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Methylchlorosilane

HMT 15 June 2026

UN / ID: UN 2534
Hazard class: 2.3
Packing group: — (multiple — see tabs)
ERG guide: ERG 119
Special provisions: SP 2, SP B9, SP B14, SP N34
Source: 49 CFR §172 (15 June 2026)

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Methylchlorosilane

Emergency Response Guide No. 119

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

Packing group
Packing group

(3) Hazard class

2.3
Poisonous gas

(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
N34	Aluminum construction materials are not authorized for any part of a packaging which is normally in contact with the hazardous material. Browse special provision N34

(8) Packing Authorizations (§173.***)

(8A) Exceptions	None
(8B) Non-bulk	226	see 49 CFR §173.226
(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

17	see 49 CFR §176.84
40	see 49 CFR §176.84

Source: 49 CFR §176.84

(3) Hazard class

3
Flammable liquids

(4) Identification number

UN 1298

(5) Packing Group

Comparison View of PG

(6) Labels

Cargo Aircraft Only (Cargo Aircraft Only)

(7) Special Provisions (§172.102)

For combination packagings, if glass inner packagings (including ampoules) are used, they must be packed with absorbent material in tightly closed rigid and leakproof receptacles before packing in outer packagings.

Browse special provision A3

Steel packagings must be corrosion-resistant or have protection against corrosion.

Browse special provision A7

B77

Other packaging are authorized when approved by the Associate Administrator.

Browse special provision B77

N34

Aluminum construction materials are not authorized for any part of a packaging which is normally in contact with the hazardous material.

Browse special provision N34

T10

Minimum test pressure (bar)	4
Minimum shell thickness	6 mm
Pressure-relief requirements	§ 178.275(g)(3)
Bottom opening requirements	Prohibited

Browse special provision T10

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

TP13

Self-contained breathing apparatus must be provided when this hazardous material is transported by sea.

Browse special provision TP13

(8) Packing Authorizations (§173.***)

(8A) Exceptions	None
(8B) Non-bulk	206	see 49 CFR §173.206
(8C) Bulk	243	see 49 CFR §173.243

(9) Quantity Limits

(9A) Passenger aircraft/rail	Forbidden
(9B) Cargo aircraft only	5 L

(10) Vessel stowage

(10A) Location

Stowage category “E” means the material may be stowed “on deck” or “under deck” 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 is prohibited from carriage 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
53	see 49 CFR §176.84
58	see 49 CFR §176.84

Source: 49 CFR §176.84

Packing group comparison

Multiple packing groups apply to this entry. See assignment criteria in 49 CFR §173 Subpart D. Details are in the tabs above; differences are highlighted.

	PG —	PG II
1
2	Methylchlorosilane	Trimethylchlorosilane
3	2.3	3
4	UN 2534	UN 1298
5	—	II
6	2.3, 2.1, 8	3, 8
7	2, B9, B14, N34	A3, A7, B77, N34, T10, TP2, TP7, TP13
8A	None	None
8B	226	206
8C	314, 315	243
9A	Forbidden	Forbidden
9B	Forbidden	5 L
10A	D	E
10B	17, 40	40, 53, 58

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.

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