H2S: The danger of this “sour” gas silent killer
Hydrogen Sulfide (H2S) is really prevalent here in the south/southwest, but also is becoming more prevalent in other areas where oil and gas exploration is taking hold in light of the U.S. trying to break our dependence on foreign oil reserves. Examples are Pennsylvania, North Dakota, etc. Those fields which were previously "sweet"....having very little sour gas, if any, have turned around and are becoming much more sour. This process is expected in our industry, but it only goes one way.....from marginally sour to very sour. Never the reverse.
H2S is known as the "silent killer". It's an insidious and invisible gas which smells a bit like rotten eggs at low concentrations. It quickly paralyzes the olfactory nerves (sense of smell) at about 100 part per million (ppm). Many times, upon investigation of major incidents/fatalities, the concentration didn't go from zero to toxic, but simply hit the victim with a deadly concentration immediately .
Recently (2/1/2010) the American Conference of Industrial Hygienists (ACGIH) reduced the Threshold Limit Value / Time Weighted Average (TLV/TWA) of H2S from 10 ppm to 1 ppm and the Short Term Exposure Limit (STEL) from 15 ppm to 5 ppm. The committee responsible for the ASSE/ANSI Z390.1-2006 Accepted Practices for Hydrogen Sulfide (H2S) Training Programs, which I chair, argued against this change since it was initially announced back in the early 90s. We feel that the reduction was too much, too quickly. According to the rationale for the change, there wasn't much evidence that the higher TLV/TWA was actually harmful to the workers in our industry. We've been working in levels below the 'then TLV' of 10 ppm for many, many years with relatively low incidence of reported injuries/illnesses.
The ambient levels of H2S in the atmosphere, particularly around some fields like McCamey and Andrews, TX, Hobbs, NM, etc., are consistently around 1ppm-3ppm, and excursions from 3 to 5 ppm+ are not uncommon.
Our main challenges within the industry are training workers to follow the current safe work practices which have been developed over the years. We can work safely in higher levels of the gas, but we have to insure that we follow those practices. It becomes a matter of training and then follow up to ensure that the training is correct in its content and conduct. That's where I come in. My life's passion has been to doggedly pursue this training issue, making sure that the training that is conducted is in accordance with the Z390.1, and that no training is cut short or skipped in the interest of time and/or production or in the interest of saving a few dollars.
We find sour gas primarily in the oil and gas exploration, production and refinery operations, paper mills, landfills, sanitary sewers, animal blood processing, excavations, etc. The list goes on and on. And a major concern is that when someone is knocked down by the gas, well-intended would-be rescuers rush in to help that downed person, only to become victims themselves. We have to train them repeatedly to take care of themselves first by donning a self-contained breathing apparatus then attempt the rescue.
H2S Master Trainers? We came up with this idea about 6 years ago. The driving thought was that I'm not getting any younger. I'll turn 68 next month, but the end is not in sight regarding my involvement with this training effort. Our workers are killed and injured at an alarming rate. As you well know, a single fatality is one too many, particularly if it's a family member, a close friend, or a co-worker. That fact alone demonstrates that there are more than enough training opportunities to go around in this field. I have actually been criticized by a safety & health professional for making more certified/qualified H2S trainers. He said that I was "messing up his retirement". I don't see it that way. According to my own spreadsheet, I have trained 1,804 H2S instructors in my career, as of this week. But I need to do more. That is the "why" of the H2S Master Trainer. I developed a 5-day course essentially to replace myself in this business. I'm not selfish with this business; there is a definite need for more H2S Master Trainers throughout the world.
The 5-day course consists of the first 2 days dedicated to adult education and training techniques. The final 3 days are focused on the technical aspects of hydrogen sulfide. After the first 6 years of conducting this 5-day course just once each year, we are making some changes. My wife holds a PhD in Curriculum and Instruction, and I have my certification from NESHTA/BCSP for the CET. We are re-designing the first 2-day adult education session to insure that it is compliant with the ASSE/ANSI Z490.1-2009 Criteria for Accepted Practices in Safety, Health and Environmental Training. I am the current Vice chair for that committee and have a vested interest to insure that any training that I'm associated with follows those guidelines.
We have certified 56 H2S Master Trainers to date, with a significant number of those coming here from the Middle East to receive their training. They have a tremendous problem there with H2S and have reached out for this particular training. And, yes, I am trying to work myself out of a job.