The first ethical principle for the practice of industrial hygiene, per AIHA, is that: Industrial hygienists shall practice their profession following recognized scientific principles with the realization that the lives, health, and well-being of people may depend upon their professional judgment.

This ethical principle must be viewed in many ways. First, anyone may call themselves an industrial hygienist and anyone may practice industrial hygiene. No license, certificate, formal education, or years of experience are required for someone to practice industrial hygiene in the United States. Whether IH is a profession, trade or practice is just semantics.

The term “industrial hygiene” is just semantics, too. IH is a broad and evolving concept. In 2020, the ABIH, that sponsors the CIH®, updated its mission to include: “The American Board of Industrial Hygiene is the premier credentialing organization for professions based on the science of evaluating, protecting, and enhancing the health, safety, and environment of people at work and in their communities.” Where are the limits on this mission?

When we consider the health, safety, and environment of people at work and in their communities, there may be few limits for CIH® practice. For example, ISO 45003:2021 Occupational health and safety management – Psychological health and safety at work – falls within the domain of a CIH®. But are psychosocial risks among people in the community, of which there are many triggers, such as when a neighbor plays music too loud and causes stress among other nearby neighbors, within the domain of a CIH? The concept of “people” requires further consideration, too. Each year, for example, there are about 2 million pregnant workers. Are “future children” of these workers “people” that deserve risk protection from a CIH®?

Professional judgment

The above discussion could be expanded ad nauseum. Arguably, however, whenever anyone determines by “scientific principles” and “science” (debatable terms as demonstrated by the politicization of Covid) that a workplace or community exposure to a chemical, physical, biological agent, psychosocial stress, or whatever, is safe, unsafe, or uncertain, then that person has rendered professional judgment.  Whether anyone trusts and follows the judgment is the critical point.

Professional judgment is on the rise among OHS pros for many reasons. Speed, efficiency, generalization of work, and cost savings over quantitative risk assessment methods being the primary reasons. All of my consulting work, for example, involves a large amount of professional judgment. It is impractical, or impossible, to quantify every exposure that I encounter onsite or discuss with clients. Good professional judgment, therefore, is the financial bread and butter of my business.  Your professional judgment success will likely define your career success, too.

Judgment under attack?

The “Judgment Day” article that appeared in the January 2014 issue of the AIHA’s Synergist placed IH professional judgment under intense scrutiny. The authors determined through literature review that initial exposure assessment judgment among IHs have a “mean accuracy of approximately 30 percent; in some cases, they are no more accurate than judgments based on random chance.” Is IH professional judgment really that poor?

Sandia National Laboratories (SNL), which supports the U.S. Department of Energy’s National Nuclear Security Administration, is one organization that scientifically evaluated its use of IH professional judgment. The Sandia Report, “Quantitative Exposure Assessment Professional Judgment Validation Study” (1) released July 2018, conducted retrospective quantitative exposure monitoring to validate 106 randomized IH professional judgments performed at SNL for acceptable breathing zone chemical exposures. The study evaluated 22 IHs at SNL, eight of whom did not hold the CIH® credential. Professional experience within the group ranged from 2-37 years, with an average experience of the group at 13 years. Exposure monitoring found all 106 samples were below applicable OELs, that validated use of IH professional judgment at SNL.

The Judgment Day article claiming the mean accuracy of IH professional judgment is approximately 30 percent to demonstrated 100 percent accuracy for IH professional judgment at SNL begs the key question: Why the difference? While the literature does not provide a clear answer, the answer likely rests with the amount of scientific training that each IH has acquired. Experience, while important, probably is less important than science knowledge. For example, 8 percent of the accurate IH professional judgments at SNL were made by IHs with less than three years of experience.  But all IHs at SNL must have adequate training in science before hire.

How much science training does an IH need?

The type and amount of science training necessary to become and hold the CIH® (there were only 6,940 practicing CIHs® as of the end of 2019) is specified by the ABIH. The same formula, however, cannot be applied to the many, likely tens-of-thousands, people that practice some aspect of IH. Again, IH is a very broad practice with many aspects and specialties such as chemical, engineering, radiation, toxicology, psychosocial, and acoustics, just to name a few.

From my experience, unless an IH has an academic year of inorganic chemistry followed by an academic year of organic chemistry, that supports a thorough understanding of chemical concepts such as molecular weight, boiling point, vapor pressure, and others, including an awareness of chemical reactions, coupled with coursework in ventilation engineering, they may have difficulty making accurate professional judgments for chemical exposures.

Each employer will determine how much science training an IH needs under their employment or hired as a consultant. SNL expects 100% accuracy in professional judgment for chemical exposures among their IHs. Therefore, IHs at SNL have a lot of science training.  If an employer can tolerate IH professional judgment “no more accurate than judgments based on random chance,” then little science training is necessary by the IH, and that is the employer’s choice.

Continuance of science training is the main way for anyone to improve accuracy for their IH professional judgments.  Another way to improve accuracy is to employ various exposure checklists, databases, and tools. AIHA’s Exposure Modeling Toolbox at ref. 2, available to anyone, is good source for this information.

Document professional judgments?

OSHA requires employers at 1910.1020 Access to exposure and medical records, to maintain a record of measurements e.g., air sampling or biological monitoring that determines worker exposure to toxic substances or harmful physical agents. IH professional judgments, however, are not addressed within 1910.1020. A record for each IH professional judgment may be needed by the employer or OHS pros for other reasons. Why and how to document IH professional judgments will be addressed in an upcoming best practices column.