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If a worker approached you with questions about how your control programs protect their health and safety, how would you answer them? You might tell the worker that the controls keep their exposure to a hazardous substance below the relevant occupational exposure limit, but could you explain why this OEL exists and what data it's based on?

"A lot of industrial hygienists do not have specific training in toxicology yet use occupational exposure limits as guidelines for acceptable exposure to the workroom population," said Nadia Moore, PhD, DABT, ATS, ERT, CIH. "And those occupational exposure limits are based on toxicological studies and principles." Understanding the foundations of toxicology leads to understanding the bases of occupational exposure limits, she explained. This will help occupational and environmental health and safety professionals "be able to communicate those types of concepts with the working population that they're protecting," Moore added.

Moore, who has many years of experience in conducting toxicological studies, performing risk assessments, and deriving OELs, is one of four instructors of an online course developed by AIHA's Toxicology Committee, titled "Fundamentals of Toxicology." This course was developed to help OEHS professionals "understand the fundamental principles of toxicology, bring a greater awareness to their practice, and have a greater appreciation of the toxicology data on which the OELs and other concepts rely," Moore said.

What to Expect from the Course

Moore, with her co-instructors Britt Weldon, PhD, David G. Dodge, DABT, CIH, and Angie Perez, PhD, CIH, deliver the online course as a series of four modules. The first module, taught by Moore, will introduce participants to foundational toxicology concepts, such as the dose-response curve, as well as common abbreviations used in the field. This information will help participants make sense of the rest of the course.

In the next module, Weldon will cover toxicokinetics and toxicodynamics. Toxicokinetics describes "how chemicals are absorbed and then distributed, metabolized, and excreted by the body," Moore explained. "That's important because some chemicals may be absorbed, distributed, and metabolized much more slowly than other chemicals. You may see a build-up over time of some chemicals, while other chemicals are excreted very rapidly."

"While toxicokinetics is how the material moves in and out of the body," she continued, "toxicodynamics is what happens once that chemical is in the body. What types of cells does it interfere with or interact with, and what types of adverse effects occur?"

After receiving this background, attendees will complete Perez and Dodge's modules on the derivation of OELs and the application of toxicology in emergency response. Although the course will be delivered asynchronously, lectures will be interspersed with quizzes to add an interactive element. Moreover, the modules will include case studies taken from the real world, which Moore hoped participants would find relevant to their work. "Although the course does include a theoretical background," she said, "in order to make it resilient among the attendees, it really needs to be practical in nature."

Overall, the course will give attendees "the tools to be able to answer potential questions regarding chemicals in the workplace," Moore said. If a worker asks how a given OEL will protect them, an OEHS professional who has taken the course should be able to tell them, in basic terms, what sort of health effects the OEL is intended to prevent and how toxicologists concluded that the OEL was necessary.

"I hope that attendees will have a greater appreciation of what an occupational exposure limit is based on and the types of data that form the basis for setting those levels," Moore said, "as well as a general appreciation for the toxicological principles."

Additional Information

This asynchronous course will take about 3.5 hours to complete, and participants will have 12 months from their purchase of the course to finish the modules. Early-career professionals and those preparing for their Certified Industrial Hygienist exams particularly may benefit from the basic toxicological knowledge the course imparts.

To learn more about the "Fundamentals of Toxicology" online course or to register, visit AIHA's website.