GHS hazard class · Physical hazards

Self-heating substances and mixtures

Self-heating substances and mixtures are solids or liquids, other than pyrophoric ones, that can heat up by reaction with air without any outside energy supply. They may ignite only in large amounts and after long periods (hours or days).

Flame

What it means

Heat can build up inside a pile, bag or drum until the material catches fire, especially in large quantities.

What to do

Keep in small quantities and in cool, well-ventilated storage, avoid stacking in large piles, keep away from heat, and follow the maximum storage quantities and temperatures given by the supplier.

This is general guidance for the class. Your product's safety data sheet takes precedence.

Categories and hazard statements

Code	Category	Statement	Pictogram	Signal word
H251	Category 1	Self-heating; may catch fire	GHS02	Danger
H252	Category 2	Self-heating in large quantities; may catch fire	GHS02	Warning

Chemicals with self-heating substances and mixtures hazard codes

Chemicals in our database whose primary classification includes any current Self-heating substances and mixtures code (H251, H252).

No chemicals in our database carry these codes yet.

Self-heating substances and mixtures: frequently asked questions

What is the GHS hazard class "Self-heating substances and mixtures"?

Which hazard statements belong to Self-heating substances and mixtures?

The current hazard statements for this class are H251, H252.

Which pictograms and signal words are used for Self-heating substances and mixtures?

Pictograms: GHS02 (Flame). Signal words: Danger or Warning, depending on the category.

What should I do when working with a self-heating substances and mixtures hazard?

Keep in small quantities and in cool, well-ventilated storage, avoid stacking in large piles, keep away from heat, and follow the maximum storage quantities and temperatures given by the supplier.

https://pubchem.ncbi.nlm.nih.gov/ghs/ghscode_10.txt (UN GHS Revision 10, retrieved 2026-10-12)