We cordially invite you to submit an oral or poster abstract for presentation at this important event.  Join us as we bring together leading experts, researchers, and practitioners to advance knowledge and solutions in the field of occupational and environmental health.

DEADLINE: January 13, 2027, 11:59 p.m. ET

Exposure limits play a pivotal role in many aspects of occupational, environmental health, and safety (OEHS) practice. At the same time, in the United States (U.S.) and worldwide, the community of OEHS professionals faces significant challenges in navigating a landscape that lacks harmonized guidance on the derivation process and variable utilization of exposure limits. To further complicate this situation, published limits, set by independent and regulatory agencies, exist only for a small fraction of environmental and workplace agents. In contrast, for many of the agents used in the highest volumes, there are often several exposure limits that can vary in concentration and can be separated by order of magnitude or more. Advancing the development of exposure limit science and policy may help address these challenges. 

For early-generation exposure limits, systematic and documented principles of their determination were never established, and many of them are not fully health-based. Limit setting has evolved, leading to a foundational approach that is commonly employed. The basic elements of identifying relevant adverse effects for hazard characterization, conducting dose-response analyses to identify a point of departure at a relevant response rate, and applying methods to address biological variability and data uncertainty remain the foundation for exposure limit derivation. New quantitation tools and better assessment of biological response have improved these basic steps, including extrapolations across species, dose routes, exposure durations, and observational response rates to target risk ranges (i.e., low-dose extrapolation). 

Formal exposure limit derivation methods and policy acceptance of these methods have advanced. However, in many cases, quantitative risk estimation at the exposure limit value and alignment on key policy choices related to acceptable risk have not been fully addressed. For example, for many decades, regulatory agencies in the U.S. and worldwide applied a so-called “linear non-threshold” (LNT) model of the dose-response relationships for carcinogens, implying that virtually any dose of the agent would cause at least some increase of cancer risk. This position has been criticized as not fully substantiated for the data ranges when exposure is low and predicted cancer risk is a minuscule fraction of baseline levels in populations. Additional biological basis for response has also advanced, suggesting that alternative dose-response estimation methods are likely to be appropriate (even for many carcinogens). This policy shift is especially important in the context of recent Executive Order 14300 from the U.S. administration, which required abandoning of the LNT model and the ALARA (as low as reasonably achievable) principle for radiation protection. In particular, the principle of acceptable risk and implications of other policy choices (e.g., definitions of adversity and risk, default assumptions for uncertainty, risk calculation methods, among others) should receive better scientific support.  

The symposium will discuss several essential aspects of the derivation and implementation of exposure standards using the latest advances in science. Topics of interest include:  

• The role of and implementation policies for exposure limits for OEHS practice and protection of workers and communities;
• General principles of establishing and harmonizing environmental and occupational exposure limits based on epidemiological, toxicological, and risk assessment studies, with consideration of scientific and mathematical uncertainties;
• Principles for evidence integration in exposure limit setting, including approaches to use toxicological mode of action data in the context of complex data sets and Exploratory Data Analysis methodology;
• Application of emerging test methods such as new approach methodologies and other modern toxicological practices, relevant for adverse effect and exposure benchmarking;
• Uses of Bayesian analysis, benchmark dose modeling, artificial intelligence, and other advanced tools in risk assessment and OEHS practice;
• Methods for integration of toxicokinetic and toxicodynamic data in limit setting, including quantitative procedures that consider different exposure scenarios.
• Advances in low-dose modeling for carcinogens and other biological responses;
• Tools for estimating exposure thresholds in epidemiology and toxicology: how to determine a “safe level” for carcinogenic and non-carcinogenic substances;
• Exposure limit and risk estimation in the context of cumulative exposure and possible interaction between chemicals or other factors;
• Policy needs for determining an “acceptable risk” level: how societal risk benchmarks should be evaluated and established in parallel with changing societal expectations;
• Case studies on alternative limit-setting frameworks, including contrasting the TSCA experience relative to traditional limit paradigms, as well as feasibility and practical applicability of various exposure limits;
• Case studies for recent challenging assessments such as for asbestos, ethylene oxide, methylene chloride, formaldehyde, silica, and others.

The symposium will present the scientific research and case studies most relevant for the OEHS professionals, regulators, industries, and all interested parties, in an attempt to develop a dialogue that would systematize and harmonize current policy on exposure limits.    

Join us in advancing occupational health by sharing your latest research, technological advancements, and practical insights!
 

Symposium Steering Committee: 
 

• Andrey Korchevskiy, PhD, DABT, CIH, FAIHA
• Andy Maier, PhD, CIH, DABT
• Robert Skoglund, PhD, DABT, CIH, CPPS
• Michele Twilley, DrPH, CIH