Records 1,601–2,000 — What can be mailed: USPS hazardous materials, plus item rules for post and couriers

Records 1,601 to 2,000 of 3,068. Each links to its own page, which carries the source URL and the quoted line that states the value.

• Lighters, fuse · USPSLighters, fuse 1.4S UN0131 II Prohibited Prohibited
• Lighters, non-pressurized, containing flammable liquid · USPSLighters, non-pressurized, containing flammable liquid 3 NA1057 II Prohibited 3C
• Lighters with ignition elements containing liquid fuel or flammable gas · USPSLighters with ignition elements and containing liquid fuel are classified as a Class 3 flammable liquid; those containing flammable gas are Division 2.1. Mailing is permitted only
• Limited Quantity Packages · UPSLimited Quantity Packages are accepted for transportation without Hazardous Materials shipping papers and without a contract, only within the 48 contigu- ous United States via UPS
• Liquid Mercury · USPSLiquid mercury in any amount (and devices containing a visible amount of mercury) is prohibited from the US Mail, so you must find another carrier.
• Liquid with flashpoint above 200 F (93 C) · USPSA liquid with a flashpoint above 200° F (93° C) is not regulated as a hazardous material and may be mailed subject to the general packaging requirements in DMM 601
• Liquids over 1 litre · Royal Mail / Post OfficeLiquids over 1 litre International – not allowed in the mail UK – allowed in the mail, see restrictions and packaging guidelines below: Items must be securely closed and placed in
• Liquids over 1 litre (not classified as dangerous goods) · Royal Mail / ParcelforceLiquids over 1 litre (containing liquids not classified as dangerous goods) Packaging guidelines: Items must be securely closed and placed in a leak-proof liner, such as a sealed p
• Liquids under 1 litre · Royal Mail / Post OfficeLiquids under 1 litre UK & International – allowed in the mail, see restrictions and packaging guidelines below: Items must be securely closed and placed in a leak-proof inner line
• Liquified gas, flammable, n.o.s. · USPSLiquified gas, flammable, n.o.s. 2.1 UN3161 n/a Prohibited 2A
• Liquified gas, n.o.s. · USPSLiquified gas, n.o.s. 2.2 UN3163 n/a 2B 2B
• Liquified gas, oxidizing, n.o.s. · USPSLiquified gas, oxidizing, n.o.s. 2.2 UN3157 n/a 2B 2B
• Liquified gas, toxic, corrosive, n.o.s. Inhalation Hazard Zone A, B, C, or D · USPSLiquified gas, toxic, corrosive, n.o.s. Inhalation Hazard Zone A, B, C, or D 2.3 UN3308 n/a Prohibited Prohibited
• Liquified gas, toxic, flammable, corrosive, n.o.s. Inhalation Hazard Zone A, B, C, or D · USPSLiquified gas, toxic, flammable, corrosive, n.o.s. Inhalation Hazard Zone A, B, C, or D 2.3 UN3309 n/a Prohibited Prohibited
• Liquified gas, toxic, flammable, n.o.s. Inhalation Hazard Zone A, B, C, or D · USPSLiquified gas, toxic, flammable, n.o.s. Inhalation Hazard Zone A, B, C, or D 2.3 UN3160 n/a Prohibited Prohibited
• Liquified gas, toxic, n.o.s. Inhalation Hazard Zone A, B, C, or D · USPSLiquified gas, toxic, n.o.s. Inhalation Hazard Zone A, B, C, or D 2.3 UN3162 n/a Prohibited Prohibited
• Liquified gas, toxic, oxidizing, corrosive, n.o.s. Inhalation Hazard Zone A, B, C, or D · USPSLiquified gas, toxic, oxidizing, corrosive, n.o.s. Inhalation Hazard Zone A, B, C, or D 2.3 UN3310 n/a Prohibited Prohibited
• Liquified gas, toxic, oxidizing, n.o.s. Inhalation Hazard Zone A, B, C, or D · USPSLiquified gas, toxic, oxidizing, n.o.s. Inhalation Hazard Zone A, B, C, or D 2.3 UN3307 n/a Prohibited Prohibited
• Liquified gases, nonflammable charged with nitrogen, carbon dioxide, or air · USPSLiquified gases, nonflammable charged with nitrogen, carbon dioxide, or air 2.2 UN1058 n/a 2B 2B
• Lithium · USPSLithium 4.3 UN1415 I Prohibited 4A
• Lithium aluminum hydride · USPSLithium aluminum hydride 4.3 UN1410 I Prohibited Prohibited
• Lithium aluminum hydride, ethereal · USPSLithium aluminum hydride, ethereal 4.3 UN1411 I Prohibited Prohibited
• Lithium Batteries · USPSLithium Batteries For domestic mailings only, small consumer-type primary lithium cells or batteries (lithium metal or lithium alloy) like those used to power cameras and flashligh
• Lithium Batteries in Electronic Devices · USPSLithium Batteries in Electronic Devices If you're mailing pre-owned, damaged, or defective electronic devices containing or packaged with lithium batteries, you must send them via
• Lithium borohydride · USPSLithium borohydride 4.3 UN1413 I Prohibited Prohibited
• Lithium ferrosilicon · USPSLithium ferrosilicon 4.3 UN2830 II Prohibited 4A
• Lithium hydride · USPSLithium hydride 4.3 UN1414 I Prohibited 4A
• Lithium hydride, fused solid · USPSLithium hydride, fused solid 4.3 UN2805 II Prohibited 4A
• Lithium hydroxide, monohydrate or Lithium hydroxide, solid · USPSLithium hydroxide, monohydrate or Lithium hydroxide, solid 8 UN2680 II 8A 8A
• Lithium hydroxide, solution · USPSLithium hydroxide, solution 8 UN2679 II, III 8A 8A
• Lithium hypochlorite, dry or Lithium hypochlorite mixture · USPSLithium hypochlorite, dry or Lithium hypochlorite mixture 5.1 UN1471 II 5A 5A
• Lithium ion and lithium metal batteries · FedExLithium ion and lithium metal batteries
• Lithium-ion batteries (including lithium polymer batteries) · USPSLithium-ion batteries (including lithium polymer batteries) 9 UN3480 N/A Prohibited 9D
• Lithium-ion batteries (including lithium polymer batteries) contained in equipment · USPSLithium-ion batteries (including lithium polymer batteries) contained in equipment 9 UN3481 N/A 9D 9D
• Lithium-ion batteries (including lithium polymer batteries) packed with equipment · USPSLithium-ion batteries (including lithium polymer batteries) packed with equipment 9 UN3481 N/A 9D 9D
• Lithium-ion (rechargeable) batteries without equipment (individual batteries) · USPSLithium-ion or Lithium Polymer Batteries 5, 6
• Lithium metal batteries (including lithium alloy batteries) · USPSLithium metal batteries (including lithium alloy batteries) 9 UN3090 N/A Prohibited 9D
• Lithium metal batteries (including lithium alloy batteries) contained in equipment · USPSLithium metal batteries (including lithium alloy batteries) contained in equipment 9 UN3091 N/A 9D 9D
• Lithium metal batteries (including lithium alloy batteries) packed with equipment · USPSLithium metal batteries (including lithium alloy batteries) packed with equipment 9 UN3091 N/A 9D 9D
• Lithium metal (non-rechargeable) batteries without equipment (individual batteries) · USPSWithout the equipment they operate (individual batteries in originally sealed packaging)
• Lithium peroxide · USPSLithium peroxide 5.1 UN1472 II 5A 5A
• Lithium silicon · USPSLithium silicon 4.3 UN1417 II Prohibited 5A
• Live animal Shipments · UPSUPS provides service on a limited basis for some types of live animal Shipments. (The term “animal” as used here refers to anything living, except plants.) Live animals may be ship
• Live animals · DHLLive animals, including mammals, reptiles, fish, invertebrates, amphibians, insects, or birds
• Live Animals · USPSShipments of live animals, including poultry, reptiles, and bees, have very specific packaging requirements.
