This document specifies the general requirements and tests for decomposition blockers downstream of pressure regulators in acetylene manifold systems (see ISO 14114). Decomposition blockers can be used in the low-pressure section (downstream of acetylene manifold system outlet) up to 0,15 MPa (1,5 bar) e.g. in pipelines, outlet points or for the protection of low-pressure sections in big pipe systems. Decomposition blockers can only be used in sections with pure acetylene. The possible backflow of oxygen or air into the section where the decomposition blocker is installed needs to be prevented by a non-return valve downstream of the decomposition blocker.