HazMat Tool — substance information

Trichlorosilane

HMT May 2026
UN / ID
UN 1295
Hazard class
4.3
Packing group
I
ERG guide
ERG 139
Special provisions
SP N34, SP T14, SP TP2, SP TP7, SP TP13, SP W31
Source
49 CFR §172 (2026/05)

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Trichlorosilane


Trichlorosilane (TCS) is an inorganic compound with the formula HCl3Si. It is a colourless, volatile liquid. Purified trichlorosilane is the principal precursor to ultrapure silicon in the semiconductor industry. In water, it rapidly decomposes to produce a siloxane polymer while giving off hydrochloric acid. Wikipedia

Substance Data

Source: PubChem (HSDB, 19.11.2019)

CAS-Number

10025-78-2

Flash Point

n/a

Boiling Point

n/a

Emergency Response Guide No. 139

Hazardous Materials Table

Source: 49 CFR §172 (2026/05)

(3) Hazard Class

4.3
Dangerous when wet materials

(4) Identification number Help

UN 1295

(5) Packing Group Help

I

(6) Labels Help

Dangerous when wet materials (4.3) Flammable liquids (3) Corrosive liquids (8)

(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.
N34
T14
TP2
TP7
TP13
W31

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

(8A) ExceptionsNone
(8B) Non-bulk201see 49 CFR §173.201
(8C) Bulk244see 49 CFR §173.244

(9) Quantity Limits Help

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

(10) Vessel stowage Help

(10A) Location
(10B) Other

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.

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