• Live creatures, insects and invertebrates · Royal Mail / ParcelforceLive animals and reptiles are prohibited, as are any creatures or insects classified as dangerous within the Dangerous Wild Animals Act 1976 (including certain venomous spiders).
• Live creatures, insects and invertebrates · Royal Mail / Post OfficeLive creatures, insects and invertebrates (including bees, caterpillars, cockroaches, crickets, destroyers of noxious pests, earthworms, leeches and other parasites, lugworms, magg
• live day-old poultry - mailable types · USPSThe following types of live, day-old poultry are acceptable for mailing when properly packaged:
• live day-old poultry vaccinated with Newcastle disease (live virus) · USPSDay-old poultry vaccinated with Newcastle disease (live virus) also is nonmailable.
• live scorpions · USPSscorpions are mailable only when sent for the purposes of medical research or the manufacturing of antivenin. Scorpions are nonmailable under any other circumstances.
• Livestock, bloodstock and living animals · FedExLivestock, bloodstock and living animals
• Living creatures, animals and reptiles · Royal Mail Wholesale (Access customers)Living creatures, animals and reptiles Except certain insects and invertebrates.
• London purple · USPSLondon purple 6.1 UN1621 II 6A 6A
• Loose precious and semi-precious stones · DHLLoose precious and semi-precious stones, whether cut or uncut, polished or unpolished
• Lottery tickets · Royal Mail / Post OfficeLottery tickets International – not allowed in the mail UK – not allowed in the mail (except UK lottery tickets)
• Lottery tickets · Royal Mail Wholesale (Access customers)Lottery tickets Except UK lottery tickets.
• Low-risk radioactive material (UN2910) — limited quantity excepted package · USPSUN2910: Low-risk radioactive material classified as "limited quantity" and "excepted package" under 49 CFR § 172.101.
• Low-value imports sent through the international postal network (de minimis) · US CBP (international postal network)Executive Order 14324 also establishes a new duty rate for covered products that are sent to the United States through the international postal network.
• Low-value imports valued at $800 or less (de minimis, all countries) · US CBP (imports into the United States)Executive Order 14324 suspends the duty-free de minimis exemption otherwise authorized under section 321(a)(2)(C) of the Tariff Act of 1930, as amended, for all covered products, r
• m-Nitrobenzene diazonium perchlorate · USPSm-Nitrobenzene diazonium perchlorate Forbidden Prohibited Prohibited Prohibited Prohibited
• m-Nitrophenyldinitro methane · USPSm-Nitrophenyldinitro methane Forbidden Prohibited Prohibited Prohibited Prohibited
• m-Phenylene diaminediperchlorate (dry) · USPSm-Phenylene diaminediperchlorate (dry) Forbidden Prohibited Prohibited Prohibited Prohibited
• Magnesium aluminum phosphide · USPSMagnesium aluminum phosphide 4.3 UN1419 I Prohibited Prohibited
• Magnesium arsenate · USPSMagnesium arsenate 6.1 UN1622 II Prohibited Prohibited
• Magnesium bromate · USPSMagnesium bromate 5.1 UN1473 II 5A 5A
• Magnesium chlorate · USPSMagnesium chlorate 5.1 UN2723 II 5A 5A
• Magnesium diamide · USPSMagnesium diamide 4.2 UN2004 II Prohibited Prohibited
• Magnesium dross, wet or hot · USPSMagnesium dross, wet or hot Forbidden Prohibited Prohibited Prohibited Prohibited
• Magnesium fluorosilicate · USPSMagnesium fluorosilicate 6.1 UN2853 III 6A 6A
• Magnesium granules, coated particle size not less than 149 microns · USPSMagnesium granules, coated particle size not less than 149 microns 4.3 UN2950 III Prohibited Prohibited
• Magnesium hydride · USPSMagnesium hydride 4.3 UN2010 I Prohibited Prohibited
• Magnesium nitrate · USPSMagnesium nitrate 5.1 UN1474 III 5A 5A
• Magnesium perchlorate · USPSMagnesium perchlorate 5.1 UN1475 II 5A 5A
• Magnesium peroxide · USPSMagnesium peroxide 5.1 UN1476 II 5A 5A
• Magnesium phosphide · USPSMagnesium phosphide 4.3 UN2011 I Prohibited Prohibited
• Magnesium, powder or Magnesium alloys, powder · USPSMagnesium, powder or Magnesium alloys, powder 4.3 UN1418 I Prohibited Prohibited
• Magnesium silicide · USPSMagnesium silicide 4.3 UN2624 II Prohibited Prohibited
• Magnetised material · Royal Mail Wholesale (Access customers)Magnetised material with a magnetic field strength of 0.159A/m or more at a distance of 2.1m from the outside of the package.
• Magnetised material (counter guidance threshold) · Royal Mail / ParcelforceMagnetised material (with a field strength of 0.418A/metre or more at a distance of 4.6 metres from the outside of the package)
• Magnetized materials — domestic surface transportation · USPSDomestic Mail via Surface Transportation: Magnetized materials are not regulated as hazardous when transported via surface transportation.
• Magnetized materials with field strength exceeding 0.00525 gauss at 15 feet · USPSMaterials with a field strength over 0.00525 gauss at 15 feet are nonmailable in domestic and international air transportation under any circumstances.
• Maleic anhydride · USPSMaleic anhydride 8 UN2215 III 8A 8A
• Maleic anhydride, molten · USPSMaleic anhydride, molten 8 UN2215 III Prohibited Prohibited
• Malononitrile · USPSMalononitrile 6.1 UN2647 II Prohibited Prohibited
• Maneb or Maneb preparations with not less than 60 percent maneb · USPSManeb or Maneb preparations with not less than 60 percent maneb 4.2 UN2210 III Prohibited Prohibited
• Maneb stabilized or Maneb preparations, stabilized against self- heating · USPSManeb stabilized or Maneb preparations, stabilized against self- heating 4.3 UN2968 III Prohibited Prohibited
• Manganese nitrate · USPSManganese nitrate 5.1 UN2724 III 5A 5A
• Manganese resinate · USPSManganese resinate 4.1 UN1330 III Prohibited 4A
• Mannitan tetranitrate · USPSMannitan tetranitrate Forbidden Prohibited Prohibited Prohibited Prohibited
• Mannitol hexanitrate (dry) · USPSMannitol hexanitrate (dry) Forbidden Prohibited Prohibited Prohibited Prohibited
• Marijuana · USPSMarijuana (medical or otherwise); hemp/CBD is allowed, but restricted
• Matches · Royal Mail / Post OfficeMatches (including safety matches and windproof matches) International – not allowed in the mail UK – not allowed in the mail
• Matches · Royal Mail Wholesale (Access customers)Matches Of any kind, including safety and windproof matches.
