d1e840-87-1__para
As already indicated, a substance is assigned H260 or H261 if it is capable of releasing a highly flammable gas at a rate in excess of 1 litre of gas per kilogram of substance per hour when water is added.
Source: EUR-Lex (Cellar) · retrieved 2026-09-25 · Text as adopted (Official Journal); later amendments are not incorporated in this text.