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

4-Bromo-1,2-dinitrobenzene (unstable at 59° C) — Postal shipping restrictions by item category


**Item category:** 4-Bromo-1,2-dinitrobenzene

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 4-Bromo-1,2-dinitrobenzene Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

4-Bromo-1,2-dinitrobenzene — Postal shipping restrictions by item category


**Item category:** 4-Chloro-o-toluidine hydrochloride, solid

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN1579, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> 4-Chloro-o-toluidine hydrochloride, solid 6.1 UN1579 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

4-Chloro-o-toluidine hydrochloride, solid — Postal shipping restrictions by item category


**Item category:** 4-Chloro-o-toluidine hydrochloride, solution

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN3410, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> 4-Chloro-o-toluidine hydrochloride, solution 6.1 UN3410 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

4-Chloro-o-toluidine hydrochloride, solution — Postal shipping restrictions by item category


**Item category:** 4-Methoxy-4-methylpentan-2-one

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2293, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A

> 4-Methoxy-4-methylpentan-2-one 3 UN2293 III Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

4-Methoxy-4-methylpentan-2-one — Postal shipping restrictions by item category


**Item category:** 4-Methylmorpholine or n- methylmorpholine

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN2535, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 4-Methylmorpholine or n- methylmorpholine 3 UN2535 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

4-Methylmorpholine or n- methylmorpholine — Postal shipping restrictions by item category


**Item category:** 4-Nitrophenylhydrazine, with not less than 30 percent water, by mass

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 4.1, UN3376, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 4-Nitrophenylhydrazine, with not less than 30 percent water, by mass 4.1 UN3376 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

4-Nitrophenylhydrazine, with not less than 30 percent water, by mass — Postal shipping restrictions by item category


**Item category:** 4-Thiapentanal

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2785, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> 4-Thiapentanal 6.1 UN2785 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

4-Thiapentanal — Postal shipping restrictions by item category


**Item category:** 5-Azido-1-hydroxy tetrazole

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 5-Azido-1-hydroxy tetrazole Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

5-Azido-1-hydroxy tetrazole — Postal shipping restrictions by item category


**Item category:** 5-Mercaptotetrazol-1-acetic acid

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 1.4C, UN0448, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 5-Mercaptotetrazol-1-acetic acid 1.4C UN0448 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

5-Mercaptotetrazol-1-acetic acid — Postal shipping restrictions by item category


**Item category:** 5-Methylhexan-2-one

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2302, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A

> 5-Methylhexan-2-one 3 UN2302 III Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

5-Methylhexan-2-one — Postal shipping restrictions by item category


**Item category:** 5-Nitrobenzotriazol

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 1.1D, UN0385, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 5-Nitrobenzotriazol 1.1D UN0385 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

5-Nitrobenzotriazol — Postal shipping restrictions by item category


**Item category:** 5-tert-Butyl-2,4,6-trinitro-m-xylene or Musk xylene

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 4.1, UN2956, packing group III; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 5-tert-Butyl-2,4,6-trinitro-m-xylene or Musk xylene 4.1 UN2956 III Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

5-tert-Butyl-2,4,6-trinitro-m-xylene or Musk xylene — Postal shipping restrictions by item category


**Item category:** 6-Nitro-4-diazotoluene-3-sulfonic acid (dry)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> 6-Nitro-4-diazotoluene-3-sulfonic acid (dry) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

6-Nitro-4-diazotoluene-3-sulfonic acid (dry) — Postal shipping restrictions by item category


**Item category:** 64 percent hydrazine, by mass

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN2029, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 64 percent hydrazine, by mass 8 UN2029 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

64 percent hydrazine, by mass — Postal shipping restrictions by item category


**Item category:** 9-Phosphabicyclononanes or Cyclooctadiene phosphines

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 4.2, UN2940, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> 9-Phosphabicyclononanes or Cyclooctadiene phosphines 4.2 UN2940 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

9-Phosphabicyclononanes or Cyclooctadiene phosphines — Postal shipping restrictions by item category


