UN1950 aerosols decoder.

The UN1950 row in the Hazardous Materials Table

The table below is 49 CFR 172.101 as published in the eCFR, current through October 29, 2026, for UN1950. Columns are: class (3), packing group (5), label codes (6), special provisions (7), packaging exceptions (8A), non-bulk packaging (8B), bulk packaging (8C), quantity limits for passenger aircraft or railcar (9A) and cargo aircraft only (9B), and vessel stowage (10A and 10B). UN1950 has 5 rows, so each one is listed.

Reading the packaging columns

Columns 8A to 8C do not hold rules themselves; they point to sections of part 173. For this entry they point to:

• 173.306: Limited quantities of compressed gases.
• 173.304: referenced in the table (section not read for this page).

Exceptions in column 8A apply only if that section is referenced for the specific material in the table, so a limited quantity route that exists for one UN number is not automatically open to another.

Special provisions on this entry

The letter prefixes on special provisions tell you where each applies (172.102(c)): a code of only numbers is multi-modal; "A" applies only to transportation by aircraft; "B" only to bulk packaging; "IB" and "IP" only to IBCs; "N" only to non-bulk packaging; "T" and "TP" only to UN portable tanks.

• A34: Aerosols containing a corrosive liquid in Packing Group II charged with a gas are not permitted for transportation by aircraft.
• N82: Points to 173.115 for the classification criteria for flammable aerosols.

Five rows, five different aircraft answers

Limits are in kilograms, not liters, and they differ by variant. Flammable and non-flammable aerosols show 75 kg on passenger aircraft and 150 kg on cargo aircraft only. Flammable aerosols that are engine starting fluid show Forbidden for passenger aircraft and 150 kg on cargo aircraft, and carry packaging 306 plus 304. Poison (Packing Group III) aerosols are Forbidden on both. Corrosive aerosols carry special provision A34: aerosols containing a corrosive liquid in Packing Group II charged with a gas are not permitted for transportation by aircraft.

What each can must meet: 173.306

Column 8A for all five rows is 306, the limited quantities of compressed gases section. For a metal aerosol container under 173.306(a)(3) the capacity of the container must not exceed 1 L (61.0 cubic inches), and the pressure conditions follow the table of authorized metal aerosol containers by gauge pressure at 54.4 degrees C (130 degrees F). Limited quantities that conform are excepted from labeling unless transported by aircraft and from specification packaging; packages are marked per 172.315 and are not subject to the placarding subpart. Special provision N82 on flammable rows sends the flammability test to 173.115.

Vessel stowage and disposal shipments

Every row shows stowage category A with provisions 25, 87, 126 and 157. Code 25 means protected from sources of heat, 87 means stow separated from Class 1 (explosives) except Division 1.4, 126 means segregation same as for Class 9, and 157 says aerosols and gas receptacles transported for recycling or disposal go in stowage category C and must be clear of living quarters. ERG Guide 126 cautions that aerosols (UN1950) may contain a flammable propellant even when the Division is 2.2.

ERG 2024 Guide 126: Gases - Compressed or Liquefied (Including Refrigerant Gases)

The ERG 2024 numerical index lists UN1950 against Guide 126. The guide appears on pages 181 to 182 of the 2024 guidebook. The guidebook is meant for first responders during the initial phase of an incident, and it says to call 911 and then the emergency response telephone number on the shipping paper.

• Fire or explosion: "Some may burn but none ignite readily", containers may explode when heated, and ruptured cylinders may rocket. The guide cautions that aerosols (UN1950) may contain a flammable propellant.
• Health: vapors may cause dizziness or asphyxiation without warning in closed or confined areas, and contact with liquefied gas may cause burns, severe injury or frostbite.
• Evacuation: isolate a spill or leak area for at least 100 meters (330 feet) in all directions; for a large spill consider initial downwind evacuation of at least 500 meters (1/3 mile); for a tank, rail tank car or highway tank in a fire, isolate for 800 meters (1/2 mile).
• Fire response: use an extinguishing agent suitable for the surrounding fire; small fire, dry chemical or CO2; large fire, water spray, fog or regular foam.

The guide is a starting point until the material is identified. Read the full guide in the current ERG, and use the shipping paper emergency number for product-specific advice.

Placards, quantity and vessel stowage

The rows are in Divisions 2.2 and 2.1, all Table 2 categories in 172.504(e): Division 2.2 takes NON-FLAMMABLE GAS, Division 2.1 takes FLAMMABLE GAS. Subsidiary hazard placards (172.505) are not modeled. On a highway vehicle with less than 454 kg (1,001 pounds) aggregate gross weight of Table 2 materials in non-bulk packages, no placard is required, but bulk packagings and materials subject to 172.505 are not eligible for that exception (172.504(c)).

Vessel stowage is the category in column 10A (A), which the table sets for this entry, plus the column 10B codes. Hazmat shipped as a limited quantity is allocated stowage category A and is not subject to the column 10B stowage codes (176.63(a)).

• 25: Protected from sources of heat.
• 87: Stow "separated from" Class 1 (explosives) except Division 1.4.
• 126: Segregation same as for Class 9, miscellaneous hazardous materials.
• 157: For aerosols and gas receptacles transported for recycling or disposal, stowage category C applies and stowage must be clear of living quarters.

Worked example

A cleaning-products distributor ships 24 cans of 400 mL flammable aerosol, a Division 2.1 entry, by highway. Each can is under the 1 L capacity limit in 173.306(a)(3). A case with a net contents weight of 12 kg is within the 75 kg passenger aircraft limit and the 150 kg cargo aircraft limit. A pickup with 600 pounds of Division 2.1 aerosols not in bulk is under the 1,001 pound threshold in 172.504(c), so no FLAMMABLE GAS placard is required, and conforming limited quantity packages are not subject to the placarding subpart at all.

Limits

This page reads the 172.101 table, the 172.102 special provisions, 172.504 and the section titles named above, plus ERG 2024. It does not classify your material, choose a proper shipping name, or build shipping papers, marks, labels or training requirements. The checker compares your net quantity to the printed column 9A and 9B limits and applies the 1,001 pound rule to the class on the row; it does not model subsidiary hazard placards (172.505), mixed loads, state rules or carrier restrictions. Special provisions are shown in summary; read the full text in 172.102 before relying on one. Hazmat shipping needs trained hazmat employees (49 CFR part 172, subpart H).

Sources

Sources opened and read November 2, 2026.

• eCFR: 49 CFR 172.101, Hazardous Materials Table (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 172.102, special provisions (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 172.504, general placarding requirements (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 173.115, Class 2 definitions (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 173.306, Limited quantities of compressed gases (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 176.84, other requirements for stowage, cargo handling and segregation (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 176.63, stowage locations (current through October 29, 2026) (read November 2, 2026)
• PHMSA: Emergency Response Guidebook (ERG) landing page (read November 2, 2026)
• PHMSA: ERG 2024 PDF, numerical index and guide pages (the phmsa.dot.gov host refused automated requests; the Internet Archive copy of this file was read) (read November 2, 2026)