HazMat Tool — substance information Reference only — not a shipping paper, placard mandate, or CVI record.

Carbon monoxide, compressed

HMT 15 June 2026

UN / ID: UN 1016
Hazard class: 2.3
Packing group: —
ERG guide: ERG 119
Special provisions: SP 4
Source: 49 CFR §172 (15 June 2026)

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Carbon monoxide, compressed

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

—

Boiling Point

—

Emergency Response Guide No. 119

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard class

2.3
Poisonous gas

(4) Identification number

UN 1016

(5) Packing Group

—

(6) Labels

Cargo Aircraft Only (Cargo Aircraft Only)

(7) Special Provisions (§172.102)

×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	This material is poisonous by inhalation (see § 171.8 of this subchapter) in Hazard Zone D (see § 173.116(a) of this subchapter), and must be described as an inhalation hazard under the provisions of this subchapter. Browse special provision 4

(8) Packing Authorizations (§173.***)

(8A) Exceptions	None
(8B) Non-bulk	302	see 49 CFR §173.302
(8C) Bulk	314, 315	see 49 CFR §173.314, 315

(9) Quantity Limits

(9A) Passenger aircraft/rail	Forbidden
(9B) Cargo aircraft only	25 kg

(10) Vessel stowage

(10A) Location

Stowage category “D” means the material must be stowed “on deck only” on a cargo vessel or on a passenger vessel carrying a number of passengers limited to not more than the larger of 25 passengers or one passenger per each 3 m of overall vessel length, but the material is prohibited on a passenger vessel in which the limiting number of passengers is exceeded.

Source: 49 CFR §172.101(k)

(10B) Other

40	see 49 CFR §176.84

Source: 49 CFR §176.84

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.

Note: In this segregation and separation chart are HazMat of hazard class 2.3 considered depending on their poisonousness by inhalation (Hazard zone A/B). See PHMSA Interpretation #09-0252.

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

Similar substances

UN / ID	Proper shipping name	Hazard class
UN 0222	Ammonium nitrate, with more than 0.2 percent combustible substances, including any organic substance calculated as carbon, to the exclusion of any other added substance	1.1D
UN 1942	Ammonium nitrate, with not more than 0.2% combustible substances, including any organic substance calculated as carbon, to the exclusion of any other added substance	5.1
UN 1041	Ethylene oxide and carbon dioxide mixtures with more than 9 percent but not more than 87 percent ethylene oxide	2.1
UN 3150	Devices, small, hydrocarbon gas powered or Hydrocarbon gas refills for small devices with release device	2.1
UN 1010	Butadienes, stabilized or Butadienes and Hydrocarbon mixture, stabilized containing more than 40% butadienes	2.1
UN 1952	Ethylene oxide and carbon dioxide mixtures with not more than 9 percent ethylene oxide	2.2
UN 3300	Ethylene oxide and carbon dioxide mixture with more than 87 percent ethylene oxide	2.3
	Di-n-butyl peroxydicarbonate, with more than 52 percent in solution	Forbidden
	Dibenzyl peroxydicarbonate, with more than 87 percent with water	Forbidden
	Diethyl peroxydicarbonate, with more than 27 percent in solution	Forbidden
UN 1058	Liquefied gases, non-flammable charged with nitrogen, carbon dioxide or air	2.2
	n-Butyl peroxydicarbonate, with more than 52 percent in solution	Forbidden
UN 1379	Paper, unsaturated oil treated incompletely dried (including carbon paper)	4.2
UN 1845	Carbon dioxide, solid or Dry ice	9
UN 1361	Carbon, animal or vegetable origin	4.2