**Item category:** a,a’-Di-(nitroxy) methylether

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> a,a’-Di-(nitroxy) methylether Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

a,a’-Di-(nitroxy) methylether — Postal shipping restrictions by item category


**Item category:** a-Methylglucoside tetranitrate

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> a-Methylglucoside tetranitrate Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

a-Methylglucoside tetranitrate — Postal shipping restrictions by item category


**Item category:** a-Methylglycerol trinitrate

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> a-Methylglycerol trinitrate Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

a-Methylglycerol trinitrate — Postal shipping restrictions by item category


**Item category:** Acetal

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN1088, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> Acetal 3 UN1088 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetal — Postal shipping restrictions by item category


**Item category:** Acetaldehyde ammonia

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 9, UN1841, packing group III; domestic mail air: Prohibited; domestic mail surface: 9C

> Acetaldehyde ammonia 9 UN1841 III Prohibited 9C

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetaldehyde ammonia — Postal shipping restrictions by item category


**Item category:** Acetaldehyde oxime

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2332, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A

> Acetaldehyde oxime 3 UN2332 III Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetaldehyde oxime — Postal shipping restrictions by item category


**Item category:** Acetaldehyde

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN1089, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> Acetaldehyde 3 UN1089 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetaldehyde — Postal shipping restrictions by item category


**Item category:** Acetic acid, glacial or Acetic acid solution, with more than 80 percent acid, by mass

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN2789, packing group II; domestic mail air: 8A; domestic mail surface: 8A

> Acetic acid, glacial or Acetic acid solution, with more than 80 percent acid, by mass 8 UN2789 II 8A 8A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetic acid, glacial or Acetic acid solution, with more than 80 percent acid, by mass — Postal shipping restrictions by item category


**Item category:** Acetic acid solution, not less than 50 percent but not more than 80 percent acid, by mass

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN2790, packing group II; domestic mail air: 8A; domestic mail surface: 8A

> Acetic acid solution, not less than 50 percent but not more than 80 percent acid, by mass 8 UN2790 II 8A 8A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetic acid solution, not less than 50 percent but not more than 80 percent acid, by mass — Postal shipping restrictions by item category


**Item category:** Acetic acid solution, with more than 10 percent and less than 50 percent acid, by mass

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN2790, packing group III; domestic mail air: 8A; domestic mail surface: 8A

> Acetic acid solution, with more than 10 percent and less than 50 percent acid, by mass 8 UN2790 III 8A 8A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetic acid solution, with more than 10 percent and less than 50 percent acid, by mass — Postal shipping restrictions by item category


**Item category:** Acetic acid (UN2790)

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail via air or surface transportation

**Conditions:** Mailable if meets Limited Quantity requirements, contains less than 80% acid, and does not exceed 1 pint; Packaging Instruction 8A must be followed

> Acetic Acid (UN2790): May be mailable if they meet Limited Quantity requirements for air or surface material, contains less than 80 percent acid, and does not exceed 1 pint.

Source: <https://pe.usps.com/text/pub52/pub52c3_027.htm>

Acetic acid (UN2790) — Postal shipping restrictions by item category


**Item category:** Acetic anhydride

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN1715, packing group II; domestic mail air: 8A; domestic mail surface: 8A

> Acetic anhydride 8 UN1715 II 8A 8A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetic anhydride — Postal shipping restrictions by item category


**Item category:** Acetone cyanohydrin, stabilized

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN1541, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> Acetone cyanohydrin, stabilized 6.1 UN1541 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetone cyanohydrin, stabilized — Postal shipping restrictions by item category


**Item category:** Acetone oils

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN1091, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> Acetone oils 3 UN1091 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetone oils — Postal shipping restrictions by item category


**Item category:** Acetone (UN1090), Benzene (UN1114), Hexane(s) (UN1208)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** all mail

**Conditions:** Nonmailable unless diluted with less flammable or nonflammable materials sufficient to raise flashpoint to 20 F or higher

