Despite 350,000 registered chemicals, <1% have safety data; industrial hygienists must make decisions in the face of uncertainty. This paper reimagines the Hierarchy of Controls framework (elimination, substitution, engineering controls, administration controls, and personal protective equipment) and the established industrial hygiene framework for hazard anticipation, recognition, evaluation, control, and confirmation of hazard elimination to account for the multiple chemical spaces, both at work and in personal life, in which a worker may be exposed to chemicals across the chemical multiverse, defined as the multiple chemical spaces, each defined by a unique set of descriptors that workers encounter, and the uncertainty related to the potential health effects of these emerging chemicals and technologies. This requires the adaptation of previously developed tools, exposure assessment strategies, and frameworks to manage unknown chemical exposures, and it suggests that manufacturers developing new chemicals, materials, or emerging technologies should be more explicitly encouraged to adopt a precautionary principle approach, examining the entire life cycle of a chemical or material before introducing it into commerce, to reduce potential adverse exposures from downstream usage of the chemical or material, and developing exposure monitoring methods for occupational health professionals to use to monitor worker health. This is the first paper to systematically merge the chemical multiverse concept into occupational health frameworks, providing a new holistic lens for industrial hygienists to protect workers and consumers while at the same time reinforcing the importance of stakeholder engagement and a shift to an anticipatory risk management approach to the full life cycle of chemicals, materials, and products to promote prevention of occupational illness.
Houlroyd et al. (Sun,) studied this question.