Reference Source

3,068 records

Can I mail this substance or item?

3,068 records covering 2,878 item or substances, one fact each. Every value is transcribed from the source that states it and carries the sentence it was taken from: 38 sources across 13 sites, last checked 2026-08-03, due for re-check by 2027-08-03. Every record has a page of its own, quoting the line that states it.

Records3,068
Sources38
Verified
Review by
LicenceFacts extracted from public government and postal service web pages; not a reproduction of the original text

6 records where two or more sources state different values. Both sides are reproduced on the record page, each with its own source and quote.

About this data

Whether a named substance or item may be mailed, and on what conditions. Five records in six are the USPS hazardous materials table — Publication 52, Appendix A, 2,611 records — which is one row per Department of Transportation proper shipping name ('Ammonium metavanadate', 'Refrigerant gas R-404A', 'Diesel fuel'), carrying its hazard class, UN number, packing group, and whether it is prohibited or restricted in domestic mail by air and by surface. The remaining ~460 records are item-category rules of the kind a sender searches for by name: USPS's own consumer restriction pages, UK postal (Royal Mail, Post Office, Parcelforce, Royal Mail Wholesale), the UPU prohibited-articles entries for the US and UK, US CBP on the de minimis suspension, and six general duties from 49 CFR that bind every mode of transport and therefore bind the mail too. All three private couriers are covered as of 2026-09-01: FedEx (the International Connect prohibited and restricted item lists), UPS (the US Tariff/Terms and Conditions of Service — the items not accepted for transportation, plus the commodity sections on alcohol, marijuana and hemp, biological substances, firearms and ammunition, dry ice, limited quantity packages, hazardous waste and mercury, live animals, perishables, portable electronic devices, and tobacco and vaping), and DHL Express US (the prohibited commodities and the items needing prior approval, from DHL's own US 'what can I ship' page). Answers 'is UN2859 mailable', 'can I mail a lighter', 'USPS lithium battery mailing rules' and 'is [item] prohibited or restricted by [carrier]'. The carrier and scope fields on each record say whose rule it is and where it applies. For whether an item may be carried on an aircraft, which is a different question, see air-travel-item-restrictions — the 100 FAA, TSA, IATA and airline records that used to be in here moved there on 2026-10-07 and every one of their URLs still redirects.

