Results demonstrated a 90% decomposition rate.

Where: Naturally occurs in crude petroleum, natural gas, volcanic gas, hot springs. Also produced artificially in industrial activities such as food processing, coke oven and kraft paper mills. 

Dangers: Long term exposure can lead to convulsions, coma, brain or heart damage and even death. 

Prevention: Use exhaust and ventilation systems to filter out h2s levels, keep respiratory equipment at hand, and provide educational training to workers who are regularly exposed to h2s.