Page 38 - Occupational Health & Safety, October 2017

INDUSTRIAL HYGIENE
Have Stakeholders Kept Pace with Lowered TLVs and RELs?
Why is there so much comfort in the status quo when the people who need the protection of these products require so much more?
BY DAVE WAGNER
Over the last several years, organizations such as the American Conference of Gov- ernmental Industrial Hygienists (ACGIH) have lowered their recommendations for
exposure limits on a number of common hazardous gases. For example, the ACGIH dramatically lowered the Threshold Limit Value (TLV) for both hydrogen sulfide and sulfur dioxide. In similar fashion, the ACGIH has named in its 2017 Notice of Intended Changes list other common gases, such as chlorine, chlorine dioxide, and phosphine, among its targets for adjustments to the exposure limits.
Let’s get this straight. This is not an editorial rant against the practices of the ACGIH. The plain and simple truth is that the ACGIH makes recommen- dations based on a thorough review of scientific evidence regarding what exposure levels constitute a threat to worker health and safety. Whether or not it is practical for systems to detect various compounds at the exposure limits does not fall within the scope of the ACGIH. This is a discussion on how equip- ment manufacturers and the industrial hygiene and safety community are addressing the need to detect and monitor toxic gases at ever decreasing levels. It is the reaction of these stakeholders that I find the most puzzling and frustrating.
Manufacturers of portable gas monitors, the type of equipment used to detect toxic gases in industrial hygiene and safety applications, are held hostage by technology. Although they would certainly ar- gue this, over the last 30 years, the technology of- fered by gas sensor manufacturers has not changed much. The same basic electrochemical sensors used to detect toxic gases 30 years ago are still used today. Sure, the sensors have gotten much smaller, allow-
Regardless of the fact that the ACGIH TLV recommendations do not represent regulatory standards, many companies are compelled to adopt these values into their safety and industrial hygiene programs.
ing manufacturers to build smaller instruments, but the chemistry is the same old, same old. One would think that over three decades, sensor researchers and developers would be able to make improvements in technology that would result in products that pro- vide detection of gases at much lower concentra- tions, with much greater stability and accuracy. But this is not the case. Why is there so much comfort in the status quo when the people who need the protec- tion of these products require so much more? (By the way, I am one of the said instrument manufacturers; guilty as charged.)
Regardless of the fact that the ACGIH TLV rec- ommendations do not represent regulatory standards, many companies are compelled to adopt these values into their safety and industrial hygiene programs. Industrial hygiene and safety professionals who are responsible for the health and welfare of employees know that controlling exposures or monitoring sub- stances at these levels may not be practical. There is a realistic fear that a worker who becomes injured or ill, and believes that it is the result of an exposure to a hazardous substance, will retain a very litigious at- torney who can present undeniable evidence that the ACGIH recognizes and publishes guidelines saying that exposures above the recommended levels repre-
34 Occupational Health & Safety | OCTOBER 2017
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