• Matches, fusee · USPSMatches, fusee 4.1 UN2254 III Prohibited Prohibited
• Matches, safety (book, card, or strike on box) · USPSMatches, safety (book, card, or strike on box) 4.1 UN1944 III Prohibited 4B
• Matches, strike anywhere · USPSMatches, strike anywhere 4.1 UN1331 III Prohibited Prohibited
• Matches, wax, Vesta · USPSMatches, wax, Vesta 4.1 UN1945 III Prohibited Prohibited
• Materials listed as 'Forbidden' in the Hazardous Materials Table · US DOT (49 CFR, all modes)A material for which the entry in this column is “Forbidden” may not be offered for transportation or transported. This prohibition does not apply if the material is diluted, stabi
• Materials requiring Associate Administrator approval (Special Provision 131) · US DOT (49 CFR, all modes)This material may not be offered for transportation unless approved by the Associate Administrator.
• Medical Devices · FedExMedical Devices – must verify that the accepting warehouse complies with state requirements/ licensing/permits for distribution of medical devices
• Medicine, liquid, flammable, toxic, n.o.s. · USPS · IIMedicine, liquid, flammable, toxic, n.o.s. 3 UN3248 II Prohibited Prohibited
• Medicine, liquid, flammable, toxic, n.o.s. · USPS · IIIMedicine, liquid, flammable, toxic, n.o.s. 3 UN3248 III Prohibited 3A
• Medicine, liquid, toxic, n.o.s. · USPSMedicine, liquid, toxic, n.o.s. 6.1 UN1851 II, III 6A 6A
• Medicine, solid, toxic, n.o.s. · USPSMedicine, solid, toxic, n.o.s. 6.1 UN3249 II, III 6A 6A
• Medicines & Prescription Drugs · USPSPrescription medications may only be mailed by Drug Enforcement Administration (DEA) registered distributors.
• Mercaptans, liquid, flammable, n.o.s. or Mercaptan mixture, liquid, flammable, n.o.s. · USPSMercaptans, liquid, flammable, n.o.s. or Mercaptan mixture, liquid, flammable, n.o.s. 3 UN3336 I, II, III Prohibited 3A
• Mercuric arsenate · USPSMercuric arsenate 6.1 UN1623 II Prohibited Prohibited
• Mercuric chloride · USPSMercuric chloride 6.1 UN1624 II Prohibited Prohibited
• Mercuric nitrate · USPSMercuric nitrate 6.1 UN1625 II Prohibited Prohibited
• Mercuric potassium cyanide · USPSMercuric potassium cyanide 6.1 UN1626 I Prohibited Prohibited
• Mercurous azide · USPSMercurous azide Forbidden Prohibited Prohibited Prohibited Prohibited
• Mercurous nitrate · USPSMercurous nitrate 6.1 UN1627 II Prohibited Prohibited
• Mercury · USPSLiquid mercury in any amount (and devices containing a visible amount of mercury) is prohibited from the US Mail, so you must find another carrier.
• Mercury acetate · USPSMercury acetate 6.1 UN1629 II Prohibited Prohibited
• Mercury acetylide · USPSMercury acetylide Forbidden Prohibited Prohibited Prohibited Prohibited
• Mercury ammonium chloride · USPSMercury ammonium chloride 6.1 UN1630 II Prohibited Prohibited
• Mercury and mercury-containing devices (UN2809) · USPSMercury and Mercury-Containing Devices (UN2809): Includes metallic mercury and items such as thermometers, barometers, and sphygmomanometers (i.e., blood pressure meters) that cont
• Mercury based pesticides, liquid, flammable, toxic, flashpoint less than 23° C · USPSMercury based pesticides, liquid, flammable, toxic, flashpoint less than 23° C 3 UN2778 I, II Prohibited Prohibited
• Mercury based pesticides, liquid, toxic · USPSMercury based pesticides, liquid, toxic 6.1 UN3012 I, II Prohibited Prohibited
• Mercury based pesticides, liquid, toxic, flammable, flashpoint not less than 23° C · USPS · I, IIMercury based pesticides, liquid, toxic, flammable, flashpoint not less than 23° C 6.1 UN3011 I, II Prohibited Prohibited
• Mercury based pesticides, liquid, toxic, flammable, flashpoint not less than 23° C · USPS · IIIMercury based pesticides, liquid, toxic, flammable, flashpoint not less than 23° C 6.1 UN3011 III 6A 6A
• Mercury based pesticides, solid, toxic · USPSMercury based pesticides, solid, toxic 6.1 UN2777 I, II Prohibited Prohibited
• Mercury benzoate · USPSMercury benzoate 6.1 UN1631 II Prohibited Prohibited
• Mercury bromides · USPSMercury bromides 6.1 UN1634 II Prohibited Prohibited
• Mercury compounds, liquid, n.o.s. · USPS · I, IIMercury compounds, liquid, n.o.s. 6.1 UN2024 I, II Prohibited Prohibited
• Mercury compounds, liquid, n.o.s. · USPS · IIIMercury compounds, liquid, n.o.s. 6.1 UN2024 III 6A 6A
• Mercury compounds, solid, n.o.s. · USPS · I, IIMercury compounds, solid, n.o.s. 6.1 UN2025 I, II Prohibited Prohibited
• Mercury compounds, solid, n.o.s. · USPS · IIIMercury compounds, solid, n.o.s. 6.1 UN2025 III 6A 6A
• Mercury contained in manufactured articles · USPSMercury contained in manufactured articles 8 UN3506 III 8C 8C
• Mercury cyanide · USPSMercury cyanide 6.1 UN1636 II Prohibited Prohibited
• Mercury gluconate · USPSMercury gluconate 6.1 UN1637 II Prohibited Prohibited
• Mercury iodide · USPSMercury iodide 6.1 UN1638 II Prohibited Prohibited
• Mercury iodide aquabasic ammonobasic (Iodide of Millon’s base) · USPSMercury iodide aquabasic ammonobasic (Iodide of Millon’s base) Forbidden Prohibited Prohibited Prohibited Prohibited
• Mercury nitride · USPSMercury nitride Forbidden Prohibited Prohibited Prohibited Prohibited
• Mercury nucleate · USPSMercury nucleate 6.1 UN1639 II Prohibited Prohibited
• Mercury oleate · USPSMercury oleate 6.1 UN1640 II Prohibited Prohibited
• Mercury oxide · USPSMercury oxide 6.1 UN1641 II Prohibited Prohibited
• Mercury oxycyanide · USPSMercury oxycyanide Forbidden Prohibited Prohibited Prohibited Prohibited
• Mercury oxycyanide, desensitized · USPSMercury oxycyanide, desensitized 6.1 UN1642 II Prohibited Prohibited
• Mercury potassium iodide · USPSMercury potassium iodide 6.1 UN1643 II Prohibited Prohibited
• Mercury salicylate · USPSMercury salicylate 6.1 UN1644 II Prohibited Prohibited
• Mercury sulfates · USPSMercury sulfates 6.1 UN1645 II Prohibited Prohibited
• Mercury thiocyanate · USPSMercury thiocyanate 6.1 UN1646 II Prohibited Prohibited
• Mercury Vapor Devices · USPSSome consumer devices, like compact fluorescent light bulbs, contain tiny amounts of mercury vapor. These items are restricted, but mailable.
