Dangers of Hydrogen Sulphide Exposure

In an incident report by the Glasscock County Sheriff, Keith Burnett, through the Midland Reporter Telegram, an industrial accident left a 65-year-old man dead and three others in the hospital.
Johnny Mills, 65, died after he was exposed to hydrogen sulfide while working in an oil field. Mills and Steven Waters, 27, were on top of a tank battery around 9:20 a.m. Near Farm-to-Market Road 461 about 15 miles north of Garden City when they went to open a valve and were exposed to hydrogen sulfide gas, Burnett said. Waters had fallen off the tank when officials arrived, and Mills was discovered unconscious on top of the tank. Waters was airlifted to an Odessa hospital where he remained in stable condition late Monday, Burnett said. Mills was pronounced dead at 11:50 am that day.

Mike Moore, 48, and Ernie Hicks, age unknown, were on the ground during the incident and were transported via ambulance to Scenic Mountain Medical Center in Big Spring. Burnett said they would be held at the hospital overnight Monday for observation, but remained in stable condition.
Burnett said Mills’ death is the first to occur during an industrial incident this year, but said unfortunately with oil field activity increasing during recent years such incidents are not uncommon.
As explained by the OSHA (Occupational Health and Safety Administration) Fact Sheet, Hydrogen sulfide (H2S) is a colorless, flammable, extremely hazardous gas with a “rotten egg” smell. It occurs naturally in crude petroleum, natural gas, and hot springs. In addition, hydrogen sulfide is produced by bacterial breakdown of organic materials and human and animal wastes (e.g., sewage). Industrial activities that can produce the gas include petroleum/natural gas drilling and refining, wastewater treatment, coke ovens, tanneries, and kraft paper mills. Hydrogen sulfide can also exist as a liquid compressed gas.
Exposure to Hydrogen Sulfide (H2S) in gaseous or liquid form is a highly flammable substance and can result in life-threatening situations if not appropriately controlled. Hydrogen sulfide gas burns and produces other toxic vapors and gases, such as sulfur dioxide. In its liquid form, exposure can lead to severe frost bite. Workers are primarily exposed to hydrogen sulfide by breathing it.
Its effects depend on how much and for how long hydrogen sulfide (H2S) is inhaled. Prolonged exposure at 2-5 parts per million (ppm) may cause nausea, tearing of the eyes, headaches, loss of sleep and airway problems in some asthma patients. Where concentration level is between 700-1000 ppm, it leads to rapid unconsciousness, or immediate collapse within 1 to 2 breaths and death within minutes.
We therefore advise that you adhere to the standard permissible exposure limit of 20 ppm ceiling concentration and a peak exposure limit of 50 ppm for no more than 10 minutes. Prior to exposure, have a qualified person conduct air monitoring test. This will indicate whether fire or explosion precautions are necessary. Always ensure proper ventilation of the area. Workers should be equipped with proper protective, rescue and communication equipment. A self-contained breathing apparatus is required in spaces with a concentration higher than 100 ppm.
In conclusion, workers who must in such volatile environment must always insist on a standard respiratory protection program. This program must include proper respirator selection, fit testing, medical evaluations, and training. For more information on respiratory protection, click here