HazMat Tool — substance information

Carbon monoxide, refrigerated liquid (cryogenic liquid)

HMT May 2026
UN / ID
NA 9202
Hazard class
2.3
Packing group
ERG guide
Special provisions
SP 4, SP T75, SP TP5
Source
49 CFR §172 (2026/05)

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Carbon monoxide, refrigerated liquid (cryogenic liquid)


Carbon monoxide (chemical formula CO) is a poisonous, flammable gas that is colorless, odorless, tasteless, and slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simplest carbon oxide. In coordination complexes, the carbon monoxide ligand is called carbonyl. Wikipedia

Substance Data

Source: PubChem (HSDB, 04.12.2019)

CAS-Number

630-08-0

Flash Point

n/a

Boiling Point

n/a

Hazardous Materials Table

Source: 49 CFR §172 (2026/05)

(3) Hazard Class

2.3
Poisonous gas

(4) Identification number Help

NA 9202

(5) Packing Group Help

n/a

(6) Labels Help

Poisonous gas (2.3) Flammable gases (2.1)

(1) Symbols Help


This entry is signed with "D". The letter "D" identifies proper shipping names which are appropriate for describing materials for domestic transportation but may be inappropriate for international transportation under the provisions of international regulations (e.g., IMO, ICAO). An alternate proper shipping name may be selected when either domestic or international transportation is involved.

(7) Special Provisions (§172.102) Help

×Note:
Special provisions may be very complex. The extracts are taken from 49 CFR §172.102. Please be careful with the information, as necessary, additional conditions may be applied that are not written here. Please check the original source and report bugs.
4
T75
TP5

(8) Packing Authorizations (§173.***) Help

(8A) ExceptionsNone
(8B) Non-bulk316see 49 CFR §173.316
(8C) Bulk318see 49 CFR §173.318

(9) Quantity Limits Help

(9A) Passenger aircraft/railForbidden
(9B) Cargo aircraft onlyForbidden

(10) Vessel stowage Help

(10A) Location
(10B) Other n/a

Segregation chart for load, transport, and storage

This chart shows whether loading, transport, or storage with other hazard classes is permitted, prohibited, or restricted. Based on 49 CFR §177.848.

Scope & sources (important)Click to show CFR references

This check evaluates segregation per 49 CFR §177.848. Additional loading/unloading and handling requirements may still apply; see 49 CFR §177 Subpart B (Loading and Unloading):

  • §177.834 - General requirements
  • §177.835 - Class 1 materials
  • §177.837 - Class 3 materials
  • §177.838 - Class 4 (flammable solid) materials, Class 5 (oxidizing) materials, and Division 4.2 (pyroforic liquid) materials
  • §177.839 - Class 8 (corrosive) materials
  • §177.840 - Class 2 (gases) materials
  • §177.841 - Division 6.1 and Division 2.3 materials
  • §177.842 - Class 7 (radioactive) material
  • §177.843 - Contamination of vehicles