• Mercurybasedpesticides,liquid, toxic · USPS · I, IIMercurybasedpesticides,liquid, toxic 6.1 UN3012 I, II Prohibited Prohibited
• Mercurybasedpesticides,liquid, toxic · USPS · IIIMercurybasedpesticides,liquid, toxic 6.1 UN3012 III 6A 6A
• Mercurybasedpesticides,solid, toxic · USPS · I, IIMercurybasedpesticides,solid, toxic 6.1 UN2777 I, II Prohibited Prohibited
• Mercurybasedpesticides,solid, toxic · USPS · IIIMercurybasedpesticides,solid, toxic 6.1 UN2777 III 6A 6A
• Mesityl oxide · USPSMesityl oxide 3 UN1229 III Prohibited Prohibited
• Metal carbonyls, liquid, n.o.s. · USPS · I, IIMetal carbonyls, liquid, n.o.s. 6.1 UN3281 I, II Prohibited Prohibited
• Metal carbonyls, liquid, n.o.s. · USPS · IIIMetal carbonyls, liquid, n.o.s. 6.1 UN3281 III 6A 6A
• Metal carbonyls, solid, n.o.s. · USPS · I, IIMetal carbonyls, solid, n.o.s. 6.1 UN3466 I, II Prohibited Prohibited
• Metal carbonyls, solid, n.o.s. · USPS · IIIMetal carbonyls, solid, n.o.s. 6.1 UN3466 III 6A 6A
• Metal catalyst, dry · USPS · I, IIMetal catalyst, dry 4.2 UN2881 I, II Prohibited Prohibited
• Metal catalyst, dry · USPS · IIIMetal catalyst, dry 4.2 UN2881 III Prohibited 4A
• Metal catalyst, wetted with a visible excess of liquid · USPSMetal catalyst, wetted with a visible excess of liquid 4.2 UN1378 II Prohibited Prohibited
• Metal hydrides, flammable, n.o.s. · USPSMetal hydrides, flammable, n.o.s. 4.1 UN3182 II, III Prohibited 3A
• Metal hydrides, water reactive, n.o.s. · USPSMetal hydrides, water reactive, n.o.s. 4.3 UN1409 I Prohibited Prohibited
• Metal powder, self-heating, n.o.s. · USPSMetal powder, self-heating, n.o.s. 4.2 UN3189 II, III Prohibited Prohibited
• Metal powders, flammable, n.o.s. · USPSMetal powders, flammable, n.o.s. 4.1 UN3089 II, III Prohibited 4A
• Metal salts of methyl nitramine (dry) · USPSMetal salts of methyl nitramine (dry) Forbidden Prohibited Prohibited Prohibited Prohibited
• Metal salts of organic compounds, flammable, n.o.s. · USPSMetal salts of organic compounds, flammable, n.o.s. 4.1 UN3181 II, III Prohibited 4A
• Metaldehyde · USPSMetaldehyde 4.1 UN1332 III Prohibited 4A
• Metallic substance, water reactive, self-heating, n.o.s. · USPSMetallic substance, water reactive, self-heating, n.o.s. 4.3 UN3209 I, II, III Prohibited Prohibited
• Metallic substances, water reactive, n.o.s. · USPSMetallic substances, water reactive, n.o.s. 4.3 UN3208 I, II, III Prohibited Prohibited
• Methacrylaldehyde, inhibited · USPSMethacrylaldehyde, inhibited 3 UN2396 II Prohibited Prohibited
• Methacrylic acid, inhibited · USPSMethacrylic acid, inhibited 8 UN2531 III 8A 8A
• Methacrylonitrile, inhibited · USPSMethacrylonitrile, inhibited 3 UN3079 I Prohibited Prohibited
• Methallyl alcohol · USPSMethallyl alcohol 3 UN2614 III Prohibited 3A
• Methane, compressed or Natural gas, compressed (with high methane content) · USPSMethane, compressed or Natural gas, compressed (with high methane content) 2.1 UN1971 n/a Prohibited 2A
• Methanesulfonyl chloride · USPSMethanesulfonyl chloride 6.1 UN3246 I Prohibited Prohibited
• Methanol · USPSMethanol 3 UN1230 II Prohibited 3A
• Methazoic acid · USPSMethazoic acid Forbidden Prohibited Prohibited Prohibited Prohibited
• Methoxymethyl isocyanate · USPSMethoxymethyl isocyanate 6.1 UN2605 I Prohibited Prohibited
• Methyl-2-chloropropionate · USPSMethyl-2-chloropropionate 3 UN2933 III Prohibited 3A
• Methyl acetate · USPSMethyl acetate 3 UN1231 II Prohibited 3A
• Methyl acetylene and propadiene mixtures, stabilized · USPSMethyl acetylene and propadiene mixtures, stabilized 2.1 UN1060 n/a Prohibited 2A
• Methyl acrylate, stabilized · USPSMethyl acrylate, stabilized 3 UN1919 II Prohibited 3A
• Methyl allyl chloride · USPSMethyl allyl chloride 3 UN2554 II Prohibited 3A
• Methyl bromide · USPSMethyl bromide 2.3 UN1062 n/a Prohibited Prohibited
• Methyl bromide and ethylene dibromide mixtures, liquid · USPSMethyl bromide and ethylene dibromide mixtures, liquid 6.1 UN1647 I Prohibited Prohibited
• Methyl bromoacetate · USPSMethyl bromoacetate 6.1 UN2643 II Prohibited Prohibited
• Methyl butyrate · USPSMethyl butyrate 3 UN1237 II Prohibited 3A
• Methyl chloride and methylene chloride mixtures · USPSMethyl chloride and methylene chloride mixtures 2.1 UN1912 n/a Prohibited 2A
• Methyl chloride, or Refrigerant gas R 40 · USPSMethyl chloride, or Refrigerant gas R 40 2.1 UN1063 Prohibited 2A
• Methyl chloroacetate · USPSMethyl chloroacetate 6.1 UN2295 I Prohibited Prohibited
• Methyl chloroformate · USPSMethyl chloroformate 6.1 UN1238 I Prohibited Prohibited
• Methyl chloromethyl ether · USPSMethyl chloromethyl ether 6.1 UN1239 I Prohibited Prohibited
• Methyl dichloroacetate · USPSMethyl dichloroacetate 6.1 UN2299 III 6A 6A
• Methyl fluoride, or Refrigerant gas R 41 · USPSMethyl fluoride, or Refrigerant gas R 41 2.1 UN2454 n/a Prohibited 2A
• Methyl formate · USPSMethyl formate 3 UN1243 I Prohibited 3A
• Methyl iodide · USPSMethyl iodide 6.1 UN2644 I Prohibited Prohibited
• Methyl isobutyl carbinol · USPSMethyl isobutyl carbinol 3 UN2053 III Prohibited 3A
• Methyl isobutyl ketone · USPSMethyl isobutyl ketone 3 UN1245 II Prohibited 3A
• Methyl isocyanate · USPSMethyl isocyanate 6.1 UN2480 I Prohibited Prohibited
• Methyl isopropenyl ketone, inhibited · USPSMethyl isopropenyl ketone, inhibited 3 UN1246 II Prohibited 3A
• Methyl isothiocyanate · USPSMethyl isothiocyanate 6.1 UN2477 I Prohibited Prohibited
• Methyl isovalerate · USPSMethyl isovalerate 3 UN2400 II Prohibited 3A
• Methyl magnesium bromide, in ethyl ether · USPSMethyl magnesium bromide, in ethyl ether 4.3 UN1928 I Prohibited Prohibited