The data

Item or substanceCarrierRestriction typeScopeConditionsDOT packing group
1,1,1,2-Tetrafluoroethane or Refrigerant gas R 134aUSPSrestricteddomestic mail (air and surface)Hazard class 2.2, UN3159, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B
1,1,1-TrichloroethaneUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2831, packing group III; domestic mail air: 6A; domestic mail surface: 6A
1,1,1-Trifluoroethane, compressed or Refrigerant gas R 143aUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 2.1, UN2035, packing group n/a; domestic mail air: Prohibited; domestic mail surface: 2A
1,1,2,2-TetrachloroethaneUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1702, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
1,1’-DiazoaminonaphthaleneUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
1,1-Dichloro-1-nitroethaneUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2650, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
1,1-DichloroethaneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2362, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
1,1-Difluoroethane or Refrigerant gas R 152aUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 2.1, UN1030, packing group n/a; domestic mail air: Prohibited; domestic mail surface: 2A
1,1-Difluoroethylene or Refrigerant gas R 1132aUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 2.1, UN1959, packing group n/a; domestic mail air: Prohibited; domestic mail surface: 2A
1,1-DimethoxyethaneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2377, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
1,1-Dinitroethane (dry)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
1,2,3,6-TetrahydrobenzaldehydeUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2498, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
1,2,3,6-TetrahydropyridineUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2410, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
1,2,4-Butanetriol trinitrateUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
1,2-Butylene oxide, stabilizedUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN3022, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
1,2-Di-(dimethylamino)ethaneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2372, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
1,2-DiazidoethaneUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
1,2-Dibromobutan-3-oneUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2648, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
1,2-Dichloro-1,1,2,2- Tetrafluoroethane or Refrigerant gas R 114USPSrestricteddomestic mail (air and surface)Hazard class 2.2, UN1958, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B
1,2-DichloroethyleneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1150, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
1,2-DichloropropaneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1279, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
1,2-DimethoxyethaneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2252, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
1,2-DinitroethaneUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
1,2-Epoxy-3-ethoxypropaneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2752, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
1,2-PropylenediamineUSPSprohibiteddomestic mail (air and surface)Hazard class 8, UN2258, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
1,3,5-Trimethyl-2,4,6-trinitrobenzeneUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
1,3,5-TrimethylbenzeneUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN2325, packing group III; domestic mail air: Prohibited; domestic mail surface: Prohibited
1,3,5-TrinitronaphthaleneUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
1,3-DiazopropaneUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
1,3-DichloroacetoneUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2649, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
1,3-Dichloropropanol2USPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2750, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
1,3-DimethylbutylamineUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN2379, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
1,3-Dinitro-4,5-dinitrosobenzeneUSPSprohibiteddomestic mail (air and surface)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 hydantoinUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
1,4-ButynediolUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2716, packing group III; domestic mail air: Prohibited; domestic mail surface: Prohibited
1,4-Dinitro-1,1,4,4- tetramethylolbutanetetranitrate (dry)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
1,5,9-CyclododecatrieneUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2518, packing group III; domestic mail air: 6A; domestic mail surface: 6A
1,7-Octadiene-3,5-diyne1,8- dimethoxy- 9-octadecynoic acidUSPSprohibiteddomestic mail (air and surface)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)USPSprohibiteddomestic mail (air and surface)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)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
1-Bromo-3-chloropropaneUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2688, packing group III; domestic mail air: 6A; domestic mail surface: 6A
1-Bromo-3-methylbutaneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2341, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
1-Bromo-3-nitrobenzene (unstable at 56° C)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
1-BromobutaneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1126, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
1-Chloro-1,1-difluoroethane or Refrigerant gas R 142bUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 2.1, UN2517, packing group n/a; domestic mail air: Prohibited; domestic mail surface: 2A
1-Chloro-1,2,2,2-tetrafluoroethane or Refrigerant gas R 124USPSrestricteddomestic mail (air and surface)Hazard class 2.2, UN1021, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B
1-Chloro-1,2,2,2-tetrafluoroethaneor Refrigerant gas R 124USPSrestricteddomestic mail (air and surface)Hazard class 2.2, UN1021, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B
1-Chloro-2,2,2-trifluoroethane or Refrigerant gas R 133aUSPSrestricteddomestic mail (air and surface)Hazard class 2.2, UN1983, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B
1-ChloropropaneUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN1278, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
1-EthylpiperidineUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN2386, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
1H-TetrazoleUSPSprohibiteddomestic mail (air and surface)Hazard class 1.1D, UN0504, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited
1-HexeneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2370, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
1-Hydroxybenzotriazole, monohydrateUSPSprohibiteddomestic mail (air and surface)Hazard class 4.1, UN3474, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
1-Methoxy-2-propanolUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN3092, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
1-MethylpiperidineUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN2399, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
1-NitrohydantoinUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
1-Pentene (n-amylene)USPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1108, packing group I; domestic mail air: Prohibited; domestic mail surface: 3A
1-PentolUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN2705, packing group II; domestic mail air: 8A; domestic mail surface: 8A
2,2’,3’,4,4’,6- HexanitrodiphenylamineUSPSprohibiteddomestic mail (air and surface)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)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
2-(2-Aminoethoxy) ethanolUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN3055, packing group III; domestic mail air: 8A; domestic mail surface: 8A
2,2-Di-(tert-butylperoxy) butane, with more than 55 percent in solutionUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
2,2’-Dichlorodiethyl etherUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1916, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
2,2-DimethylpropaneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 2.1, UN2044, packing group n/a; domestic mail air: Prohibited; domestic mail surface: 2A
2,2-DinitrostilbeneUSPSprohibiteddomestic mail (air and surface)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’-HexanitrodiphenyletherUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
2,3,4,6-TetranitrophenolUSPSprohibiteddomestic mail (air and surface)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 nitramineUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
2,3,4,6-TetranitrophenylnitramineUSPSprohibiteddomestic mail (air and surface)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- dinitrobenzeneUSPSprohibiteddomestic mail (air and surface)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)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
2,3-DihydropyranUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2376, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
2,3-DimethylbutaneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2457, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
2,4,6-Trinitro-1,3,5-triazido benzene (dry)USPSprohibiteddomestic mail (air and surface)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-diazobenzeneUSPSprohibiteddomestic mail (air and surface)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)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
