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Flammable Gas

DOT Flammable Gas Division 2 Placard

Be sure you're in compliance with DOT placards and labels from Safety Emporium.


Flammable gases are defined by the U.S. Department of Transportation under 49 CFR 173.115 (Subpart D) as:

"...any material which is a gas at 20 oC (68 oF) or less and 101.3 kPa (14.7 psi) of pressure (a material which has a boiling point of 20 oC (68 oF) or less at 101.3 kPa (14.7 psi)) which -

  1. Is ignitable at 101.3 kPa (14.7 psi) when in a mixture of 13 percent or less by volume with air; or
  2. Has a flammable range at 101.3 kPa (14.7 psi) with air of at least 12 percent regardless of the lower limit.

Except for aerosols, the limits specified in paragraphs (a)(1) and (a)(2) of this section shall be determined at 101.3 kPa (14.7 psi) of pressure and a temperature of 20 oC (68 oF) in accordance with ASTM E681-09, Standard Test Method for Concentration Limits of Flammability of Chemicals or other equivalent method approved by the Associate Administrator for Hazardous Materials Safety.

Note: 101.3 kPa (14.7 psi) = normal atmospheric pressure, also denoted 1 atm.

Additional Info

DOT classifies flammable gases as Division 2.1 and requires warning labels and placards for shipments of such materials. See DOT Chart 15: Hazardous Materials Markings, Labeling and Placarding Guide for more information on placarding and shipping label requirements.

SDS Relevance

If applicable and known, flammable and explosive limits will appear in Section 9 (physical and chemical properties) of the Safety Data Sheet.

Always know the explosive/flammable limits for any flammable gas. For those who routinely work around flammable materials, special detectors are available that can indicate when conditions are within the flammable limits.

You must be properly trained in working with any kind of gas as these can present not only fire, poison, or explosion hazards, but the risk of asphyxiation. OSHA has special standards that apply to propane-powered lifts and forklifts as well.

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Safety Emporium has gas cylinder signs, racks, carts, clamps, lockouts and more to ensure your workers' safety.

Further Reading

See also: combustible, flammable aerosol, flammable, flash point.

Additional definitions from Google and OneLook.

Entry last updated: Thursday, October 6, 2022. This page is copyright 2000-2024 by ILPI. Unauthorized duplication or posting on other web sites is expressly prohibited. Send suggestions, comments, and new entry desires (include the URL if applicable) to us by email.

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