Encyclopedia
0th class
Zone 0 — areas in which an explosive gas or vapor-air mixture is present continuously or for at least one hour1.
Federal Law No. 123-FZ of July 22, 2008 "Technical Regulation on Fire Safety Requirements", as amended on July 1, 2019, Article 19, Subparagraph 1 // RSFSR Gazette. 2008. No. 30. Item 3579. ↩