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

Chloropicrin and methyl bromide mixtures

HMT 15 June 2026

UN / ID: UN 1581
Hazard class: 2.3
Packing group: —
ERG guide: ERG 123
Special provisions: SP 2, SP B9, SP B14, SP N86, SP T50
Source: 49 CFR §172 (15 June 2026)

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Chloropicrin and methyl bromide mixtures

Chloropicrin, also known as PS (from Port Sunlight) and nitrochloroform, is a chemical compound currently used as a broad-spectrum antimicrobial, fungicide, herbicide, insecticide, and nematicide. It was used as a poison gas in World War I. Its chemical structural formula is Cl3C−NO2 Wikipedia

Emergency Response Guide No. 123

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard class

2.3
Poisonous gas

(4) Identification number

UN 1581

(5) Packing Group

—

(6) Labels

(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.

2	This material is poisonous by inhalation (see § 171.8 of this subchapter) in Hazard Zone B (see § 173.116(a) or § 173.133(a) of this subchapter), and must be described as an inhalation hazard under the provisions of this subchapter. Browse special provision 2
B9	Bottom outlets are not authorized. Browse special provision B9
B14	Each bulk packaging, except a tank car or a multi-unit-tank car tank, must be insulated with an insulating material so that the overall thermal conductance at 15.5 °C (60 °F) is no more than 1.5333 kilojoules per hour per square meter per degree Celsius (0.075 Btu per hour per square foot per degree Fahrenheit) temperature differential. Insulating materials must not promote corrosion to steel when wet. Browse special provision B14
N86	UN pressure receptacles made of aluminum alloy are not authorized. Browse special provision N86
T50	When portable tank instruction T50 is indicated in Column (7) of the § 172.101 Hazardous Materials Table, the applicable liquefied compressed gas and chemical under pressure descriptions are authorized to be transported in portable tanks in accordance with the requirements of § 173.313 of this subchapter. Browse special provision T50

(8) Packing Authorizations (§173.***)

(8A) Exceptions	None
(8B) Non-bulk	193	see 49 CFR §173.193
(8C) Bulk	314, 315	see 49 CFR §173.314, 315

(9) Quantity Limits

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

(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

25	see 49 CFR §176.84
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 B). See special provision 2 and PHMSA Interpretation #09-0252.

Hazard class	8	7	6.1	5.2	5.1	4.3	4.2	4.1	3	2.3B	2.3A	2.2	2.1	1.6	1.5	1.4	1.3	1.1/1.2
1.1/1.2
1.3
1.4
1.5
1.6
2.1
2.2
2.3A
2.3B
3
4.1
4.2
4.3
5.1
5.2
6.1
7
8

	Must not be loaded, transported, or stored together in the same vehicle or facility.
	May be loaded, transported, or stored together.
	May be loaded, transported, or stored together only with restrictions.

Similar substances

UN / ID	Proper shipping name	Hazard class
	Chloropicrin mixture, flammable (pressure not exceeding 14.7 psia at 115 degrees F flash point below 100 degrees F) see Toxic liquids, flammable, etc
UN 1582	Chloropicrin and methyl chloride mixtures	2.3
UN 1583	Chloropicrin mixtures, n.o.s	6.1
	Methyl bromide and chloropicrin mixtures with not more than 2 percent chloropicrin, see Methyl bromide
UN 1580	Chloropicrin	6.1