> Acetone (UN1090) normally has a flashpoint of 0° F, Benzene (UN1114) normally has a flashpoint of 12° F, and Hexane(s) (UN1208) normally have flashpoints in the vicinity of -15° F. All are nonmailable unless diluted

Source: <https://pe.usps.com/text/pub52/pub52c3_022.htm>

Acetone (UN1090), Benzene (UN1114), Hexane(s) (UN1208) — Postal shipping restrictions by item category

carrier, conditions, item_category, restriction_type, scope


**Item category:** Acetone

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN1090, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> Acetone 3 UN1090 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetone — Postal shipping restrictions by item category


**Item category:** Acetonitrile

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN1648, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A

> Acetonitrile 3 UN1648 II Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetonitrile — Postal shipping restrictions by item category


**Item category:** Acetyl acetone peroxide with more than 9 percent by mass active oxygen

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> Acetyl acetone peroxide with more than 9 percent by mass active oxygen Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetyl acetone peroxide with more than 9 percent by mass active oxygen — Postal shipping restrictions by item category


**Item category:** Acetyl benzoyl peroxide, solid, or with more than 40 percent in solution

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> Acetyl benzoyl peroxide, solid, or with more than 40 percent in solution Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetyl benzoyl peroxide, solid, or with more than 40 percent in solution — Postal shipping restrictions by item category


**Item category:** Acetyl bromide

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN1716, packing group II; domestic mail air: 8A; domestic mail surface: 8A

> Acetyl bromide 8 UN1716 II 8A 8A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetyl bromide — Postal shipping restrictions by item category


**Item category:** Acetyl chloride

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN1717, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> Acetyl chloride 3 UN1717 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetyl chloride — Postal shipping restrictions by item category


**Item category:** Acetyl cyclohexanesulfonyl peroxide, with more than 82 percent wetted with less than 12 percent water

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> Acetyl cyclohexanesulfonyl peroxide, with more than 82 percent wetted with less than 12 percent water Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetyl cyclohexanesulfonyl peroxide, with more than 82 percent wetted with less than 12 percent water — Postal shipping restrictions by item category


**Item category:** Acetyl iodide

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN1898, packing group II; domestic mail air: 8A; domestic mail surface: 8A

> Acetyl iodide 8 UN1898 II 8A 8A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetyl iodide — Postal shipping restrictions by item category


**Item category:** Acetyl methyl carbinol

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2621, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A

> Acetyl methyl carbinol 3 UN2621 III Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetyl methyl carbinol — Postal shipping restrictions by item category


**Item category:** Acetyl peroxide, solid, or with more than 25 percent in solution

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> Acetyl peroxide, solid, or with more than 25 percent in solution Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetyl peroxide, solid, or with more than 25 percent in solution — Postal shipping restrictions by item category


**Item category:** Acetylene, dissolved

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 2.1, UN1001, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited

> Acetylene, dissolved 2.1 UN1001 n/a Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetylene, dissolved — Postal shipping restrictions by item category


**Item category:** Acetylene (liquified)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> Acetylene (liquified) Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetylene (liquified) — Postal shipping restrictions by item category


**Item category:** Acetylene silver nitrate

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> Acetylene silver nitrate Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetylene silver nitrate — Postal shipping restrictions by item category


**Item category:** Acetylene, solvent free

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

> Acetylene, solvent free Forbidden Prohibited Prohibited Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acetylene, solvent free — Postal shipping restrictions by item category


**Item category:** Acridine

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2713, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> Acridine 6.1 UN2713 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acridine — Postal shipping restrictions by item category


**Item category:** Acrolein dimer, stabilized

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN2607, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A

> Acrolein dimer, stabilized 3 UN2607 III Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acrolein dimer, stabilized — Postal shipping restrictions by item category


**Item category:** Acrolein, stabilized

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN1092, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> Acrolein, stabilized 6.1 UN1092 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acrolein, stabilized — Postal shipping restrictions by item category