2,4,6-Trinitrophenyl nitramineUSPSprohibiteddomestic mail (air and surface)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)USPSprohibiteddomestic mail (air and surface)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 nitraminoanisoleUSPSprohibiteddomestic mail (air and surface)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-trimethylbenzeneUSPSprohibiteddomestic mail (air and surface)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)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
2,4-Toluylenediamine, solid or 2,4- Toluenediamine, solidUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN1709, packing group III; domestic mail air: 6A; domestic mail surface: 6A
2,4-Toluylenediamine, solution or 2,4-Toluenediamine, solutionUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN3418, packing group III; domestic mail air: 6A; domestic mail surface: 6A
2,5-Dimethyl-2,5-dihydroperoxy hexane, with more than 82 percent with waterUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
2-Amino-4,6-Dinitrophenol, wetted with not less than 20 percent water by massUSPSprohibiteddomestic mail (air and surface)Hazard class 4.1, UN3317, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
2-Amino-4-chlorophenolUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2673, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
2-Amino-5-diethylaminopentaneUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2946, packing group III; domestic mail air: 6A; domestic mail surface: 6A
2-Bromo-2-nitropropane-1,3-diolUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 4.1, UN3241, packing group III; domestic mail air: Prohibited; domestic mail surface: 4A
2-BromobutaneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2339, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
2-Bromoethyl ethyl etherUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2340, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
2-BromopentaneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2343, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
2-ChloroethanalUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2232, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
2-ChloropropaneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2356, packing group I; domestic mail air: Prohibited; domestic mail surface: 3A
2-ChloropropeneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2456, packing group I; domestic mail air: Prohibited; domestic mail surface: 3A
2-Chloropropionic acidUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN2511, packing group III; domestic mail air: 8A; domestic mail surface: 8A
2-ChloropyridineUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2822, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
2-DiethylaminoethanolUSPSprohibiteddomestic mail (air and surface)Hazard class 8, UN2686, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
2-DimethylaminoacetonitrileUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN2378, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
2-DimethylaminoethanolUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN2051, packing group II; domestic mail air: 8A; domestic mail surface: 8A
2-Dimethylaminoethyl acrylateUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN3302, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
2-Dimethylaminoethyl methacrylateUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2522, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
2-EthylanilineUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2273, packing group III; domestic mail air: 6A; domestic mail surface: 6A
2-EthylbutanolUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2275, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
2-Ethylbutyl acetateUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1177, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
2-EthylbutyraldehydeUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1178, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
2-Ethylhexyl chloroformateUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2748, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
2-EthylhexylamineUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2276, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
2-IodobutaneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2390, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
2-Methyl-1-buteneUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN2459, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
2-Methyl-2-buteneUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN2460, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
2-Methyl-2-heptanethiolUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN3023, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
2-Methyl-5-ethylpyridineUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2300, packing group III; domestic mail air: 6A; domestic mail surface: 6A
2-MethylfuranUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2301, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
2-Methylpentan-2-olUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2560, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
2-Nitro-2-methylpropanol nitrateUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
2-TrifluoromethylanilineUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2942, packing group III; domestic mail air: 6A; domestic mail surface: 6A
3,3-DiethoxypropeneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2374, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
3,3’-IminodipropylamineUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN2269, packing group III; domestic mail air: 8A; domestic mail surface: 8A
3,5-Dichloro-2,4,6-trifluoropyridineUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, NA9264, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
3,5-Dinitrosalicylic acid (lead salt) (dry)USPSprohibiteddomestic mail (air and surface)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 dinitrateUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
3-BromopropyneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2345, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
3-Chloro-4-methylphenyl isocyanate, liquidUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2236, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
3-Chloro-4-methylphenyl isocyanate, solidUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN3428, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
3-Chloro-4-methylphenylisocyanate, liquidUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2236, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
3-Chloro-4-methylphenylisocyanate, solidUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN3428, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
3-Chloropropanol-1USPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2849, packing group III; domestic mail air: 6A; domestic mail surface: 6A
3-Diethylamino-propylamineUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2684, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
3-Methyl-1-buteneUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN2561, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
3-Methylbutan-2-oneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2397, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
3-Nitro-4-chlorobenzotrifluorideUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2307, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
3-TrifluoromethylanilineUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2948, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
4,4’-Diaminodiphenyl methaneUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2651, packing group III; domestic mail air: 6A; domestic mail surface: 6A
4,6-Dinitroresorcinol (heavy metal salts of) (dry)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
4-Bromo-1,2-dinitrobenzeneUSPSprohibiteddomestic mail (air and surface)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)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
4-Chloro-o-toluidine hydrochloride, solidUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN1579, packing group III; domestic mail air: 6A; domestic mail surface: 6A
4-Chloro-o-toluidine hydrochloride, solutionUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN3410, packing group III; domestic mail air: 6A; domestic mail surface: 6A
4-Methoxy-4-methylpentan-2-oneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2293, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
4-Methylmorpholine or n- methylmorpholineUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN2535, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
4-Nitrophenylhydrazine, with not less than 30 percent water, by massUSPSprohibiteddomestic mail (air and surface)Hazard class 4.1, UN3376, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
4-ThiapentanalUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2785, packing group III; domestic mail air: 6A; domestic mail surface: 6A
5-Azido-1-hydroxy tetrazoleUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
5-Mercaptotetrazol-1-acetic acidUSPSprohibiteddomestic mail (air and surface)Hazard class 1.4C, UN0448, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
5-Methylhexan-2-oneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2302, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
5-NitrobenzotriazolUSPSprohibiteddomestic mail (air and surface)Hazard class 1.1D, UN0385, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
5-tert-Butyl-2,4,6-trinitro-m-xylene or Musk xyleneUSPSprohibiteddomestic mail (air and surface)Hazard class 4.1, UN2956, packing group III; domestic mail air: Prohibited; domestic mail surface: Prohibited
