RHP Risk Management’s Human Health Risk Sciences team, Ashish Jachak, PhD, MBA; Debra A. Kaden, PhD, ATS, and Melanie Buser, PhD, DABT, MPH attended the 65th Annual Society of Toxicology (SOT) meeting, where they heard about various trending topics in the toxicology field including new approach methodologies (NAMs), read-across, carcinogens with threshold mechanisms, monomers, and science policy, among various others. The SOT conference is attended by industry leaders in toxicology, including those engaged in carcinogenesis, exposure, occupational and public health, regulatory and safety evaluation, and risk assessment.
RHP’s experts featured their recent research: Melanie Buser, PhD, DABT, MPH presented on “Derivation of an NSRL for Vinyl Acetate” where she discussed RHP’s approach to deriving a No Significant Risk Level (NSRL) for vinyl acetate, and Ashish Jachak, PhD, MBA, presented research on “Chemical Additive Leaching and Human Exposure Potential from PVC and PE Microplastics in U.S. Drinking Water” where he discussed the occurrence of PVC and PE microplastics in U.S. drinking water and the leaching potentials of additives. Below we share some of our takeaways from the meeting.
New Approach Methodologies (NAMs)
New Approach Methodologies (NAMs) in toxicology are the use of innovative, non-animal technologies, including in vitro assays, in silico computer modeling, and organ-on-a-chip systems, designed to replace or reduce animal testing. These methods can provide faster, less expensive, human-relevant study assessments for chemicals and drugs. While NAMs are not new, they are working their way into more areas of toxicology and regulatory assessments. Increasing reliance on NAMs is shifting the current landscape of toxicology; SOT provided an opportunity to gain insight into translating NAM-based evidence into valid, decision-ready conclusions.
Read-across
Read-across included examining other chemicals which may have similar structure and function to fill in data gaps to avoid costly assays, especially in cancer assessment. While read-across has been used successfully in Europe as part of the REACH program, the technique is gaining traction in the U.S as well. For example, read-across is being used in safety dossiers to petition avoiding a 2-year bioassay for cancer assessment. This method was discussed in the context of pharmaceuticals, herbicides, pesticides, and the Toxic Substances Control Act (TSCA).
Carcinogens with Threshold Mechanisms
Traditionally, the default for cancer risk assessments is a genotoxic mechanism with no safe threshold. However, many presenters discussed carcinogens which are believed to have threshold mechanisms for cancer causation. These are agents that may cause cancer at higher doses, but not at lower levels of exposure. Such thresholds may occur if there is a biological mechanism that is protective of cancer (e.g., metabolism, DNA repair) which may be saturated, or if other processes (e.g., inflammation, cell proliferation) that underlie the cancer process for that agent.
Science Policy
When does science become policy? Science policy includes decisions, laws and regulations that determine funding and the application of research to serve public interests. The process of deriving health-based guidance values (HBGVs) is considered a science-informed policy decision, not solely a science decision. It is essential to understand the policy objectives of regulators in addition to the science in order to have meaningful conversations.
Taken together, the program reflects a toxicology landscape that is becoming more data rich yet also more complex, requiring improved integration of science, regulation, and communication to support credible and actionable decision-making.
About RHP Risk Management
RHP Risk Management is an environmental and occupational health consulting firm of scientists, toxicologists, public health professionals and risk assessors that cover practices including environmental engineering, industrial hygiene, exposure science, and human health interaction and risk assessment.
RHP works with clients to develop solutions to their most pressing concerns. Understanding exposures and risks through a grounding in a sound, defensible, state-of-the-art scientific approach gives our clients peace of mind. Empowered by a comprehensive understanding of exposures we can provide clients with reliable, strong data and tools to recognize unseen business and liability risks, manage known risks and mitigate, target areas for control systems, comply with regulations, and be better braced for regulatory or liability actions.
Ashish Jachak, Ph.D., MBA, principal toxicologist at RHP Risk Management Inc.
Debra A. Kaden, PhD, ATS, principal toxicologist at RHP Risk Management Inc.
Melanie Buser, Ph.D., DABT, MPH, senior associate at RHP Risk Management Inc.