**Item category:** Acrylamide, solid

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2074, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> Acrylamide, solid 6.1 UN2074 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acrylamide, solid — Postal shipping restrictions by item category


**Item category:** Acrylamide, solution

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN3426, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> Acrylamide, solution 6.1 UN3426 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acrylamide, solution — Postal shipping restrictions by item category


**Item category:** Acrylic acid, stabilized

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 8, UN2218, packing group II; domestic mail air: 8A; domestic mail surface: 8A

> Acrylic acid, stabilized 8 UN2218 II 8A 8A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acrylic acid, stabilized — Postal shipping restrictions by item category


**Item category:** Acrylonitrile, stabilized

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN1093, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> Acrylonitrile, stabilized 3 UN1093 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Acrylonitrile, stabilized — Postal shipping restrictions by item category


**Item category:** Adhesives and cements (UN1133)

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail via surface transportation only

**Conditions:** Mailable only if qualifies as Limited Quantity surface material and meets conditions; Packaging Instruction 3A or 3B as applicable

> 52/pub52apxc_001.htm#ep999476> Appendix C must be followed. Adhesives and Cements (UN1133): A flammable liquid with an approximate flashpoint of 73° F (23° C) is mailable only if it qualifies as a Limited Quantity surface material and meets the conditions in 343.21 or 343.22 as applicable. Packaging Instruction 3A or 3B in <https://pe.usps.com/text/p

Source: <https://pe.usps.com/text/pub52/pub52c3_022.htm>

Adhesives and cements (UN1133) — Postal shipping restrictions by item category


**Item category:** Adhesives, containing a flammable liquid

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 3, UN1133, packing group I, II, III; domestic mail air: Prohibited; domestic mail surface: 3A

> Adhesives, containing a flammable liquid 3 UN1133 I, II, III Prohibited 3A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Adhesives, containing a flammable liquid — Postal shipping restrictions by item category


**Item category:** Adiponitrile

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 6.1, UN2205, packing group III; domestic mail air: 6A; domestic mail surface: 6A

> Adiponitrile 6.1 UN2205 III 6A 6A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Adiponitrile — Postal shipping restrictions by item category


**Item category:** Aerosol deodorant

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic US

**Conditions:** Classified as flammable aerosol. Requires hazmat declaration and rigid outer packaging. $50 noncompliance fee if undeclared, effective July 12, 2026.

> Aerosol deodorant | Flammable aerosol | UN1950

Source: <https://selleressentials.com/usps-hazmat-noncompliance-fee-2026/>

Aerosol deodorant — Postal shipping restrictions by item category


**Item category:** Aerosol paint products (flammable compressed gas)

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail via surface transportation only

**Conditions:** Acceptable via surface transportation only if qualifies as Limited Quantity ground material and meets quantity limitations and applicable packaging requirements

> Aerosol Paint Products: Aerosol paint products that are defined as flammable compressed gases are acceptable in the domestic mail via surface transportation only if they can qualify as a Limited Quantity ground material

Source: <https://pe.usps.com/text/pub52/pub52c3_021.htm>

Aerosol paint products (flammable compressed gas) — Postal shipping restrictions by item category


**Item category:** Aerosol sprays

**Carrier:** USPS

**Restriction type:** hazmat declaration required

**Scope:** online marketplace seller shipments (Poshmark)

**Conditions:** Subject to USPS hazmat requirements and Poshmark Terms of Service; $50 USPS noncompliance fee applies if improperly declared/labeled; Poshmark absorbs $45 of fee after August 1 2026, seller pays $5

> regulated contents (perfume, nail polish, aerosol sprays, electronics with lithium-ion batteries)

Source: <https://blog.poshmark.com/2026/07/09/59935/>

Aerosol sprays — Postal shipping restrictions by item category

carrier, conditions, restriction_type, scope


**Item category:** Aerosols

**Carrier:** USPS

**Restriction type:** hazmat declaration required

**Scope:** seller shipments (Etsy)

**Conditions:** May have special shipping requirements under USPS hazardous materials rules; $50 noncompliance fee for undeclared or improperly prepared hazardous materials effective July 12 2026

> Some items, such as certain candles, perfumes, aerosols, nail polish, or items containing lithium batteries, may have special shipping requirements.