• Methyl mercaptan · USPSMethyl mercaptan 2.3 UN1064 n/a Prohibited Prohibited
• Methyl methacrylate monomer, stabilized · USPSMethyl methacrylate monomer, stabilized 3 UN1247 II Prohibited 3A
• Methyl nitramine (dry) · USPSMethyl nitramine (dry) Forbidden Prohibited Prohibited Prohibited Prohibited
• Methyl nitrate · USPSMethyl nitrate Forbidden Prohibited Prohibited Prohibited Prohibited
• Methyl nitrite · USPSMethyl nitrite Forbidden Prohibited Prohibited Prohibited Prohibited
• Methyl orthosilicate · USPSMethyl orthosilicate 6.1 UN2606 I Prohibited Prohibited
• Methyl phosphonic dichloride · USPSMethyl phosphonic dichloride 6.1 NA9206 I Prohibited Prohibited
• Methyl phosphonous dichloride, pyrophoric liquid · USPSMethyl phosphonous dichloride, pyrophoric liquid 6.1 NA2845 I Prohibited Prohibited
• Methyl picric acid (heavy metal salts of) · USPSMethyl picric acid (heavy metal salts of) Forbidden Prohibited Prohibited Prohibited Prohibited
• Methyl propionate · USPSMethyl propionate 3 UN1248 II Prohibited 3A
• Methyl propyl ether · USPSMethyl propyl ether 3 UN2612 II Prohibited 3A
• Methyl propyl ketone · USPSMethyl propyl ketone 3 UN1249 II Prohibited 3A
• Methyl tertbutyl ether · USPSMethyl tertbutyl ether 3 UN2398 II Prohibited 3A
• Methyl trichloroacetate · USPSMethyl trichloroacetate 6.1 UN2533 III 6A 6A
• Methyl trimethylol methane trinitrate · USPSMethyl trimethylol methane trinitrate Forbidden Prohibited Prohibited Prohibited Prohibited
• Methyl vinyl ketone, stabilized · USPSMethyl vinyl ketone, stabilized 6.1 UN1251 I Prohibited Prohibited
• Methylal · USPSMethylal 3 UN1234 II Prohibited Prohibited
• Methylamine, anhydrous · USPSMethylamine, anhydrous 2.1 UN1061 n/a Prohibited 2A
• Methylamine, aqueous solution · USPSMethylamine, aqueous solution 3 UN1235 II Prohibited 3A
• Methylamine dinitramine and dry salts thereof · USPSMethylaminedinitramineanddrysalts thereof Forbidden Prohibited Prohibited Prohibited Prohibited
• Methylamine nitroform · USPSMethylamine nitroform Forbidden Prohibited Prohibited Prohibited Prohibited
• Methylamine perchlorate (dry) · USPSMethylamine perchlorate (dry) Forbidden Prohibited Prohibited Prohibited Prohibited
• Methylaminedinitramineanddrysalts thereof · USPSMethylaminedinitramineanddrysalts thereof Forbidden Prohibited Prohibited Prohibited Prohibited
• Methylamyl acetate · USPSMethylamyl acetate 3 UN1233 III Prohibited 3A
• Methylchlorosilane · USPSMethylchlorosilane 2.3 UN2534 n/a Prohibited Prohibited
• Methylcyclohexane · USPSMethylcyclohexane 3 UN2296 II Prohibited 3A
• Methylcyclohexanols, flammable · USPSMethylcyclohexanols, flammable 3 UN2617 III Prohibited 3A
• Methylcyclohexanone · USPSMethylcyclohexanone 3 UN2297 III Prohibited 3A
• Methylcyclopentane · USPSMethylcyclopentane 3 UN2298 II Prohibited 3A
• Methyldichloroarsine · USPSMethyldichloroarsine 6.1 NA1556 I Prohibited Prohibited
• Methyldichlorosilane · USPSMethyldichlorosilane 4.3 UN1242 I Prohibited Prohibited
• Methylene glycol dinitrate · USPSMethylene glycol dinitrate Forbidden Prohibited Prohibited Prohibited Prohibited
• Methylhydrazine · USPSMethylhydrazine 6.1 UN1244 I Prohibited Prohibited
• Methylpentadienes · USPSMethylpentadienes 3 UN2461 II Prohibited 3A
• Methylphenyldichlorosilane · USPSMethylphenyldichlorosilane 8 UN2437 II 8A 8A
• Methyltetrahydrofuran · USPSMethyltetrahydrofuran 3 UN2536 II Prohibited 3A
• Methyltrichlorosilane · USPSMethyltrichlorosilane 3 UN1250 I Prohibited Prohibited
• Mines with bursting charge · USPSMines with bursting charge 1.1D UN0137 II Prohibited Prohibited
• Miscellaneous hazardous materials (Hazard Class 9) — international mail · USPSInternational Mail: All miscellaneous hazardous materials are prohibited, except for certain magnetized materials as permitted in 349.242 (a) and IMM 136.1g, and small consumer-typ
• Misleading endorsements · Royal Mail / ParcelforceMisleading Endorsements - Items must not bear words, marks or designs which are unauthorized and which may reasonably lead the recipient to believe that the parcel has been sent by
• Model fuel for glow-plug engines · USPSModel Fuel (for Glow-Plug Engines): A flammable liquid with a flashpoint ranging from 65° F to 75° F. It is mailable only if it qualifies as a Limited Quantity surface material
• Model rocket motor · USPSModel rocket motor 1.4C NA0276 II Prohibited Prohibited
• Molybdenum pentachloride · USPSMolybdenum pentachloride 8 UN2508 III 8A 8A
• Monochloroacetone (unstabilized) · USPSMonochloroacetone (unstabilized) Forbidden Prohibited Prohibited Prohibited Prohibited
• Morpholine · USPSMorpholine 3 UN2054 III Prohibited 3A
• Motor fuel anti-knock mixture, flammable · USPSMotor fuel anti-knock mixture, flammable 6.1 UN3483 I Prohibited Prohibited
• Motor fuel anti-knock mixtures · USPSMotor fuel anti-knock mixtures 6.1 UN1649 I Prohibited Prohibited
• N-Aminoethylpiperazine · USPSN-Aminoethylpiperazine 8 UN2815 III 8A 8A
• n-Amyl methyl ketone · USPSn-Amyl methyl ketone 3 UN1110 III Prohibited 3A
• n-Butyl chloroformate · USPSn-Butyl chloroformate 6.1 UN2743 I Prohibited Prohibited
• n-Butyl formate · USPSn-Butyl formate 3 UN1128 II Prohibited 3A
• n-Butyl isocyanate · USPSn-Butyl isocyanate 6.1 UN2485 I Prohibited Prohibited
• n-Butyl methacrylate, stabilized · USPSn-Butyl methacrylate, stabilized 3 UN2227 III Prohibited 3A
• n-Butyl peroxydicarbonate, with more than 52 percent in solution · USPSn-Butylperoxydicarbonate,withmore than 52 percent in solution Forbidden Prohibited Prohibited Prohibited Prohibited
