Gradient announces seven employees promoted to Principal Scientist and Managing Scientist in 2025.
Chase Butler is promoted to Managing Scientist: Ms. Butler is a chemist at Gradient with experience in designing sampling plans and testing protocols, assessing data quality, and interpreting data to support the fulfillment of various regulatory obligations.
Mary Hixon is promoted to Managing Scientist: Dr. Hixon is experienced in reproductive and developmental toxicology.
Naomi Slagowski is promoted to Managing Scientist: Ms. Slagowski is an environmental engineer at Gradient specializing in database management and Geographic Information Systems (GIS).
Steven Boomhower is promoted to Principal Scientist: Dr. Boomhower is a toxicologist at Gradient with specialties in metals toxicology, neurotoxicology, and human health risk assessment.
Charlotte Marsh is promoted to Principal Scientist: Ms. Marsh is a toxicologist at Gradient specializing in product stewardship, human health risk assessment, and global chemical compliance.
James Rice is promoted to Principal Scientist: Dr. Rice is an environmental scientist at Gradient specializing in contaminant transport and source identification, read-across assessment, and the evaluation of organic compound contaminants.
Meghna Swamy is promoted to Principal Scientist: Ms. Swamy is an environmental engineer at Gradient with expertise in the areas of contaminant fate and transport, source evaluation, risk-based remediation, and environmental cost liability/allocation.
Here is wishing them the best in their new leadership roles.
In this issue of Trends, we provide several articles on the topic of benzene, a well-studied substance for which there continues to be advances in understanding potential exposures and health risks – that is to say, “what is old is new again.”
Our first article discusses occupational exposure limits (OELs) for benzene and the most recent reduction of its OEL by the American Conference of Governmental Industrial Hygienists (ACGIH). The second article explores potential health effects of long-term exposure to benzene. The third article and related chart highlight how the method used to test consumer products for benzene levels can impact results.
Gradient contributors to this Trends issue include David Dodge, M.S., DABT, CIH; Robyn Prueitt, Ph.D., DABT; and Carrie Tuit, Ph.D.
Articles:
Gradient scientists recently published an article evaluating the available research on dermal absorption of PFOA and recommend provisional values for exposure to PFOA in water or soil. This analysis may be relevant to certain other PFAS in other exposure media, such as consumer products.
The article, “Evaluating Dermal Absorption of Perfluorooctanoic Acid (PFOA) and Implications for Other Per- and Polyfluoroalkyl Substances (PFAS)” was published in the peer-reviewed journal Regulatory Toxicology and Pharmacology. Gradient scientists evaluated the available studies quantifying the rate and extent of dermal absorption of PFOA, a PFAS chemical that has been used to make products resistant to water, heat, and stains. This study advances the scientific understanding of dermal exposure to PFAS and is the first publication of its type.
The Gradient authors evaluated the reliability and physiological relevance of the limited number of studies directly measuring dermal absorption kinetics of PFOA in human skin. Further, the authors assessed whether the reported kinetic parameters were measured under appropriate conditions relevant to typical environmental exposures in humans (for example, using appropriate doses, solvents, experimental pH). From this evaluation, the authors identified the most appropriate values for use as absorption factors to estimate dermal exposures to PFOA from soil and water. These values are considered provisional for use in PFOA soil and water exposure assessments until more data become available.
By applying the recommended absorption factors, the Gradient authors estimated PFOA exposures from soil and water in children via both dermal and ingestion routes. Overall, results from this study indicate low dermal absorption of PFOA from soil and water compared to the ingestion pathway. The Gradient authors conclude that low dermal absorption is likely for other PFAS with similar physicochemical properties to PFOA (for example, chain length and functional group composition). These findings, and the recommended dermal absorption factors, can be considered for estimates of dermal absorption for PFAS with similar characteristics in other exposure media. For example, this study could be of use in estimating dermal absorption of certain PFAS from consumer products, such as textiles, cosmetics, and personal care products.
Read the article here.
If you have any questions regarding the article, please contact:
Andrew Yeh, Ph.D., DABT
Senior Toxicologist
Andrew.Yeh@gradientcorp.com
Robyn Prueitt, Ph.D., DABT
Principal
Robyn.Prueitt@gradientcorp.com
Barbara Beck, Ph.D., DABT, ATS, AAAS Fellow
Principal
Barbara.Beck@gradientcorp.com
Gradient is presenting at the Society of Risk Analysis (SRA) 2024 Annual Meeting, taking place December 8-12, 2024, in Austin, Texas.
Dr. Tom Lewandowski was featured recently in Inside EPA’s Inside TSCA, commenting on the contributions industry can make to help improve US EPA’s approach to alternatives assessment under TSCA.