5-tert-Butyl-2,4,6-trinitro-m-xyleneor Musk xyleneUSPSprohibiteddomestic mail (air and surface)Hazard class 4.1, UN2956, packing group III; domestic mail air: Prohibited; domestic mail surface: Prohibited
6-Nitro-4-diazotoluene-3-sulfonic acid (dry)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
9-Phosphabicyclononanes or Cyclooctadiene phosphinesUSPSprohibiteddomestic mail (air and surface)Hazard class 4.2, UN2940, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
a,a’-Di-(nitroxy) methyletherUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
a-Methylglucoside tetranitrateUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
a-Methylglycerol trinitrateUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
AcetalUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1088, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
AcetaldehydeUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN1089, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Acetaldehyde ammoniaUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 9, UN1841, packing group III; domestic mail air: Prohibited; domestic mail surface: 9C
Acetaldehyde oximeUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2332, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
Acetic acid (UN2790)USPSrestricteddomestic mail via air or surface transportationMailable if meets Limited Quantity requirements, contains less than 80% acid, and does not exceed 1 pint; Packaging Instruction 8A must be followed
Acetic anhydrideUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN1715, packing group II; domestic mail air: 8A; domestic mail surface: 8A
AcetoneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1090, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
Acetone cyanohydrin, stabilizedUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1541, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Acetone oilsUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1091, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
Acetone (UN1090), Benzene (UN1114), Hexane(s) (UN1208)USPSprohibitedall mailNonmailable unless diluted with less flammable or nonflammable materials sufficient to raise flashpoint to 20 F or higher
AcetonitrileUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1648, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
Acetyl acetone peroxide with more than 9 percent by mass active oxygenUSPSprohibiteddomestic mail (air and surface)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 solutionUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Acetyl bromideUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN1716, packing group II; domestic mail air: 8A; domestic mail surface: 8A
Acetyl chlorideUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN1717, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Acetyl iodideUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN1898, packing group II; domestic mail air: 8A; domestic mail surface: 8A
Acetyl methyl carbinolUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2621, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
Acetyl peroxide, solid, or with more than 25 percent in solutionUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Acetylene, dissolvedUSPSprohibiteddomestic mail (air and surface)Hazard class 2.1, UN1001, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited
Acetylene (liquified)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Acetylene silver nitrateUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Acetylene, solvent freeUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
AcridineUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2713, packing group III; domestic mail air: 6A; domestic mail surface: 6A
Acrolein dimer, stabilizedUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2607, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
Acrolein, stabilizedUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1092, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Acrylamide, solidUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2074, packing group III; domestic mail air: 6A; domestic mail surface: 6A
Acrylamide, solutionUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN3426, packing group III; domestic mail air: 6A; domestic mail surface: 6A
Acrylic acid, stabilizedUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN2218, packing group II; domestic mail air: 8A; domestic mail surface: 8A
Acrylonitrile, stabilizedUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN1093, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Adhesives and cements (UN1133)USPSrestricteddomestic mail via surface transportation onlyMailable only if qualifies as Limited Quantity surface material and meets conditions; Packaging Instruction 3A or 3B as applicable
Adhesives, containing a flammable liquidUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1133, packing group I, II, III; domestic mail air: Prohibited; domestic mail surface: 3A
AdiponitrileUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2205, packing group III; domestic mail air: 6A; domestic mail surface: 6A
Aerosol paint products (flammable compressed gas)USPSrestricteddomestic mail via surface transportation onlyAcceptable via surface transportation only if qualifies as Limited Quantity ground material and meets quantity limitations and applicable packaging requirements
AerosolsRoyal Mail Wholesale (Access customers)prohibitedUKIncludes spray paints, lacquers, solvents, air fresheners, oven cleaners, deodorants, body sprays, hair sprays, shaving and hair removal creams; inhalers with a volume of 50ml or less are allowed.
AerosolsUSPSrestricteddomesticMake sure you read about the specific rules and restrictions for sending mailable gases.
Aerosols, corrosive, Packing Group II or III, (each not exceeding 1 L capacity)USPSrestricteddomestic mail (air and surface)Hazard class 2.2, UN1950, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B
Aerosols, flammable (each not exceeding 1 L capacity)USPSrestricteddomestic mail: surface only (air prohibited)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)USPSrestricteddomestic mail: surface only (air prohibited)Hazard class 2.1, UN1950, packing group n/a; domestic mail air: Prohibited; domestic mail surface: 2A
Aerosols for toiletry or medicinal purposesRoyal Mail / ParcelforcerestrictedUK and International (Post Office counter)Valves must be protected to prevent inadvertent release; volume per item must not exceed 500ml; no more than two items in any one parcel, tightly packed; must be presented at the counter.
Aerosols, nonflammable (each not exceeding 1 L capacity)USPSrestricteddomestic mail (air and surface)Hazard class 2.2, UN1950, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B
Aerosols, poison, each not exceeding 1 L capacityUSPSrestricteddomestic mail (air and surface)Hazard class 2.2, UN1950, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B
Air bag inflators, or Air bag modules, or Seatbelt pretensionersUSPSprohibiteddomestic mail (air and surface)Hazard class 1.4G, UN0503, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Air BagsUSPSprohibiteddomesticCompletely forbidden in the U.S. mail
Air, compressedUSPSrestricteddomestic mail (air and surface)Hazard class 2.2, UN1002, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B
air gunsUSPSalloweddomestic mailAir 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 - high muzzle velocityUSPSrestricteddomestic mailAir 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
Air, refrigerated liquid (cryogenic liquid)USPSprohibiteddomestic mail (air and surface)Hazard class 2.2, UN1003, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited
Air, refrigerated liquid (cryogenic liquid), nonpressurizedUSPSprohibiteddomestic mail (air and surface)Hazard class 2.2, UN1003, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited
Alcoholates solution, n.o.s., in alcoholUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN3274, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Alcoholic Beveragessources differUSPSprohibiteddomesticBeer, wine, and liquor may not be sent through the mail, except in limited circumstances.
Alcoholic beverages and liquids containing more than 70% alcohol by volume (ABV)Royal Mail / Post OfficeprohibitedUK & International
Alcoholic beverages greater than 24% ABVRoyal Mail Wholesale (Access customers)prohibitedUKSpirits such as gin, vodka and whisky; beverages no greater than 24% ABV including beer, lager, wine and champagne are allowed.
Alcoholic beverages more than 24% but not more than 70% ABVRoyal Mail / ParcelforcerestrictedUK and International (Post Office counter)Volume must not exceed 1 litre per item; no more than two items in any one parcel; wrap in polythene, surround with absorbent material, mark FRAGILE for glass bottles; must be presented at the counter.
Alcohols, flammable, toxic, n.o.s.USPSprohibiteddomestic mail (air and surface)Hazard class 3, UN1986, packing group I, II, III; domestic mail air: Prohibited; domestic mail surface: Prohibited
Alcohols, n.o.s.USPSprohibiteddomestic mail (air and surface)Hazard class 3, UN1987, packing group I; domestic mail air: Prohibited; domestic mail surface: ProhibitedI
Alcohols, n.o.s.USPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1987, packing group II, III; domestic mail air: Prohibited; domestic mail surface: 3AII, III
Aldehydes, flammable, toxic, n.o.s.USPSprohibiteddomestic mail (air and surface)Hazard class 3, UN1988, packing group I, II; domestic mail air: Prohibited; domestic mail surface: ProhibitedI, II
Aldehydes, flammable, toxic, n.o.s.USPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1988, packing group III; domestic mail air: Prohibited; domestic mail surface: 3AIII
