Setting a Higher Standard: The Limitations of Regulatory Limits

Is a business’ safety culture a success if it simply follows the letter of the law and avoids government fines?

• By Luis F. Pieretti
• Oct 01, 2019

Should OSHA be the gold standard for workplace safety? Is a business’ safety culture a success if it simply follows the letter of the law and avoids government fines? Should employee health and safety be a goal beyond compliance with a legal standard? For those of us working in the safety and health field, we know the answers for those questions.

For regulatory purposes, OSHA has its permissible exposure limits (PELs) for less than 500 substances. But when it comes to employee exposure to chemicals’ airborne contaminants, most safety and health professionals usually use the recommended exposure limits (RELs) from the CDC’s National Institute for Occupational Safety and Health (NIOSH) and/or the threshold limit values (TLVs) from the American Conference of Governmental Industrial Hygienists (ACGIH).

So, what is the difference? The RELs and TLVs are updated based on sound industrial hygiene practice and data available from epidemiological and toxicological studies. These guidelines are updated as the information is available but are not enforceable by law. Only OSHA’s PELs are enforceable by law. What people outside the occupational safety and health field don’t understand is that most of OSHA’s PELs in 29 CFR 1910.1000 Table Z-1 were the adopted ACGIH’s threshold limit values from 1968. These are based in toxicological and epidemiological knowledge published prior to that date. The permissible exposure limits contained in 29 CFR 1910.1000 Table Z-2 were mostly adopted from ANSI standards dating from 1966-1971.

When employers understand the limitations of OSHA’s permissible exposure limits, they usually ask “why doesn’t OSHA just update them?” Well, OSHA tried to update all the PELs in 1989. During that process, OSHA lowered the permissible exposure limits for 212 chemicals and added new limits for 164 additional chemicals. But in 1992, this effort was vacated by the Eleventh Circuit Court of Appeals because it found that OSHA had not made sufficiently detailed findings that each new PEL would eliminate significant risk and would be feasible in each industry in which the chemical was used.

Another obstacle is the number of years it takes for OSHA’s rulemaking process. For example, OSHA had been working to create an occupational standard for respirable crystalline silica since 2003 and didn’t introduce the new standard until 2017. Even now, OSHA could revise the standard and is seeking public comment until October 15, 2019.

Before adopting an occupational safety and health standard, OSHA needs to show that a significant risk exists. Once this information is available, OSHA needs to show how the new standard will significantly lower the significant risk and the technological and economic feasibility of the proposed standard. This is a resource-intensive process. Since 1971, OSHA has been able to establish or update permissible exposure limits for only about 30 chemicals.

As stated previously, permissible exposure limits are available for fewer than 500 substances. Non-regulatory guidelines should be used as a supplement to regulatory limits since there are thousands of chemicals used in manufacturing processes today.

Many safety professionals have been asked how OSHA handles situations where an employee is exposed to a chemical substance with no published OSHA permissible exposure limit (PEL). OSHA recognizes that the PELs listed in 29 CFR 1910.1000 tables are outdated, but as already noted, the process of updating a standard can take a while.

However, this does not mean that OSHA has their hands tied in these situations. On November 2, 2018, OSHA sent a memorandum to all regional administrators regarding its enforcement policy for respiratory hazards not covered by OSHA permissible exposures limits. OSHA can cite an employer under the General Duty Clause of the OSH Act (“Each employer shall furnish to each of his employees’ employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees.”) under the following circumstances:

1. The employer failed to keep the workplace free of a hazard to which employees of that employer were exposed. Evidence may include air sampling, witness statements, documentation of personal protective equipment, and evidence that continuous employee exposure at the levels measured (not a one-time only) could reasonably occur. If exposed employees are using respiratory protection and all the elements of the respiratory protection program are implemented, then the likelihood of being cited under the general duty clause diminishes.

2. The hazard was recognized. Evidence may include employee complaints, OSHA 300 logs, consultant reports, information from safety data sheets, information provided by industry or trade associations, or information from other federal, state, or local government agencies.

3. The hazard was causing or was likely to cause death or serious physical harm. This requirement may include information from industry-related, peer-reviewed studies or an expert.

4. There was a feasible and useful method to correct the hazard. Evidence may include information from the safety data sheet and/ or other NIOSH studies.

This means that in order to be cited under the general duty clause, all elements must be present and documented. The memorandum goes on to say that citations under the general duty clause should not be based solely upon evidence that measured concentrations were above a threshold limit value from the ACGIH, a recommended limit value from NIOSH, or documentation that the air contaminant is a carcinogen. If all elements are not met, OSHA should send a hazard alert letter to the employer instead that provides recommendations for exposure control.

Going back to silica: the prior permissible exposure limit was not a concentration number, but rather, the product of a formula based on the amount of silica detected on the collected sample. NIOSH established an exposure level of 50 µg/m3 in its 1974 recommendation (that exposure limit is now OSHA’s current permissible exposure limit). The challenge of whether to use regulatory limits or guidelines is not limited to chemicals; the same can be said about noise measurements. Measurements for OSHA compliance require an exchange rate of 5 decibels, but ACGIH and NIOSH recommend using an exchange rate of 3 decibels. Measurements made with a lower exchange rate will yield higher results; therefore, the results can be considered more restrictive than measurements made for OSHA compliance.

This article originally appeared in the October 2019 issue of Occupational Health & Safety.