• n-Butylamine · USPSn-Butylamine 3 UN1125 II Prohibited Prohibited
• N-Butylaniline · USPSN-Butylaniline 6.1 UN2378 II Prohibited Prohibited
• n-Butylperoxydicarbonate,withmore than 52 percent in solution · USPSn-Butylperoxydicarbonate,withmore than 52 percent in solution Forbidden Prohibited Prohibited Prohibited Prohibited
• n-Decane · USPSn-Decane 3 UN2247 III Prohibited 3A
• N-Ethyl-N-benzylaniline · USPSN-Ethyl-N-benzylaniline 6.1 UN2274 III 6A 6A
• N-Ethylaniline · USPSN-Ethylaniline 6.1 UN2272 III 6A 6A
• N-Ethylbenzyltoluidines liquid · USPSN-Ethylbenzyltoluidines liquid 6.1 UN2753 III 6A 6A
• N-Ethylbenzyltoluidines, solid · USPSN-Ethylbenzyltoluidines, solid 6.1 UN3460 III 6A 6A
• N-Ethyltoluidines · USPSN-Ethyltoluidines 6.1 UN2754 II Prohibited Prohibited
• n-Heptaldehyde · USPSn-Heptaldehyde 3 UN3056 III Prohibited 3A
• n-Heptane · USPSn-Heptane 3 UN2278 II Prohibited 3A
• N-Methylaniline · USPSN-Methylaniline 6.1 UN2294 III 6A 6A
• N-Methylbutylamine · USPSN-Methylbutylamine 3 UN2945 II Prohibited Prohibited
• N-n-Butyl imidazole · USPSN-n-Butyl imidazole 6.1 UN2690 II Prohibited Prohibited
• N,N’-Dichlorazodicarbonamidine (salts of) (dry) · USPSN,N’-Dichlorazodicarbonamidine (salts of) (dry) Forbidden Prohibited Prohibited Prohibited Prohibited
• N,N-Diethylaniline · USPSN,N-Diethylaniline 6.1 UN2432 III 6A 6A
• N,N-Diethylethylenediamine · USPSN,N-Diethylethylenediamine 8 UN2685 II Prohibited Prohibited
• N,N-Dimethylaniline · USPSN,N-Dimethylaniline 6.1 UN2253 II Prohibited Prohibited
• N,N-Dimethylcyclohexlamine · USPSN,N-Dimethylcyclohexlamine 8 UN2264 II 8A 8A
• N,N-Dimethylformamide · USPSN,N-Dimethylformamide 3 UN2265 III Prohibited 3A
• N,N’-(hexanitrodiphenyl) ethylene dinitramine (dry) · USPSN,N’-(hexanitrodiphenyl) ethylene dinitramine (dry) Forbidden Prohibited Prohibited Prohibited Prohibited
• N-Nitro-N-methylglycolamide nitrate · USPSN-Nitro-N-methylglycolamide nitrate Forbidden Prohibited Prohibited Prohibited Prohibited
• N-Nitroaniline · USPSN-Nitroaniline Forbidden Prohibited Prohibited Prohibited Prohibited
• n-Propanol or Propyl alcohol, normal · USPSn-Propanol or Propyl alcohol, normal 3 UN1274 II, III Prohibited 3A
• n-Propyl acetate · USPSn-Propyl acetate 3 UN1276 II Prohibited 3A
• n-Propyl benzene · USPSn-Propyl benzene 3 UN2364 III Prohibited 3A
• n-Propyl chloroformate · USPSn-Propyl chloroformate 6.1 UN2740 I Prohibited Prohibited
• n-Propyl nitrate · USPSn-Propyl nitrate 3 UN1865 II Prohibited 3A
• Nail Polish · USPSIf the nail polish you want to mail is flammable, you are responsible for knowing its flashpoint and toxicity. Flammable nail polishes may be mailed domestically if they are a cons
• Nail varnish, polish or gel · Royal Mail / Post OfficeNail varnish, polish or gel (solvent and water-based) International – not allowed in the mail UK – allowed in the mail, see restrictions and packaging guidelines below: Volume per
• Nail varnish, polish or gel (counter guidance) · Royal Mail / ParcelforceNail varnish, polish or gel Packaging guidelines: Volume per item must not exceed 30ml. No more than four items in any one parcel.
• Naphthalene, crude or Naphthalene, refined · USPSNaphthalene, crude or Naphthalene, refined 4.1 UN1334 III Prohibited 4A
• Naphthalene diozonide · USPSNaphthalene diozonide Forbidden Prohibited Prohibited Prohibited Prohibited
• Naphthalene, molten · USPSNaphthalene, molten 4.1 UN2304 III Prohibited 4A
• Naphthylamineperchlorate · USPSNaphthylamineperchlorate Forbidden Prohibited Prohibited Prohibited Prohibited
• Naphthylthiourea · USPSNaphthylthiourea 6.1 UN1651 II Prohibited Prohibited
• Naphthylurea · USPSNaphthylurea 6.1 UN1652 II Prohibited Prohibited
• Neon, compressed · USPSNeon, compressed 2.2 UN1065 n/a 2B 2B
• Neon, refrigerated liquid (cryogenic liquid) · USPSNeon, refrigerated liquid (cryogenic liquid) 2.2 UN1913 n/a Prohibited Prohibited
• New wet, non-spillable batteries (sealed lead acid, absorbed glass mat, gel cell) · Royal Mail / ParcelforcePackaging guidelines: No more than one battery in any one parcel. Maximum weight 1.5kg. Item must be protected against short circuit (by insulation of exposed terminals) and secure
• Nickel cyanide · USPSNickel cyanide 6.1 UN1653 II Prohibited Prohibited
• Nickel nitrate · USPSNickel nitrate 5.1 UN2725 III 5A 5A
• Nickel nitrite · USPSNickel nitrite 5.1 UN2726 III 5A 5A
• Nickel picrate · USPSNickel picrate Forbidden Prohibited Prohibited Prohibited Prohibited
• Nicotine · USPSNicotine 6.1 UN1654 II Prohibited Prohibited
• Nicotine compounds, liquid, n.o.s. or Nicotine preparations, liquid, n.o.s. · USPS · I, IINicotine compounds, liquid, n.o.s. or Nicotine preparations, liquid, n.o.s. 6.1 UN3144 I, II Prohibited Prohibited
• Nicotine compounds, liquid, n.o.s. or Nicotine preparations, liquid, n.o.s. · USPS · IIINicotine compounds, liquid, n.o.s. or Nicotine preparations, liquid, n.o.s. 6.1 UN3144 III 6A 6A
• Nicotine compounds, solid, n.o.s. or Nicotine preparations, solid, n.o.s. · USPS · I, IINicotine compounds, solid, n.o.s. or Nicotine preparations, solid, n.o.s. 6.1 UN1655 I, II Prohibited Prohibited
• Nicotine compounds, solid, n.o.s. or Nicotine preparations, solid, n.o.s. · USPS · IIINicotine compounds, solid, n.o.s. or Nicotine preparations, solid, n.o.s. 6.1 UN1655 III 6A 6A
• Nicotine hydrochloride liquid or solution · USPSNicotine hydrochloride liquid or solution 6.1 UN1656 II Prohibited Prohibited
• Nicotine hydrochloride, solid · USPSNicotine hydrochloride, solid 6.1 UN3444 II Prohibited Prohibited