Aldehydes, n.o.s.USPSprohibiteddomestic mail (air and surface)Hazard class 3, UN1989, packing group I; domestic mail air: Prohibited; domestic mail surface: ProhibitedI
Aldehydes, n.o.s.USPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1989, packing group II, III; domestic mail air: Prohibited; domestic mail surface: 3AII, III
AldolUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2839, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Aldrin, liquidUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, NA2762, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Aldrin, solidUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, NA2761, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Alkali metal alcoholates, self-heating, corrosive, n.o.s.USPSprohibiteddomestic mail (air and surface)Hazard class 4.2, UN3206, packing group II, III; domestic mail air: Prohibited; domestic mail surface: Prohibited
Alkali metal alloys, liquid, n.o.s.USPSprohibiteddomestic mail (air and surface)Hazard class 4.3, UN1421, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Alkali metal amalgam, liquidUSPSprohibiteddomestic mail (air and surface)Hazard class 4.3, UN1389, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Alkali metal amalgam, solidUSPSprohibiteddomestic mail (air and surface)Hazard class 4.3, UN3401, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Alkali metal amidesUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 4.3, UN1390, packing group II; domestic mail air: Prohibited; domestic mail surface: 4A
Alkali metal dispersions, flammable or Alkaline earth metal dispersions, flammableUSPSprohibiteddomestic mail (air and surface)Hazard class 4.3, UN3482, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Alkali metal dispersions, or Alkaline earth metal dispersionsUSPSprohibiteddomestic mail (air and surface)Hazard class 4.3, UN1391, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Alkaline earth metal alcoholates, n.o.s.USPSprohibiteddomestic mail (air and surface)Hazard class 4.2, UN3205, packing group II, III; domestic mail air: Prohibited; domestic mail surface: Prohibited
Alkaline earth metal alloys, n.o.s.USPSrestricteddomestic mail: surface only (air prohibited)Hazard class 4.3, UN1393, packing group II; domestic mail air: Prohibited; domestic mail surface: 4A
Alkaline earth metal amalgams, liquidUSPSprohibiteddomestic mail (air and surface)Hazard class 4.3, UN1392, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Alkaline earth metal amalgams, solidUSPSprohibiteddomestic mail (air and surface)Hazard class 4.3, UN3402, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Alkaloids, liquid, n.o.s., or Alkaloid salts, liquid, n.o.s.USPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN3140, packing group I, II; domestic mail air: Prohibited; domestic mail surface: ProhibitedI, II
Alkaloids, liquid, n.o.s., or Alkaloid salts, liquid, n.o.s.USPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN3140, packing group III; domestic mail air: 6A; domestic mail surface: 6AIII
Alkaloids, solid, n.o.s. or Alkaloid salts, solid, n.o.s. poisonousUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1544, packing group I, II; domestic mail air: Prohibited; domestic mail surface: ProhibitedI, II
Alkaloids, solid, n.o.s. or Alkaloid salts, solid, n.o.s. poisonousUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN1544, packing group III; domestic mail air: 6A; domestic mail surface: 6AIII
Alkylphenols, liquid, n.o.s. (including C2-C12 homologues)USPSrestricteddomestic mail (air and surface)Hazard class 8, UN3145, packing group II, III; domestic mail air: 8A; domestic mail surface: 8A
Alkylphenols, liquid, n.o.s. (including C2C12 homologues)USPSprohibiteddomestic mail (air and surface)Hazard class 8, UN3145, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Alkylphenols, solid, n.o.s. (including C2-C12 homologues)USPSprohibiteddomestic mail (air and surface)Hazard class 8, UN2430, packing group I; domestic mail air: Prohibited; domestic mail surface: ProhibitedI
Alkylphenols, solid, n.o.s. (including C2-C12 homologues)USPSrestricteddomestic mail (air and surface)Hazard class 8, UN2430, packing group II, III; domestic mail air: 8A; domestic mail surface: 8AII, III
Alkylsulfuric acidsUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN2571, packing group II; domestic mail air: 8A; domestic mail surface: 8A
All commodities valued over US$20,000 without approvalFedExprohibitedinternational (FedEx International Connect)valued over US$20,000 without approval
All flammable liquids with flashpoint of 20 F (-7 C) or belowUSPSprohibitedall mailAll flammable liquids with flashpoint at or below 20 F are prohibited from mailing
Allyl acetateUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN2333, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Allyl alcoholUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1098, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Allyl bromideUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN1099, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Allyl chlorideUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN1100, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Allyl chloroformateUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1722, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Allyl ethyl etherUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN2335, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Allyl formateUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN2336, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Allyl glycidyl etherUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2219, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
Allyl iodideUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN1723, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Allyl isothiocyanate, stabilizedUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1545, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
AllylamineUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2334, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Allyltrichlorosilane, stabilizedUSPSprohibiteddomestic mail (air and surface)Hazard class 8, UN1724, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
alpha-Methylbenzyl alcohol, liquidUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2937, packing group III; domestic mail air: 6A; domestic mail surface: 6A
alpha-Methylbenzyl alcohol, solidUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN3438, packing group III; domestic mail air: 6A; domestic mail surface: 6A
alpha-MethylvaleraldehydeUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2367, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
Alpha-NaphthylamineUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2077, packing group III; domestic mail air: 6A; domestic mail surface: 6A
Alpha-PineneUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2368, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
Aluminum borohydride or Aluminum borohydride in devicesUSPSprohibiteddomestic mail (air and surface)Hazard class 4.2, UN2870, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Aluminum bromide, anhydrousUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN1725, packing group II; domestic mail air: 8A; domestic mail surface: 8A
Aluminum bromide, solutionUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN2580, packing group III; domestic mail air: 8A; domestic mail surface: 8A
Aluminum carbideUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 4.3, UN1394, packing group II; domestic mail air: Prohibited; domestic mail surface: 4A
Aluminum chloride, anhydrousUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN1726, packing group II; domestic mail air: 8A; domestic mail surface: 8A
Aluminum chloride, solutionUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN2581, packing group III; domestic mail air: 8A; domestic mail surface: 8A
Aluminum dross, wet or hotUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Aluminum ferrosilicon powderUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 4.3, UN1395, packing group II, III; domestic mail air: Prohibited; domestic mail surface: 4A
Aluminum hydrideUSPSprohibiteddomestic mail (air and surface)Hazard class 4.3, UN2463, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Aluminum, moltenUSPSprohibiteddomestic mail (air and surface)Hazard class 9, NA9260, packing group III; domestic mail air: Prohibited; domestic mail surface: Prohibited
Aluminum, nitrateUSPSrestricteddomestic mail (air and surface)Hazard class 5.1, UN1438, packing group III; domestic mail air: 5A; domestic mail surface: 5A
Aluminum phosphideUSPSprohibiteddomestic mail (air and surface)Hazard class 4.3, UN1397, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Aluminum phosphide pesticidesUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN3048, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Aluminum powder, coatedUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 4.1, UN1309, packing group II, III; domestic mail air: Prohibited; domestic mail surface: 4A
Aluminum powder, uncoatedUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 4.3, UN1396, packing group II, III; domestic mail air: Prohibited; domestic mail surface: 4A
Aluminum resinateUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 4.1, UN2715, packing group III; domestic mail air: Prohibited; domestic mail surface: 4A
Aluminum silicon powder, uncoatedUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 4.3, UN1398, packing group III; domestic mail air: Prohibited; domestic mail surface: 4A
Aluminum smelting by-products or Aluminum remelting by-productsUSPSprohibiteddomestic mail (air and surface)Hazard class 4.3, UN3170, packing group II, III; domestic mail air: Prohibited; domestic mail surface: Prohibited
