In many industries dealing with flammable, combustible and explosive materials such as petroleum, petroleum products, chemistry, LPG, natural gas, coal mines, grain silos, sugar factories, timber and furniture factories, bread ovens and factories, such as normal operation or breakdown and maintenance. In such cases (for reasons such as gas, dust, or flammable substance vapor), an explosive atmosphere occurs. Sparks and arcs from electrical appliances endanger these environments and cause explosions.