Oxygen signs, their application and compliance

See all of our Oxygen Signs

What is Oxygen?

Oxygen is an odorless, colorless gas or colorless to pale blue cryogenic liquid. Besides supporting life via our respiratory system, oxygen is used in various industries from steel manufacturing, aerospace technology and the treatment of sewage to name a few.

Oxygen is not flammable, but as an oxidizer it will intensify combustion or fires. With this clear hazard warning, oxygen must be kept away from combustible materials. Liquid oxygen also poses a health hazard for individuals, exposure may cause frostbite to the eyes and skin. It is key to follow safety practices and wear appropriate personal protection equipment to prevent serious accidents or injury.

Fire Protection Guide to Hazardous Materials - Edition 14th

*Refrigerated liquid oxygen can have a high health hazard degree of “3” because compressed liquified gases with boiling points at or below -55°C (-66.5°F) can cause frostbite and irreversible tissue damage. Refrigerated liquid oxygen has a boiling point of -183°C (-297°F).

Other Hazard Ratings

The other ratings that appear on the Oxygen signs page, besides those listed in NFPA's Fire Protection Guide to Hazardous Materials - Edition 14th, were found in other documentation.

NFPA 49 Chapter 5 Hazardous Chemical Data Sheet

The Hazardous Chemical Data Compilation, previously known as NFPA 49, provides guidance on the hazards of chemicals to emergency personnel, safety professionals, inspection and enforcement officials on storage and fire fighting techniques that can be used in an emergency or in disaster planning.

Name: OXYGEN, refrigerated liquid

Formula: O₂

NFPA 30/OSHA Classification: n/a

DOT Class: Class 2.2, Non-flammable compressed gas

Shipping Label: NONFLAMMABLE GAS and OXIDIZER

ID No: UN 1073 refrigerated liquid

CAS No: 7782-44-7

Statement of Hazards: Strong oxidizer. Contact with liquid will cause frostbite. May initiate fire/explosion in combustible materials.

Emergency Response Personal Protective Equipment: Wear special protective clothing and positive pressure self-contained breathing apparatus.

Spill or Leak Procedures: A leak of liquid oxygen onto combustible material represents a severe explosion potential. Eliminate all ignition sources. Stop or control the leak. If this can be done without undue risk. Use water spray to disperse vapors and protect personnel.

Fire Fighting Procedures: Extinguish fire using agent suitable for surrounding fire. Use water spray to keep fire-exposed containers cool.

Health Hazards: Contact with liquid will cause frostbite.

Fire and Explosion Hazards: Not combustible, but readily supports combustion/explosion of organic matter and other oxidizable materials. Clothing that becomes saturated with oxygen becomes a severe fire hazard.

Instability and Reactivity Hazards: Readily oxidises many materials, some violently.

Storage Recommendations: Store in an open area. Separate from combustible materials.

Physical Properties: Colorless to pale blue, cryogenic liquid or colorless gas. Odorless.

Melting Point: -361°F (-218°C)

Boiling Point: -297°F (-183°C)

Specific Gravity: 1.4

Solubility in Water: not soluble

Vapor Density: 1.10

Transport Information

Hazmat Placards are required for the transportation of oxygen. Domestically in the US, the Department of Transportation allows the display of the word “OXYGEN” with class number 2 on the label, instead of the UN ID numbers. Internationally, the transport of oxygen may require the use of UN1072 identification for compressed gas or UN1073 for refrigerated liquid along with an Oxidizer 5.1 placard.

49 CFR

§172.405 Authorized label modifications.

(b) For a package containing Oxygen, compressed, or Oxygen, refrigerated liquid, the OXIDIZER label specified in §172.426 of this subpart, modified to display the word “OXYGEN” instead of “OXIDIZER”, and the class number “2” instead of “5.1”, may be used in place of the NON-FLAMMABLE GAS and OXIDIZER labels. Notwithstanding the provisions of paragraph (a) of this section, the word “OXYGEN” must appear on the label.

§172.504 General placarding requirements.

(3) A NON-FLAMMABLE GAS placard is not required on a transport vehicle which contains non-flammable gas if the transport vehicle also contains flammable gas or oxygen and it is placarded with FLAMMABLE GAS or OXYGEN placards, as required.

(4) OXIDIZER placards are not required for Division 5.1 materials on freight containers, unit load devices, transport vehicles or rail cars which also contain Division 1.1 or 1.2 materials and which are placarded with EXPLOSIVES 1.1 or 1.2 placards, as required.

(5) For transportation by transport vehicle or rail car only, an OXIDIZER placard is not required for Division 5.1 materials on a transport vehicle, rail car or freight container which also contains Division 1.5 explosives and is placarded with EXPLOSIVES 1.5 placards, as required.

(6) The EXPLOSIVE 1.4 placard is not required for those Division 1.4 Compatibility Group S (1.4S) materials that are not required to be labeled 1.4S.

(7) For domestic transportation of oxygen, compressed or oxygen, refrigerated liquid, the OXYGEN placard in §172.530 of this subpart may be used in place of a NON-FLAMMABLE GAS placard.

§172.519 General specifications for placards.

(3) For other than Class 7 or the DANGEROUS placard, text indicating a hazard (for example, “FLAMMABLE”) is not required. Text may be omitted from the OXYGEN placard only if the specific identification number is displayed on the placard.

§172.530 OXYGEN placard.

(a) Except for size and color, the OXYGEN placard must be as follows:

(b) In addition to complying with §172.519 of this subpart, the background color on the OXYGEN placard must be yellow. The symbol, text, class number and inner border must be black.