Amine, flammable, corrosive, n.o.s. or Polyamines, flammable, corrosive, n.o.s.USPSprohibiteddomestic mail (air and surface)Hazard class 3, UN2733, packing group I, II; domestic mail air: Prohibited; domestic mail surface: ProhibitedI, II
Amine, flammable, corrosive, n.o.s. or Polyamines, flammable, corrosive, n.o.s.USPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2733, packing group III; domestic mail air: Prohibited; domestic mail surface: 3AIII
Amines, liquid, corrosive, n.o.s. or Polyamines, liquid, corrosive, n.o.s.USPSprohibiteddomestic mail (air and surface)Hazard class 8, UN2735, packing group I; domestic mail air: Prohibited; domestic mail surface: ProhibitedI
Amines, liquid, corrosive, n.o.s. or Polyamines, liquid, corrosive, n.o.s.USPSrestricteddomestic mail (air and surface)Hazard class 8, UN2735, packing group II, III; domestic mail air: 8A; domestic mail surface: 8AII, III
Amines, solid, corrosive, n.o.s. or Polyamines, solid, corrosive, n.o.s.USPSprohibiteddomestic mail (air and surface)Hazard class 8, UN3259, packing group I; domestic mail air: Prohibited; domestic mail surface: ProhibitedI
Amines, solid, corrosive, n.o.s. or Polyamines, solid, corrosive, n.o.s.USPSrestricteddomestic mail (air and surface)Hazard class 8, UN3259, packing group II, III; domestic mail air: 8A; domestic mail surface: 8AII, III
Aminophenols (o-; m-; p-)USPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2512, packing group III; domestic mail air: 6A; domestic mail surface: 6A
Aminopyridines (o-; m-; p-)USPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2671, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammonia, anhydrous (domestic)USPSprohibiteddomestic mail (air and surface)Hazard class 2.2, UN1005, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammonia, anhydrous (international)USPSprohibiteddomestic mail (air and surface)Hazard class 2.3, UN1005, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammonium arsenateUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1546, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammonium azideUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Ammonium bromateUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Ammonium chlorateUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Ammonium dichromateUSPSrestricteddomestic mail (air and surface)Hazard class 5.1, UN1439, packing group II; domestic mail air: 5A; domestic mail surface: 5A
Ammonium dinitro-o-cresolate, solidUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1843, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammonium dinitro-o-cresolate, solutionUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN3424, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammonium fluorideUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2505, packing group III; domestic mail air: 6A; domestic mail surface: 6A
Ammonium fluorosilicateUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2854, packing group III; domestic mail air: 6A; domestic mail surface: 6A
Ammonium fulminateUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Ammonium hydrogen sulfateUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN2506, packing group II; domestic mail air: 8A; domestic mail surface: 8A
Ammonium hydrogendiflouride, solutionUSPSprohibiteddomestic mail (air and surface)Hazard class 8, UN2817, packing group II; domestic mail air: Prohibited; domestic mail surface: ProhibitedII
Ammonium hydrogendiflouride, solutionUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN2817, packing group III; domestic mail air: 8A; domestic mail surface: 8AIII
Ammonium hydrogendifluoride, solidUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN1727, packing group II; domestic mail air: 8A; domestic mail surface: 8A
Ammonium metavanadateUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2859, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammonium nitrateUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Ammonium nitrate based fertilizersUSPSrestricteddomestic mail (air and surface)Hazard class 5.1, UN2067, packing group III; domestic mail air: 5A; domestic mail surface: 5A
Ammonium nitrate fertilizersUSPSrestricteddomestic mail (air and surface)Hazard class 5.1, NA2072, packing group III; domestic mail air: 5A; domestic mail surface: 5A
Ammonium nitrate, liquid (hot concentrated solution)USPSprohibiteddomestic mail (air and surface)Hazard class 5.1, UN2426, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammonium nitrate mixed fertilizersUSPSrestricteddomestic mail (air and surface)Hazard class 5.1, NA2069, packing group III; domestic mail air: 5A; domestic mail surface: 5A
Ammonium perchlorateUSPSprohibiteddomestic mail (air and surface)Hazard class 1.1D, UN0402, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammonium permanganateUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Ammonium persulfateUSPSrestricteddomestic mail (air and surface)Hazard class 5.1, UN1444, packing group III; domestic mail air: 5A; domestic mail surface: 5A
Ammonium picrate, dry or wetted with less than 10 percent water, by massUSPSprohibiteddomestic mail (air and surface)Hazard class 1.1D, UN0004, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammonium picrate, wetted with not less than 10 percent water, by massUSPSprohibiteddomestic mail (air and surface)Hazard class 4.1, UN1310, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammonium polysulfide, solutionUSPSprohibiteddomestic mail (air and surface)Hazard class 8, UN2818, packing group II; domestic mail air: Prohibited; domestic mail surface: ProhibitedII
Ammonium polysulfide, solutionUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN2818, packing group III; domestic mail air: 8A; domestic mail surface: 8AIII
Ammonium polyvanadateUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2861, packing group II; domestic mail air: 6A; domestic mail surface: 6A
Ammonium sulfide solutionUSPSprohibiteddomestic mail (air and surface)Hazard class 8, UN2683, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
AmmunitionRoyal Mail / Post OfficeprohibitedUK & International(excluding lead pellets and other airgun and airsoft projectiles)
AmmunitionRoyal Mail Wholesale (Access customers)prohibitedUKExcept lead pellets.
AmmunitionUPSrestrictedUnited Stateswhere such ammunition constitutes
AmmunitionUSPSprohibiteddomesticCompletely forbidden in the U.S. mail
Ammunition, practiceUSPSprohibiteddomestic mail (air and surface)Hazard class 1.4G, UN0362, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammunition, proofUSPSprohibiteddomestic mail (air and surface)Hazard class 1.4G, UN0363, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammunition, smoke, with or without burster, expelling charge, or propelling chargeUSPSprohibiteddomestic mail (air and surface)Hazard class 1.2G, UN0015, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammunition, tear-producing with burster, expelling charge, or propelling chargeUSPSprohibiteddomestic mail (air and surface)Hazard class 1.2G, UN0018, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammunition, toxic, nonexplosive, without burster or expelling charge, non-fuzedUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2016, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Ammunition, toxic with burster, expelling charge, or propelling chargeUSPSprohibiteddomestic mail (air and surface)Hazard class 1.2K, UN0020, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Amyl acetatesUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1104, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
Amyl acid phosphateUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN2819, packing group III; domestic mail air: 8A; domestic mail surface: 8A
Amyl butyratesUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2620, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
Amyl chloridesUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1107, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
Amyl formatesUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1109, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
Amyl mercaptansUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN1111, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Amyl nitrateUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1112, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
Amyl nitritesUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1113, packing group II; domestic mail air: Prohibited; domestic mail surface: 3A
AmylaminesUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN1106, packing group II; domestic mail air: Prohibited; domestic mail surface: ProhibitedII
AmylaminesUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN1106, packing group III; domestic mail air: Prohibited; domestic mail surface: 3AIII
AmyltrichlorosilaneUSPSprohibiteddomestic mail (air and surface)Hazard class 8, UN1728, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
AnilineUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1547, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Aniline hydrochlorideUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN1548, packing group III; domestic mail air: 6A; domestic mail surface: 6A
Animal furs and skinsInternational mail to the United Kingdom (UPU list)restrictedinbound international mail to the United KingdomFur and skin of endangered animals or fish, or goods made from them, are banned for trade import into the UK unless you have a valid permit; furs of animals caught in leg-hold traps are prohibited unless accompanied by approved-source certification or a valid permit.
AnisidinesUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2431, packing group III; domestic mail air: 6A; domestic mail surface: 6A
AnisoleUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, UN2222, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
Anisoyl chlorideUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN1729, packing group II; domestic mail air: 8A; domestic mail surface: 8A
Antimony compounds, inorganic, liquid, n.o.s.USPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN3141, packing group III; domestic mail air: 6A; domestic mail surface: 6A
Antimony compounds, inorganic, solid, n.o.s.USPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN1549, packing group III; domestic mail air: 6A; domestic mail surface: 6A
Antimony lactateUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN1550, packing group III; domestic mail air: 6A; domestic mail surface: 6A
Antimony pentachloride, liquidUSPSprohibiteddomestic mail (air and surface)Hazard class 8, UN1730, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Antimony pentachloride, solutionsUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN1731, packing group II, III; domestic mail air: 8A; domestic mail surface: 8A
Antimony pentafluorideUSPSprohibiteddomestic mail (air and surface)Hazard class 8, UN1732, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Antimony potassium tartrateUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN1551, packing group III; domestic mail air: 6A; domestic mail surface: 6A
Antimony powderUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2871, packing group III; domestic mail air: 6A; domestic mail surface: 6A
Antimony sulfide and a chlorate, mixtures ofUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Antimony tribromide, solidUSPSrestricteddomestic mail (air and surface)Hazard class 8, NA1549, packing group II; domestic mail air: 8A; domestic mail surface: 8A
Antimony tribromide, solutionUSPSrestricteddomestic mail (air and surface)Hazard class 8, NA1549, packing group II; domestic mail air: 8A; domestic mail surface: 8A
Antimony trichloride, liquidUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN1733, packing group II; domestic mail air: 8A; domestic mail surface: 8A
Antimony trichloride, solidUSPSrestricteddomestic mail (air and surface)Hazard class 8, UN1733, packing group II; domestic mail air: 8A; domestic mail surface: 8A
Antimony, trifluoride, solidUSPSrestricteddomestic mail (air and surface)Hazard class 8, NA1549, packing group II; domestic mail air: 8A; domestic mail surface: 8A
Antimony, trifluoride, solutionUSPSrestricteddomestic mail (air and surface)Hazard class 8, NA1549, packing group II; domestic mail air: 8A; domestic mail surface: 8A
Antiques, works of art, and fine artDHLrestrictedUnited States
Any Package with an actual value of more than $50,000UPSprohibitedUnited Statesexcept that the actual value of Packages declared in accordance with the Enhanced Maximum Declared Value provisions of Section 55.1
Any pallet with an actual value of more than $100,000UPSprohibitedUnited States
Argon, compressedUSPSrestricteddomestic mail (air and surface)Hazard class 2.2, UN1006, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B
Argon, refrigerated liquid (cryogenic liquid)USPSprohibiteddomestic mail (air and surface)Hazard class 2.2, UN1951, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited
ArsenicUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1558, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Arsenic acid, liquidUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1553, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Arsenic acid, solidUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1554, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Arsenic bromideUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1555, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Arsenic pentoxideUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1559, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Arsenic sulfideUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, NA1557, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Arsenic sulfide and a chlorate, mixtures ofUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Arsenic trichlorideUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1560, packing group I; domestic mail air: Prohibited; domestic mail surface: Prohibited
Arsenic trioxideUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1561, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Arsenic trisulfideUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, NA1557, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Arsenical dustUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN1562, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Arsenical pesticides, liquid, flammable, toxic, flashpoint less than 23° CUSPSprohibiteddomestic mail (air and surface)Hazard class 3, UN2760, packing group I, II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Arsenical pesticides, liquid, toxicUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2994, packing group I, II; domestic mail air: Prohibited; domestic mail surface: ProhibitedI, II
Arsenical pesticides, liquid, toxicUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2994, packing group III; domestic mail air: 6A; domestic mail surface: 6AIII
Arsenical pesticides, liquid, toxic, flammable flashpoint not less than 23° CUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2993, packing group I, II; domestic mail air: Prohibited; domestic mail surface: ProhibitedI, II
Arsenical pesticides, liquid, toxic, flammable flashpoint not less than 23° CUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2993, packing group III; domestic mail air: 6A; domestic mail surface: 6AIII
Arsenical pesticides, solid, toxicUSPSprohibiteddomestic mail (air and surface)Hazard class 6.1, UN2759, packing group I, II; domestic mail air: Prohibited; domestic mail surface: ProhibitedI, II
Arsenical pesticides, solid, toxicUSPSrestricteddomestic mail (air and surface)Hazard class 6.1, UN2759, packing group III; domestic mail air: 6A; domestic mail surface: 6AIII
ArsineUSPSprohibiteddomestic mail (air and surface)Hazard class 2.3, UN2188, packing group n/a; domestic mail air: Prohibited; domestic mail surface: Prohibited
Articles, explosive, extremely insensitive or Articles, EEIUSPSprohibiteddomestic mail (air and surface)Hazard class 1.6N, UN0486, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Articles, explosive, n.o.s.USPSprohibiteddomestic mail (air and surface)Hazard class 1.4S, UN0349, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Articles infringing trade mark or copyrightRoyal Mail / ParcelforceprohibitedUK and International (Post Office counter)Articles infringing trade mark or copyright are prohibited.
Articles made from natural or depleted uranium or natural thorium (UN2909)USPSrestricteddomestic mail via surface transportationMailable if activity does not exceed limits in Exhibit 347.22; classified as excepted package per 49 CFR 172.101; must follow Packaging Instruction 7A
Articles, pressurized pneumatic or Hydraulic containing nonflammable gasUSPSrestricteddomestic mail (air and surface)Hazard class 2.2, UN3164, packing group n/a; domestic mail air: 2B; domestic mail surface: 2B
Articles, pyrophoricUSPSprohibiteddomestic mail (air and surface)Hazard class 1.2L, UN0380, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Articles, pyrotechnic for technical purposesUSPSprohibiteddomestic mail (air and surface)Hazard class 1.1G, UN0428, packing group II; domestic mail air: Prohibited; domestic mail surface: Prohibited
Artwork, archeological artifacts and antiquitiesFedExrestrictedinternational (FedEx International Connect)
AsbestosDHLprohibitedUnited States
AsbestosRoyal Mail / Post OfficerestrictedUK only (international mail prohibited)UK – not allowed in the mail (except when sent as a sample fixed in a resin, plastic or glass matrix), prohibited from Parcelforce Worldwide services IMPORTANT: excludes damaged, friable, or suspect asbestos material intended for analysis which is strictly prohibited.
AsbestosRoyal Mail Wholesale (Access customers)prohibitedUKExcept when sent as a sample fixed in a resin, plastic or glass matrix.
AsbestosUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 9, NA2212, packing group III; domestic mail air: Prohibited; domestic mail surface: 9C
Ascaridole (organic peroxide)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Asphalt, at or above its flashpointUSPSrestricteddomestic mail: surface only (air prohibited)Hazard class 3, NA1999, packing group III; domestic mail air: Prohibited; domestic mail surface: 3A
Audible fire alarm systems powered by compressed gasUSPSrestricteddomestic mail via surface transportationAcceptable via surface transportation if comply with conditions in Packaging Instruction 2E
Auto parts with fluids in themFedExprohibitedinternational (FedEx International Connect)with fluids in them
Aviation regulated liquid, n.o.s.USPSrestricteddomestic mail (air and surface)Hazard class 9, UN3334, packing group n/a; domestic mail air: 9C; domestic mail surface: 9C
Aviation regulated solid, n.o.s.USPSrestricteddomestic mail (air and surface)Hazard class 9, UN3335, packing group n/a; domestic mail air: 9C; domestic mail surface: 9C
Azaurolic, acid (salt of), (dry)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Azido guanidine picrate (dry)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Azido hydroxy tetrazole (mercury and silver salts)USPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.
Azidodithiocarbonic acidUSPSprohibiteddomestic mail (air and surface)Listed as Forbidden in the Pub 52 Appendix A mailability guide; Prohibited in domestic mail by air and by surface.

