Tarenni Colliery 1858, when the Primrose Colliery was owned by Morgan and Lewis, fumes of an engine boiler suffocated 14 men and boys, and 7 horses. According to HM Inspectorate of Mines and Quarries data, outside the Gwendraeth valley, Tarenni Colliery had the highest set of recorded incidents for coal damp and methane gas explosions. In total during its production lifetime, there were six outbursts in which three men lost their lives: one on 12 December 1914; two on 17 February 1941. On 1 November 1909, water from the abandoned Ynysgeinon pit caused the death of five miners at Tarenni No.2. On
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