Analyze an SDS

DOT Division 2.2: Non-Flammable, Non-Poisonous Gas

Division 2.2 is the DOT division for non-flammable, non-poisonous gases. These gases are shipped under pressure or as refrigerated liquids and include asphyxiants such as nitrogen and argon and oxidizing gases such as oxygen. They are hazardous mainly because of pressure, cold or oxygen displacement.

How it is defined

  • The division includes simple asphyxiants, gases that dilute or replace oxygen in the air.
  • It also includes oxidizing gases, which can cause or help combustion more than air; these carry an additional oxidizer label.
  • Refrigerated liquefied gases (cryogenic liquids) such as liquid nitrogen are classified here when not flammable or toxic.

Summary of 49 CFR Parts 171 to 180. The regulations and the Hazardous Materials Table (49 CFR 172.101) control any shipment.

Label and placard

Colors
Green background, black or white cylinder
Symbol
Gas cylinder

A green diamond label and placard showing a gas cylinder and the number 2.

Packing groups

None. How packing groups work.

Common examples

  • Nitrogen, argon, helium
  • Carbon dioxide (including as a refrigerated liquid)
  • Oxygen (with oxidizer subsidiary label)
  • Compressed air
  • Refrigerant gases that are non-flammable

How it relates to GHS

Corresponds to GHS gases under pressure (gas cylinder pictogram GHS04) and, for oxygen and similar gases, oxidizing gases (flame over circle, GHS03).

DOT classes and GHS classes are assigned under different rules, so a product can have different severity labels in each. See also all GHS hazard classes.

Safe handling reminders

  • Confirm adequate ventilation or oxygen monitoring where asphyxiant gases are used or stored.
  • Secure cylinders upright and cap them.
  • Cryogenic liquids need face protection, insulated gloves and vented containers.

Where to find it on an SDS

Section 14 shows Class 2, Division 2.2, a UN number such as UN1066 for nitrogen, and any subsidiary hazard. Look in Section 14: Transport information. Hazard classification for the workplace is in Section 2. You can also see how a UN number points to a response guide on the UN and NA numbers page.

Frequently asked questions

Is a Division 2.2 gas safe?

Not automatically. Division 2.2 gases are not flammable or toxic, but cylinders can rupture, cryogenic liquids can cause cold burns, and asphyxiants can displace oxygen in enclosed spaces.

General reference only. It does not replace the supplier's SDS or the current federal regulations.