Firedamp is explosive at concentrations between 4% and 16%, with most violence at around 10%, and caused much loss of life in coal mines before the invention of the Davy lamp. Even after the safety lamps were brought into common use, firedamp explosions could still occur from sparks produced when coal contaminated with pyrites was struck with metal tools. The presence of coal dust in the air increased the risk of explosion with firedamp, and indeed could cause explosions itself.
The Tyneside coal mines in England had the deadly combination of bituminous coal contaminated with pyrites, and a great number of lives were lost in accidents due to firedamp explosions, including 102 dead at Wallsend in 1835. A continuous flame was produced at Whitehaven sometime before 1733, described as being "a yard wide and two yards long." The miners dealt with it by piping it to the outside.