• Nicotine salicylate · USPSNicotine salicylate 6.1 UN1657 II Prohibited Prohibited
• Nicotine sulfate, solid · USPSNicotine sulfate, solid 6.1 UN3445 II Prohibited Prohibited
• Nicotine sulfate, solution · USPSNicotine sulfate, solution 6.1 UN1658 II Prohibited Prohibited
• Nicotine tartrate · USPSNicotine tartrate 6.1 UN1659 II Prohibited Prohibited
• Nitophenols (o-; m-; p-;) · USPSNitophenols (o-; m-; p-;) 6.1 UN1663 III 6A 6A
• Nitrated paper (unstable) · USPSNitrated paper (unstable) Forbidden Prohibited Prohibited Prohibited Prohibited
• Nitrates, inorganic, aqueous solution, n.o.s. · USPSNitrates, inorganic, aqueous solution, n.o.s. 5.1 UN3218 II, III 5A 5A
• Nitrates, inorganic, n.o.s. · USPSNitrates, inorganic, n.o.s. 5.1 UN1477 II, III 5A 5A
• Nitrates of diazonium compounds · USPSNitrates of diazonium compounds Forbidden Prohibited Prohibited Prohibited Prohibited
• Nitrating acid mixtures, spent with more than 50 percent nitric acid · USPSNitrating acid mixtures, spent with more than 50 percent nitric acid 8 UN1826 I Prohibited Prohibited
• Nitrating acid mixtures, spent with not more than 50 percent nitric acid · USPSNitrating acid mixtures, spent with not more than 50 percent nitric acid 8 UN1826 II Prohibited Prohibited
• Nitrating acid mixtures, with more than 50 percent nitric acid · USPSNitrating acid mixtures, with more than 50 percent nitric acid 8 UN1796 I Prohibited Prohibited
• Nitrating acid mixtures, with not more than 50 percent nitric acid · USPSNitrating acid mixtures, with not more than 50 percent nitric acid 8 UN1796 II Prohibited Prohibited
• Nitric acid other than red fuming, with more than 70 percent nitric acid · USPSNitric acid other than red fuming, with more than 70 percent nitric acid 8 UN2031 I Prohibited Prohibited
• Nitric acid other than red fuming, with not more than 70 percent nitric acid · USPSNitric acid other than red fuming, with not more than 70 percent nitric acid 8 UN2031 II Prohibited Prohibited
• Nitric acid, red fuming · USPSNitric acid, red fuming 8 UN2032 I Prohibited Prohibited
• Nitric acid (UN2031, UN2032) · USPSNitric Acid (UN2031, UN2032).
• Nitric oxide, compressed · USPSNitric oxide, compressed 2.3 UN1660 n/a Prohibited Prohibited
• Nitriles, flammable, toxic, n.o.s. · USPSNitriles, flammable, toxic, n.o.s. 3 UN3273 I, II Prohibited Prohibited
• Nitriles, toxic, flammable, n.o.s. · USPSNitriles, toxic, flammable, n.o.s. 6.1 UN3275 I, II Prohibited Prohibited
• Nitriles, toxic, liquid, n.o.s. · USPS · I, IINitriles, toxic, liquid, n.o.s. 6.1 UN3276 I, II Prohibited Prohibited
• Nitriles, toxic, liquid, n.o.s. · USPS · IIINitriles, toxic, liquid, n.o.s. 6.1 UN3276 III 6A 6A
• Nitriles, toxic, solid, n.o.s. · USPS · I, II,Nitriles, toxic, solid, n.o.s. 6.1 UN3439 I, II, Prohibited Prohibited
• Nitriles, toxic, solid, n.o.s. · USPS · IIINitriles, toxic, solid, n.o.s. 6.1 UN3439 III 6A 6A
• Nitrites, inorganic, aqueous solution, n.o.s. · USPSNitrites, inorganic, aqueous solution, n.o.s. 5.1 UN3219 II, III 5A 5A
• Nitrites, inorganic, n.o.s. · USPSNitrites, inorganic, n.o.s. 5.1 UN2627 II 5A 5A
• Nitro isobutane triol trinitrate · USPSNitro isobutane triol trinitrate Forbidden Prohibited Prohibited
• Nitro urea · USPSNitro urea 1.1D UN0147 II Prohibited Prohibited
• Nitroanisole, solid · USPSNitroanisole, solid 6.1 UN3458 III 6A 6A
• Nitrobenzene · USPSNitrobenzene 6.1 UN1662 II Prohibited Prohibited
• Nitrobenzenesulfonic acid · USPSNitrobenzenesulfonic acid 8 UN2305 II 8A 8A
• Nitrobenzotrifluorides, liquid · USPSNitrobenzotrifluorides, liquid 6.1 UN2306 II Prohibited Prohibited
• Nitrobenzotrifluorides, solid · USPSNitrobenzotrifluorides, solid 6.1 UN3431 II Prohibited Prohibited
• Nitrobromobenzenes liquid · USPSNitrobromobenzenes liquid 6.1 UN2732 III 6A 6A
• Nitrobromobenzenes solid · USPSNitrobromobenzenes solid 6.1 UN3459 III 6A 6A
• Nitrocellulose, dry or wetted with less than 25 percent water (or alcohol), by mass · USPSNitrocellulose, dry or wetted with less than 25 percent water (or alcohol), by mass 1.1D UN0340 II Prohibited Prohibited
• Nitrocellulose, wetted with not less than 25 percent alcohol, by mass · USPSNitrocellulose, wetted with not less than 25 percent alcohol, by mass 1.3C UN0342 II Prohibited Prohibited
• Nitrocellulose with water with not less than 25 percent water, by mass · USPSNitrocellulose with water with not less than 25 percent water, by mass 4.1 UN2555 II Prohibited 4A
• Nitrocresols, liquid · USPSNitrocresols, liquid 6.1 UN3434 III 6A 6A
• Nitrocresols, solid · USPSNitrocresols, solid 6.1 UN2446 III 6A 6A
• Nitroethane · USPSNitroethane 3 UN2842 III Prohibited 3A
• Nitroethyl nitrate · USPSNitroethyl nitrate Forbidden Prohibited Prohibited Prohibited Prohibited
• Nitroethylene polymer · USPSNitroethylene polymer Forbidden Prohibited Prohibited Prohibited Prohibited
• Nitrogen, compressed · USPSNitrogen, compressed 2.2 UN1066 n/a 2B 2B
• Nitrogen, refrigerated liquid cryogenic liquid · USPSNitrogen, refrigerated liquid cryogenic liquid 2.2 UN1977 n/a Prohibited Prohibited
• Nitrogen trichloride · USPSNitrogen trichloride Forbidden Prohibited Prohibited Prohibited Prohibited
• Nitrogen trifluoride, · USPSNitrogen trifluoride, 2.2 UN2451 n/a Prohibited Prohibited
• Nitrogen triiodide · USPSNitrogen triiodide Forbidden Prohibited Prohibited Prohibited Prohibited
• Nitrogen triiodide monoamine · USPSNitrogen triiodide monoamine Forbidden Prohibited Prohibited Prohibited Prohibited
