Canadian Occupational Safety

18 Canadian Occupational Safety www.cos-mag.com n May 22, 2014, Michael Bunz died while working alone at an oil battery in southeast Saskatchewan. The 38-year-old man from Wawota, Sask., sold chemicals to the oil industry and he regularly conducted testing at well sites. He left behind his wife and two daughters. The incident is still under investigation by the provincial occupational health and safety branch, so it is unclear exactly what happened, but the coroner's offi ce confi rmed hydrogen sulphide (H2S) was the cause of death. "I got a phone call from his boss that he was hurt, and he was gone," Kara Bunz told the CBC. "I got the autopsy report, so I know 100 per cent that it was H2S gas." H2S — also called sour gas, sewer gas and stink damp — is a highly toxic gas that occurs naturally in the earth in petroleum and natural gas. It is one of the most deadly occupational hazards in the oil and gas industry — too much H2S can kill a worker in a few seconds. Oil and gas workers are exposed to H2S most often during drilling and production of natural gas, crude oil and petroleum products. It is also found in refi neries, oil and gas wells, battery stations and pipelines. Truck drivers transporting fl uids that H2S has been dissolved into have some of the highest fatality rates for H2S. EXPOSURE LIMITS The eight-hour occupational exposure limit (OEL) for H2S in Alberta is 10 parts per million (ppm) and the ceil- ing is 15 ppm. In British Columbia., the OEL is a ceiling limit of 10 ppm. In Saskatchewan, the eight-hour average contamination limit is 10 ppm and the 15-minute limit is 15 ppm. At just 20 ppm, exposure to H2S can cause eye, nose, throat and lung irritation, digestive upset and loss of appetite. H2S levels of 100 ppm and higher are considered immediately dangerous to life and health, which is much lower than many other toxic gases. "H2S can be a lethal gas in very small quantities and that's why it attracts so much attention and so much caution," says Cameron MacGillivray, president and CEO of Enform, the safety association for the upstream oil and gas industry, headquartered in Calgary. "We're talking about very, very small concentrations presenting a signifi cant human health risk." Exposure of 200 ppm can cause major irritation of the nose, throat and lungs, along with headaches, nausea, vomiting and dizziness. Pulmonary edema (fl uid in the lungs) can also develop. Above 500 ppm, workers may expe- rience sudden collapse (knockdown), unconsciousness and death. "The big problem with H2S is it's a nerve gas; that's what's unusual about it. It affects the ability of the central nervous system and your body to use oxygen… and that can lead to unconsciousness and, ultimately, death," says Arliss Levine, safety consultant and trainer for Allstar Enviro Safety in Calgary. Workers who are exposed to concentrations above 500 ppm and survive may recover completely or suffer long-term health effects such as fatigue, anxiety, irritability or impaired learning and memory, according to Work Safe Alberta. Workers who experience knockdown have a greater chance of having permanent effects to the respiratory system such as By Amanda Silliker 1. EVACUATE • Get to a safe area immediately. • Move upwind if release is downwind of you. • Move crosswind if release is upwind of you. • Move to higher ground if possible. 2. ALARM • Call for help ("Man down"), sound bell, horn, whistle or call by radio. 3. ASSESS • Do a head count. • Consider other hazards. 4. PROTECT • Put on breathing apparatus before attempting rescue. 5. RESCUE • Remove victim to a safe area. 6. REVIVE • Apply CPR if necessary. 7. MEDICAL AID • Arrange transport of victim to medical aid. • Provide information to Emergency Medical Services (EMS). Source: Enform Hydrogen sulphide is one of the most deadly occupational hazards in oil and gas 7 -STEP H2S INITIAL RESPONSE STRATEGY Hydrogen O I L A N D G A S

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