Dr. Tom Lewandowski was featured in the November 20, 2024, edition of Inside EPA’s Inside TSCA, which provides news and analysis on the Toxic Substances Control Act (TSCA). The article summarizes a webinar co-presented with lawyer Sarah Amick of the law firm Wiley Rein on the status of alternatives assessment under different regulatory programs. In particular, the article addresses some concerns that US EPA’s TSCA process has failed to fully analyze and identify suitable alternatives for some chemicals undergoing regulatory review. The article notes that industry groups are challenging TSCA assessments, stating that the US EPA’s current approach to alternatives assessment merely scratches the surface in determining if alternatives for a certain chemical “are available,” leaving a need for more comprehensive information regarding the suitability of an alternative as an effective substitute for a chemical’s various uses.
Dr. Lewandowski highlighted alternatives assessment requirements and programs under TSCA and in states such as California and Washington, and emphasized the benefits of industry in leading, or at least providing technical input on, regulatory-driven alternatives assessments. Responding to a question from Inside TSCA, he stated, “greater attention on whether an alternative can actually perform is going to be worthwhile and that’s where industry has a lot to contribute . . . especially for complex products, or products with complex uses. The folks in industry are the ones that have the knowledge about whether something works and why, right? I think that’s where the EPA process could be improved, to get that sort of input on the performance side of things.”
Read the article here.
For more information on Gradient’s alternatives assessment and TSCA services, please reach out to Gradient.
Contact:
Tom Lewandowski, Ph.D., DABT, ERT, ATS
Principal
Tom.Lewandowski@gradientcorp.com
Dr. Alex Gauthier and Ms. Charlotte Marsh have been certified as a Diplomate of the American Board of Toxicology.
The American Board of Toxicology (ABT) established the certification process to “evaluate and document competency in the field of toxicology.”
“ABT Diplomates participate in all aspects of the profession of toxicology including: the design and interpretation of safety studies for product development; review and interpretation of such studies for regulatory compliance; basic and applied research into toxic effects, mechanisms of toxic action, toxicokinetics and toxicodynamics; and education of undergraduates, professional and graduate students and the public in the science of toxicology through courses, legal cases and media interactions.”
Dr. Alex Gauthier is a toxicologist specializing in medical device biocompatibility, toxicological risk assessment, pharmaceutical nonclinical safety assessment, and large animal safety and efficacy studies.
Ms. Charlotte Marsh is a toxicologist specializing in product stewardship, human health risk assessment, and global chemical compliance.
Congratulations, Alex and Charlotte!
ECHA identifies four new hazard categories for endocrine-disrupting chemicals in its updated guidance on the classification, labelling, and packaging of substances and mixtures (CLP).
On November 13, the European Chemicals Agency (ECHA) published an updated version of its Guidance on the Application of the CLP Criteria to address the new hazard classes for endocrine disruption (ED) and PMT/vPvM[1] properties. The guidance identifies four new hazard categories for endocrine-disrupting chemicals, including “known or presumed” (Category 1) and “suspected” (Category 2) endocrine disruptors for human health or the environment. The guidance describes the criteria for classification, and advocates for the use of a weight-of-evidence approach informed by expert judgment and considering all available relevant information.
For the ED hazard classes, the criteria involve an evaluation of endocrine activity, adverse effects, and a biologically plausible link via mode-of-action analyses. Assessment of endocrine activity may involve mechanistic information from in vitro and in vivo studies, as well as results from in silico models. The guidance provides example ED classifications for human health and environmental hazards based on estrogen, androgen, thyroid, and steroidogenic (EATS) and non-EATS modalities.
For existing substances placed on the European Union (EU) market before May 1, 2025, classification and labeling for the new endpoints is mandatory starting November 2026. For mixtures placed on the EU market before May 1, 2026, classification and labeling for the new endpoints is mandatory starting May 1, 2028. The mandatory deadlines are earlier for new substances and mixtures placed on the market after May 1, 2025, and May 1, 2026, respectively.
For more than two decades, Gradient scientists have been at the forefront of the topic of endocrine-disrupting chemicals, including:
Timeline to Adopt New EU Hazard Classes
To discuss preparing for the requirements of this regulation, please feel free to contact Gradient.
Contact:
Ari S. Lewis, M.S.
Principal
Tim Verslycke, Ph.D.
Principal
Charlotte Marsh, M.S., CPPS
Senior Toxicologist
Gradient Senior Toxicologist Dr. Alex Gauthier will be presenting at the ACT 2024 Annual Meeting, November 17-20, 2024 in Austin, TX.
“Weight-of-Evidence Carcinogenicity Assessment of GLP-1RA Drugs.” A. Gauthier, M. Khazaee, I. Mohar
Gradient Principal Scientist Dr. Isaac Mohar will be presenting at the Pharma Ed Resources, Inc. Extractables & Leachables West 2024 Summit, November 13-14, 2024 in La Jolla, CA.
“Qualification of Extractables and Leachables for Combination Products.” I. Mohar, E. Hill (BA Sciences)
Join Trends authors in a webinar expanding on their articles in the Fall 2024 issue on energy and the environment. Topics include challenges in evaluating PM2.5 toxicity, environmental and community impacts of large data centers, and potential human health and environmental risks of carbon dioxide capture chemicals. You can read the full issue of Trends here.