Mine safety in coal mines, which in turn can initiate more extensive coal dust explosions. For this reason, rock dusts such as limestone dust are spread throughout coal mines to diminish the chances of coal dust explosions as well as to limit the extent of potential explosions, in a process known as rock dusting. Coal dust explosions can also begin independently of methane gas explosions. Frictional heat and sparks generated by mining equipment can ignite both methane gas and coal dust. For this reason, water is often used to cool rock-cutting sites. Miners utilize equipment strong enough to break through extremely hard
Asphyxiant gas to detect asphyxiant gases in mines led to the Federal Mine Safety and Health Act of 1977 in the United States which established ventilation standards in which mines should be "...ventilated by a current of air containing not less than 19.5 volume per centum of oxygen, not more than 0.5 volume per centum of carbon dioxide..." Asphyxiant gas An asphyxiant gas is a nontoxic or minimally toxic gas which reduces or displaces the normal oxygen concentration in breathing air. Breathing of oxygen-depleted air can lead to death by asphyxiation (suffocation). Because asphyxiant gases are relatively inert and odorless, their presence