HazMat Tool — substance information
Calcium, pyrophoric or Calcium alloys, pyrophoric
HMT 15 June 2026- UN / ID
- UN 1855
- Hazard class
- 4.2
- Packing group
- I
- ERG guide
- ERG 135
- Special provisions
- SP W31
- Source
- 49 CFR §172 (15 June 2026)
Calcium, pyrophoric or Calcium alloys, pyrophoric
Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium Wikipedia
| Emergency Response Guide No. 135 |
Hazardous Materials Table
Source: 49 CFR §172 (15 June 2026)(3) Hazard Class4.2Spontaneously combustible materials |
(4) Identification number |
(5) Packing Group |
|||||||
(6) Labels |
|||||||||
(7) Special Provisions (§172.102)
|
|||||||||
| W31 |
|---|
(8) Packing Authorizations (§173.***) 
| (8A) Exceptions | None | |
|---|---|---|
| (8B) Non-bulk | 187 | see 49 CFR §173.187 |
| (8C) Bulk | None |
(9) Quantity Limits 
| (9A) Passenger aircraft/rail | Forbidden |
|---|---|
| (9B) Cargo aircraft only | Forbidden |
(10) Vessel stowage 
| (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.
| 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. |