• Nitrogen trioxide · USPSNitrogen trioxide 2.3 UN2421 n/a Prohibited Prohibited
• Nitroglycerin, liquid, not desensitized · USPSNitroglycerin, liquid, not desensitized Forbidden Prohibited Prohibited Prohibited Prohibited
• Nitroglycerin, solution in alcohol, with not more than 1 percent nitroglycerin · USPSNitroglycerin, solution in alcohol, with not more than 1 percent nitroglycerin 3 UN1204 II Prohibited Prohibited
• Nitroguanidine nitrate · USPSNitroguanidine nitrate Forbidden Prohibited Prohibited Prohibited Prohibited
• Nitroguanidine or Picrite, dry or wetted with less than 20 percent water, by mass · USPSNitroguanidine or Picrite, dry or wetted with less than 20 percent water, by mass 1.1D UN0282 II Prohibited Prohibited
• Nitrohydrochloric acid · USPSNitrohydrochloric acid 8 UN1798 I Prohibited Prohibited
• Nitromannite (dry) · USPSNitromannite (dry) Forbidden Prohibited Prohibited Prohibited Prohibited
• Nitromethane · USPSNitromethane 3 UN1261 II Prohibited 3A
• Nitronaphthalene · USPSNitronaphthalene 4.1 UN2538 III Prohibited 4A
• Nitropropanes · USPSNitropropanes 3 UN2608 III Prohibited 3A
• Nitrostarch, dry or wetted with less than 20 percent water, by mass · USPSNitrostarch, dry or wetted with less than 20 percent water, by mass 1.1D UN0146 II Prohibited Prohibited
• Nitrostarch, wetted with not less than 20 percent water, by mass · USPSNitrostarch, wetted with not less than 20 percent water, by mass 4.1 UN1337 I Prohibited Prohibited
• Nitrosugars (dry) · USPSNitrosugars (dry) Forbidden Prohibited Prohibited Prohibited Prohibited
• Nitrosyl chloride · USPSNitrosyl chloride 2.3 UN1069 n/a Prohibited Prohibited
• Nitrosylsulfuric acid, liquid · USPSNitrosylsulfuric acid, liquid 8 UN2308 II 8A 8A
• Nitrosylsulfuric acid, solid · USPSNitrosylsulfuric acid, solid 8 UN3456 II 8A 8A
• Nitrotoluenes, liquid · USPSNitrotoluenes, liquid 6.1 UN1664 II Prohibited Prohibited
• Nitrotoluenes, solid · USPSNitrotoluenes, solid 6.1 UN3446 II Prohibited Prohibited
• Nitrotoluidines (mono) · USPSNitrotoluidines (mono) 6.1 UN2660 III 6A 6A
• Nitrotriazolone or NTO · USPSNitrotriazolone or NTO 1.1D UN0490 II Prohibited Prohibited
• Nitrous oxide · USPSNitrous oxide 2.2 UN1070 n/a 2B 2B
• Nitrous oxide, refrigerated liquid · USPSNitrous oxide, refrigerated liquid 2.2 UN2201 n/a Prohibited Prohibited
• Nitroxylenes, liquid · USPSNitroxylenes, liquid 6.1 UN1665 II Prohibited Prohibited
• Nitroxylenes, solid · USPSNitroxylenes, solid 6.1 UN3447 II Prohibited Prohibited
• Nonanes · USPSNonanes 3 UN1920 III Prohibited 3A
• nonhazardous liquids · USPSLiquids that are nonhazardous (i.e., not regulated as hazardous materials) are mailable provided they are properly packaged as specified in 451.3
• nonnarcotic prescription medicines · USPSOnly a pharmacists, medical practitioners, or other authorized dispensers may mail nonnarcotic prescription medications to patients under their care.
• nonprescription medicines (OTC drugs) · USPSOver-the-Counter (OTC) Drugs: Medicines that can be obtained without a prescription, such as patent medicines, aspirin, antiseptics, cold remedies, diet pills, and cosmetic medicin
• Nonspillable wet batteries (UN2800) · USPSNonspillable Wet Batteries (UN2800): Acceptable if completely sealed to prevent the liquid corrosive from spilling during handling
• Nonyltrichlorosilane · USPSNonyltrichlorosilane 8 UN1799 II Prohibited Prohibited
• o-Dichlorobenzene · USPSo-Dichlorobenzene 6.1 UN1591 III 6A 6A
• Obscene publications and unlawful indecent images · Royal Mail / Post OfficeObscene publications and unlawful indecent images Including obscene or extreme pornography as detailed in Part 5 of the Criminal Justice and Immigration Act 2008, and indecent phot
• Obscene publications and unlawful indecent images · Royal Mail Wholesale (Access customers)Including obscene or extreme pornography as detailed in Part 5 of the Criminal Justice and Immigration Act 2008 and indecent photographs or pseudo-photographs of a child as detaile
• Octadecyltrichlorosilane · USPSOctadecyltrichlorosilane 8 UN1800 II Prohibited Prohibited
• Octadiene · USPSOctadiene 3 UN2309 II Prohibited 3A
• Octafluorobut-2-ene or Refrigerant gas R 1318 · USPSOctafluorobut-2-ene or Refrigerant gas R 1318 2.2 UN2422 n/a Prohibited Prohibited
• Octafluorocyclobutane, or Refrigerant gas RC 318 · USPSOctafluorocyclobutane, or Refrigerant gas RC 318 2.2 UN1976 n/a Prohibited Prohibited
• Octafluoropropane or Refrigerant gas R 218 · USPSOctafluoropropane or Refrigerant gas R 218 2.2 UN2424 n/a Prohibited Prohibited
• Octanes · USPSOctanes 3 UN1262 II Prohibited 3A
• Octolite or Octol, dry or wetted with less than 15 percent water, by mass · USPSOctolite or Octol, dry or wetted with less than 15 percent water, by mass 1.1D UN0266 II Prohibited Prohibited
• Octonal · USPSOctonal 1.1D UN0496 n/a Prohibited Prohibited
• Octyl aldehydes · USPSOctyl aldehydes 3 UN1191 III Prohibited 3A
• Octyltrichlorosilane · USPSOctyltrichlorosilane 8 UN1801 II Prohibited Prohibited
• odor-producing materials · USPSAny matter that is a source of an obnoxious odor is nonmailable.
• Oil gas, compressed · USPSOil gas, compressed 2.3 UN1071 n/a Prohibited Prohibited
• One-of-a-kind/irreplaceable articles such as artwork valued over US$500,000 each · FedExOne-of-a-kind/irreplaceable articles such as artwork valued over US$500,000 each
• Organic peroxide, type A, liquid or solid · USPSOrganic peroxide, type A, liquid or solid Forbidden Prohibited Prohibited Prohibited Prohibited

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