HazMat Tool — substance information

Cesium or Caesium

HMT May 2026
UN / ID
UN 1407
Hazard class
4.3
Packing group
I
ERG guide
ERG 138
Special provisions
SP A7, SP A19, SP IB4, SP IP1, SP N34, SP N40, SP W31
Source
49 CFR §172 (2026/05)

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Cesium or Caesium

Substance Data

Source: PubChem (HSDB, 30.11.2019)

CAS-Number

7440-46-2

Flash Point

n/a

Boiling Point

n/a

Emergency Response Guide No. 138

Hazardous Materials Table

Source: 49 CFR §172 (2026/05)

(3) Hazard Class

4.3
Dangerous when wet materials

(4) Identification number Help

UN 1407

(5) Packing Group Help

I

(6) Labels Help

Dangerous when wet materials (4.3) Cargo Aircraft Only (Cargo Aircraft Only)

(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.
A7
A19
IB4
IP1
N34
N40
W31

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

(8A) ExceptionsNone
(8B) Non-bulk211see 49 CFR §173.211
(8C) Bulk242see 49 CFR §173.242

(9) Quantity Limits Help

(9A) Passenger aircraft/railForbidden
(9B) Cargo aircraft only15 kg

(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.

Similar substances

UN / IDProper shipping nameHazard class
UN 1451Cesium nitrate or Caesium nitrate5.1
UN 2681Caesium hydroxide solution8