This week I was more than surprised to learn that not everyone uses the most up-to-date NIOSH IDLH values when deciding on their respiratory protection needs. This was brought to my attention after a SAFTENG member contacted me about my 2012 article “What type of respirator do I need?”. This safety professional had downloaded a document from one of, if not the the top, respirator companies in the world and began working through the Maximum Use Concentration (MUC) formula to determine the type of respirator his/her employees would need to be wearing to be adequately protected. When he/she was done they noticed their numbers differed from those I used in my worked examples in my article. When I responded that Chlorine’s IDLH is not 30 ppm, that it is 10 ppm you can imagine their confusion.
The confusion stems from the respirator company’s “Respirator Selection Guide” (I am not naming this company) which contains a table that provides a lot of the exposure data needed to establish the level of respiratory protection needed. This “guide” is dated 2015; however, it provides IDLH values that are 20+ years old! I only checked the chemicals that he/she had worked their MUC numbers on and found that Chlorine, Chlorine Dioxide, and Anhydrous Ammonia all stated their previous IDLH values of 30 ppm, 10 ppm, and 500 ppm respectively. I was more than stunned that this company would choose to update their “guide” in 2015 and not use the most recent NIOSH IDLH values. So much that I spent that afternoon trying to contact the right people in the company to inquire why they would do such a thing and how this old data was putting their customers at some serious risks.
The company acknowledged their use of the older data and stated it was supported by a 1998 OSHA Respirator Q&A Document that says:
Q. There are various published and sometimes conflicting IDLH limits. What levels will OSHA use for enforcement purposes?(FR p.1185)
A. OSHA has not established its own set of IDLH values. OSHA considers an atmosphere to be IDLH when it poses an immediate threat to life, could cause irreversible adverse health effects, or could impair an employee’s ability to escape. The 1990 recommended IDLH values found in the NIOSH Pocket Guide to Chemical Hazards may be used to support OSHA enforcement action. An employer may show however that another source of IDLH values is valid and then may rely on such a source.
Once again I was shocked that this company which I once considered to be a world-class provider of PPE (especially respirators) would consciously make a safety decision based on a single Q&A in a 1998 OSHA document merely because it is “legal” and “OSHA still has the document on their site”.
So here is the question I want to know your thoughts on…
- What IDLH data do you use to establish respirator limits within your program?
- Do you use the IDLH data from the early 1990’s or NIOSH’s most up-to-date data?
This is a serious matter! Using the old data vs. the up-to-date NIOSH data tells us we can wear a full-face APR in 30 ppm atm of Chlorine (CL2) or 500 ppm of Anhydrous Ammonia (NH3). For chlorine that is 3X’s the amount that the up-to-date NIOSH data establishes!
So I guess we need to be cautious as to where we get our safety data from (I never thought in my career I would be saying that about this company!). Be careful when your downloading “guides” from companies that sell products and always double check your work with a friend or colleague. And remember, OSHA’s Maximum Use Concentration (MUC) formula ONLY works when the atmosphere is BELOW the IDLH values.
1910.134(d)(3)(i)(B)(2) Employers must not apply MUCs to conditions that are immediately dangerous to life or health (IDLH); instead, they must use respirators listed for IDLH conditions in paragraph (d)(2) of this standard.
So it matters a lot which IDLH value(s) are used in our respirator programs – it matters to the point that it is LIFE and DEATH, especially when we’re talking about emergency response use in Immediately Dangerous To Life or Health (IDLH) atmospheres!