Showing the first 400 of 3,068 records. Every record has its own page, with its source and the quoted line that states it; these list the rest.

Where this came from

Every record above links the page it was taken from and quotes the sentence that states it. These are the 38 sources this dataset was assembled from.

Machine-readable

From your own code

Same records, same quotes, without scraping the page: refsource is on PyPI and npm. Each value comes back carrying the URL it was read from and the sentence on that page that states it — .source and .quote sit on the value itself rather than in a side channel, so the checking step is available instead of skipped.

pip install refsource
refsource lookup shipping-restrictions-by-class carrier=USPS

npx -y refsource lookup shipping-restrictions-by-class carrier=USPS

Set your AI assistant up to use this

Two files and no account. Put this in .mcp.json at the root of your project — Claude Code, Cursor, Windsurf, VS Code and Codex all read that file — and your assistant can look this dataset up instead of recalling it. The server is remote, keyless and read-only.

{
  "mcpServers": {
    "referencesource": {
      "type": "http",
      "url": "https://referencesource.org/mcp"
    }
  }
}

Add to Cursor · or, on the command line: claude mcp add --transport http referencesource https://referencesource.org/mcp --scope project

Then one line in the project's CLAUDE.md or AGENTS.md, so the assistant knows when to reach for it:

When a question needs "What can be mailed: USPS hazardous materials, plus item rules for post and couriers", call the referencesource MCP server at https://referencesource.org/mcp (tool `search_records`, dataset_slug `shipping-restrictions-by-class`) instead of answering from memory — every record it returns carries its source URL and a verbatim quote from that page.

What each tool does, and the servers built over single registers: Connect your AI assistant.

3,068 records. last verified against source . due for re-check by .

Licence. Facts extracted from public government and postal service web pages; not a reproduction of the original text