Source: <https://www.valueaddedresource.net/poshmark-cover-usps-hazardous-non-compliance-fee/>

Aerosols — Postal shipping restrictions by item category


**Item category:** Aerosols (all types regardless of contents — hairspray, deodorant, cooking spray, spray paint, dry shampoo, aerosol sunscreen)

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic US

**Conditions:** Any aerosol is classified as pressurized container. Requires hazmat declaration. Cannot be shipped in poly mailers. $50 noncompliance fee if undeclared, effective July 12, 2026.

> Pressurized containers — any aerosol regardless of contents: hairspray, deodorant, cooking spray, spray paint, dry shampoo, aerosol sunscreen

Source: <https://selleressentials.com/usps-hazmat-noncompliance-fee-2026/>

Aerosols (all types regardless of contents — hairspray, deodorant, cooking spray, spray paint, dry shampoo, aerosol sunscreen) — Postal shipping restrictions by item category


**Item category:** Aerosols, corrosive, Packing Group II or III, (each not exceeding 1 L capacity)

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 2.2, UN1950, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B

> Aerosols, corrosive, Packing Group II or III, (each not exceeding 1 L capacity) 2.2 UN1950 n/a 2B 2B

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Aerosols, corrosive, Packing Group II or III, (each not exceeding 1 L capacity) — Postal shipping restrictions by item category


**Item category:** Aerosols, flammable (each not exceeding 1 L capacity)

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 2.1, UN1950, packing group n/a; domestic mail air: Prohibited; domestic mail surface: 2A

> Aerosols, flammable (each not exceeding 1 L capacity) 2.1 UN1950 n/a Prohibited 2A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Aerosols, flammable (each not exceeding 1 L capacity) — Postal shipping restrictions by item category


**Item category:** Aerosols, flammable, n.o.s. (engine starting fluid) (each not exceeding 1 L capacity)

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail: surface only (air prohibited)

**Conditions:** Hazard class 2.1, UN1950, packing group n/a; domestic mail air: Prohibited; domestic mail surface: 2A

> Aerosols, flammable, n.o.s. (engine starting fluid) (each not exceeding 1 L capacity) 2.1 UN1950 n/a Prohibited 2A

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Aerosols, flammable, n.o.s. (engine starting fluid) (each not exceeding 1 L capacity) — Postal shipping restrictions by item category


**Item category:** Aerosols, nonflammable (each not exceeding 1 L capacity)

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 2.2, UN1950, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B

> Aerosols, nonflammable (each not exceeding 1 L capacity) 2.2 UN1950 n/a 2B 2B

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Aerosols, nonflammable (each not exceeding 1 L capacity) — Postal shipping restrictions by item category


**Item category:** Aerosols, poison, each not exceeding 1 L capacity

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 2.2, UN1950, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B

> Aerosols, poison, each not exceeding 1 L capacity 2.2 UN1950 n/a 2B 2B

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Aerosols, poison, each not exceeding 1 L capacity — Postal shipping restrictions by item category


**Item category:** Aerosols

**Carrier:** USPS

**Restriction type:** allowed

**Scope:** domestic

**Conditions:** Make sure you read about the specific rules and restrictions for sending mailable gases.

> Make sure you read about the specific rules and restrictions for sending mailable gases.

