HazMat Tool — substance information

Methyl isothiocyanate

HMT May 2026
UN / ID
UN 2477
Hazard class
6.1
Packing group
I
ERG guide
ERG 131
Special provisions
SP 2, SP B9, SP B14, SP B32, SP T20, SP TP2, SP TP13, SP TP38, more…
Source
49 CFR §172 (2026/05)

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Methyl isothiocyanate


Methyl isothiocyanate is the organosulfur compound with the formula CH3−N=C=S. This low melting colorless solid is a powerful lachrymator. As a precursor to a variety of valuable bioactive compounds, it is the most important organic isothiocyanate in industry. Wikipedia

Substance Data

Source: PubChem (HSDB, 24.11.2019)

CAS-Number

556-61-6

Flash Point

n/a

Boiling Point

n/a

Emergency Response Guide No. 131

Hazardous Materials Table

Source: 49 CFR §172 (2026/05)

(3) Hazard Class

6.1
Poisonous Material

(4) Identification number Help

UN 2477

(5) Packing Group Help

I

(6) Labels Help

Poisonous liquids PG I Zone A (6.1) Flammable liquids (3)

(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.
2
B9
B14
B32
T20
TP2
TP13
TP38
TP45

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

(8A) ExceptionsNone
(8B) Non-bulk227see 49 CFR §173.227
(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.

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 / IDProper shipping nameHazard class
UN 1545Allyl isothiocyanate, stabilized6.1