Most accidents are preventable.
The problem with oilfield accidents it that they can be lethal.
Two Barton County men died of asphyxiation Monday from the presence of hydrogen sulfide gas, a by-product from the production of oil and natural gas. Hydrogen sulfide causes respiratory paralysis and is highly toxic.
Dave McEndarffer has worked in the gas detection industry for 28 years. He works with RKI Instruments Inc., a gas detection company in Overland Park.
“We are all just sick to hear about the tragedy that took the lives of Mr. Myers and Mr. Hoffman,” he said. “This could have so easily been avoided.”
McEndarffer said encountering hydrogen sulfide gas is a extremely dangerous situation. He has read reports of fatal accidents when workers did not turn on their safety monitors or they forgot them in their vehicle.
Signage about a potentially dangerous place is helpful and employees who carry monitoring equipment insures a measure of safety.
“The only full protection is provided by a self contained breathing apparatus,” he said.
He said half of the deaths involve someone attempting to help a comrade out.
“The only way you can prevent someone from the natural instinct of helping someone is with education and training,” he said.
Hydrogen sulfide or H2S is characteristically described as smelling like rotten eggs. It is the byproduct of the breakdown of organic matter. That is why we smell it in our sewers from time-to-time. Oil and natural gas are fossil fuels, developing from old swamps and forests millions of years ago.
“As we know, H2S can be extremely dangerous and we can not depend on our own senses to alert us of the danger,” McEndartfer said. “Please take proper care to arm yourself and your facility with detection equipment that will alert you to the presence of H2S before it becomes life threatening.”
Since vegetation is organic, H2S can be prevalent. In fact, natural gas can contain up to 90 percent H2S. H2S is extremely toxic and was even used as a chemical warfare agent in World War I.
“One tricky aspect of H2S is that it can be smelled in lower concentrations but not as the amount increases,” McEndarffer said. “This is due to a phenomenon known as olfactory fatigue: the smelling sensors in our noses temporally deaden. This sometimes leads to a false sense of security.”
McEndarffer said people tend to believe that they will know if the gas is present because they will be able to smell it. H2S though, is easy to detect with the proper equipment.
He said portable devices that can be worn or “fixed” devices that can be permanently installed readily alerts to the presence of H2S before it becomes a danger.
Going into an enclosed space in inherently dangerous. An interior warning system would’ve prevented the tragedy.
“In the instance of this Claflin saltwater disposal site, a sensor mounted on the inside of the structure with a strobe light and horn on the outside would have provided warning before anyone even got out of their truck,” he said.
Since H2S is heavier than air, so, in the absence of wind, will pool towards the ground. There have even been cases that cattle standing in low spots in a pasture have been overcome by the effects of H2S.
Hydrogen sulfide, like many toxics gases, is measured in a ratio known as parts per million or ppm. To give context to this idea, 1ppm is 32 seconds out of a year.
Following shows some typical responses in a ppm range:
•.00047 ppm — H2S can be smelled
• 10 ppm H2S is the permissible exposure limit (PEL) allowed by OSHA (Occupational Safety and Health Administration)
• 50 to 100 ppm H2S — eye damage can occur
• 100 ppm H2S — olfactory fatigue occurs and it can no longer be smelled
• 320 ppm H2S — possibility of death
• 800 ppm H2S — death in 5 minutes
• 1,000 ppm H2S — death can occur with a single breath
RKI is partnered with Riken Keiki Co. Ltd., the world leader in gas detection and sensor technologies. Riken has sold more than 800,000 portable and fixed gas monitors worldwide with annual sales exceeding $220 million.