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Pyrophoric liquids, organic, n.o.s

HMT 15 June 2026

UN / ID: UN 2845
Hazard class: 4.2
Packing group: I
ERG guide: ERG 135
Special provisions: SP B11, SP T22, SP TP2, SP TP7, SP W31
Source: 49 CFR §172 (15 June 2026)

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Pyrophoric liquids, organic, n.o.s

A substance is pyrophoric (from Ancient Greek: πυροφόρος, pyrophoros, 'fire-bearing') if it ignites spontaneously in air at or below 54 °C (129 °F) (for gases) or within five minutes after coming into contact with air (for liquids and solids). Examples are organolithium compounds and triethylborane, as well as actinides. Pyrophoric materials are often water-reactive as well and will ignite when they contact water or humid air. They can be handled safely in atmospheres of argon or (with a few exceptions) nitrogen Wikipedia

Emergency Response Guide No. 135

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard class

4.2
Spontaneously combustible materials

(4) Identification number

UN 2845

(5) Packing Group

(6) Labels

Spontaneously combustible materials (4.2)

(1) Symbols

This entry is signed with "G". The letter "G" identifies proper shipping names for which one or more technical names of the hazardous material must be entered in parentheses, in association with the basic description. (See §172.203(k)).

(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.

B11

Tank car tanks must have a test pressure of at least 2,068.5 kPa (300 psig). Cargo and portable tanks must have a design pressure of at least 1,207 kPa (175 psig).

Browse special provision B11

T22

Minimum test pressure (bar)	10
Minimum shell thickness	10 mm
Pressure-relief requirements	§ 178.275(g)(3)
Bottom opening requirements	Prohibited

Browse special provision T22

TP2

a. The maximum degree of filling must not exceed the degree of filling determined by the following:
TP2a

Where:
t_r is the maximum mean bulk temperature during transport,
t_f is the temperature in degrees celsius of the liquid during filling, and
α is the mean coefficient of cubical expansion of the liquid between the mean temperature of the liquid during filling (t_f) and the maximum mean bulk temperature during transportation (t_r) both in degrees celsius.
b. For liquids transported under ambient conditions α may be calculated using the formula:
TP2b

Where:
d₁₅ and d₅₀ are the densities (in units of mass per unit volume) of the liquid at 15 °C (59 °F) and 50 °C (122 °F), respectively.

Browse special provision TP2

TP7

The vapor space must be purged of air by nitrogen or other means.

Browse special provision TP7

W31

Non-bulk packagings must be hermetically sealed.

Browse special provision W31

(8) Packing Authorizations (§173.***)

(8A) Exceptions	None
(8B) Non-bulk	187	see 49 CFR §173.187
(8C) Bulk	244	see 49 CFR §173.244

(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

13	see 49 CFR §176.84
78	see 49 CFR §176.84
148	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.

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
UN 2441	Titanium trichloride, pyrophoric or Titanium trichloride mixtures, pyrophoric	4.2
NA 2845	Ethyl phosphonous dichloride, anhydrous pyrophoric liquid	6.1
UN 3394	Organometallic substance, liquid, pyrophoric, water-reactive	4.2
UN 3393	Organometallic substance, solid, pyrophoric, water-reactive	4.2
UN 1855	Calcium, pyrophoric or Calcium alloys, pyrophoric	4.2
NA 2845	Methyl phosphonous dichloride, pyrophoric liquid	6.1
UN 1383	Pyrophoric metals, n.o.s., or Pyrophoric alloys, n.o.s	4.2
UN 3392	Organometallic substance, liquid, pyrophoric	4.2
UN 3391	Organometallic substance, solid, pyrophoric	4.2
UN 1854	Barium alloys, pyrophoric	4.2
UN 3194	Pyrophoric liquid, inorganic, n.o.s	4.2
UN 3200	Pyrophoric solid, inorganic, n.o.s	4.2
UN 0380	Articles, pyrophoric	1.2L
UN 2846	Pyrophoric solids, organic, n.o.s	4.2