Source: <https://www.usps.com/ship/shipping-restrictions.htm>

carrier, item_category, restriction_type, scope


**Item category:** Air bag inflators, or Air bag modules, or Seatbelt pretensioners

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 1.4G, UN0503, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> Air bag inflators, or Air bag modules, or Seatbelt pretensioners 1.4G UN0503 II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Air bag inflators, or Air bag modules, or Seatbelt pretensioners — Postal shipping restrictions by item category


**Item category:** Air Bags

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic

**Conditions:** Completely forbidden in the U.S. mail

> You can't send these items in the U.S. mail: Air Bags

Source: <https://www.usps.com/ship/shipping-restrictions.htm>

Air Bags — Postal shipping restrictions by item category


**Item category:** Air, compressed

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 2.2, UN1002, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B

> Air, compressed 2.2 UN1002 n/a 2B 2B

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Air, compressed — Postal shipping restrictions by item category


**Item category:** air guns - high muzzle velocity

**Carrier:** USPS

**Restriction type:** restricted

**Scope:** domestic mail

**Conditions:** Air guns with muzzle velocity of 400 or more feet per second must include Adult Signature service; mailers responsible for compliance with all applicable state and local regulations

> Shipments containing air guns with a muzzle velocity of 400 or more feet per second (fps) must include an Adult Signature service per DMM 503.8.

Source: <https://pe.usps.com/text/pub52/pub52c4_010.htm>

air guns - high muzzle velocity — Postal shipping restrictions by item category

carrier, conditions, item_category, scope


**Item category:** air guns

**Carrier:** USPS

**Restriction type:** allowed

**Scope:** domestic mail

**Conditions:** Air guns are not regulated as firearms unless manufactured with frames or receivers of an actual firearm; devices that expel projectiles using compressed air or gas including paintball and pellet guns

> Air guns are devices that expel projectiles using compressed air or other gas (including paintball and pellet guns). Air guns are not regulated as firearms unless they are manufactured with frames or receivers of an actual firearm.

Source: <https://pe.usps.com/text/pub52/pub52c4_009.htm>

air guns — Postal shipping restrictions by item category


**Item category:** Air, refrigerated liquid (cryogenic liquid), nonpressurized

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 2.2, UN1003, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited

> Air, refrigerated liquid (cryogenic liquid), nonpressurized 2.2 UN1003 n/a Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Air, refrigerated liquid (cryogenic liquid), nonpressurized — Postal shipping restrictions by item category


**Item category:** Air, refrigerated liquid (cryogenic liquid)

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 2.2, UN1003, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited

> Air, refrigerated liquid (cryogenic liquid) 2.2 UN1003 n/a Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Air, refrigerated liquid (cryogenic liquid) — Postal shipping restrictions by item category


**Item category:** Alcoholic beverages

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN3065, packing group II, III; domestic mail air: Prohibited; domestic mail surface: Prohibited

> Alcoholic beverages 3 UN3065 II, III Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Alcoholic beverages — Postal shipping restrictions by item category


**Item category:** Alcoholic Beverages

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic

**Conditions:** Beer, wine, and liquor may not be sent through the mail, except in limited circumstances.

> Beer, wine, and liquor may not be sent through the mail, except in limited circumstances.

Source: <https://www.usps.com/ship/shipping-restrictions.htm>

Alcoholic Beverages — Postal shipping restrictions by item category


**Item category:** Alcohols, flammable, toxic, n.o.s.

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN1986, packing group I, II, III; domestic mail air: Prohibited; domestic mail surface: Prohibited

> Alcohols, flammable, toxic, n.o.s. 3 UN1986 I, II, III Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Alcohols, flammable, toxic, n.o.s. — Postal shipping restrictions by item category


**Item category:** Alcohols, n.o.s.

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN1987, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited

> Alcohols, n.o.s. 3 UN1987 I Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Alcohols, n.o.s. — Postal shipping restrictions by item category


**Item category:** Aldehydes, flammable, toxic, n.o.s.

**Carrier:** USPS

**Restriction type:** prohibited

**Scope:** domestic mail (air and surface)

**Conditions:** Hazard class 3, UN1988, packing group I, II; domestic mail air: Prohibited; domestic mail surface: Prohibited

> Aldehydes, flammable, toxic, n.o.s. 3 UN1988 I, II Prohibited Prohibited

Source: <https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf>

Aldehydes, flammable, toxic, n.o.s. — Postal shipping restrictions by item category