Robert Scofield, D.Env, MPH

Dr. Scofield is a Principal Toxicologist with RETRA and has more than 40 years of experience directing and conducting environmental health risk assessment, remediation, and due diligence projects across the United States and internationally. His expertise also includes product safety evaluation, risk assessment instruction, risk communication, and serving as a neutral third-party reviewer for both government and private entities.

He has supported Proposition 65 matters since the law’s inception in 1986, completing several hundred risk assessments involving consumer products, foods, occupational exposures, and ambient environmental conditions. His work has included derivation and evaluation of No Significant Risk Levels (NSRLs) and Maximum Allowable Dose Levels (MADLs), exposure assessment, test protocol design, and expert support in litigation, mediation, and informal negotiations. He is frequently invited to speak on Proposition 65 and has helped clients demonstrate that chemicals present in products are naturally occurring.

Dr. Scofield has managed or performed over 500 human health risk assessments for chemical contaminants in soil, water, and air. These projects have included Superfund and RCRA sites, Brownfield redevelopments, petroleum releases, manufactured gas plants, agricultural chemical sites, and other waste disposal or spill scenarios. He has also conducted or reviewed multi-pathway risk assessments involving diesel exhaust, waste incineration, and industrial stack emissions under a range of federal, state, and international regulatory frameworks. His evaluations have addressed health risks from a broad spectrum of substances, including petroleum hydrocarbons, PCBs, chlorinated solvents, PFAS, heavy metals, and pesticides.

His international work includes peer-reviewed and authored risk assessments across Europe, Asia, South America, and Australia—where he completed more than 20 assessments for contaminated land and air toxics sites and was approved as a risk assessor under New South Wales' Site Auditor Program. He has extensive experience critically evaluating toxicological and epidemiological literature to establish exposure limits, characterize dose-response relationships, and assess causality between chemical exposures and adverse health outcomes. His service includes peer review roles for the U.S. Department of Defense, the State of California, and a court-appointed neutral expert role in litigation involving manufactured gas plant residues in San Francisco Bay.

In product safety, Dr. Scofield has completed several hundred exposure assessments for consumer goods and foods. He has taught risk assessment and toxicology for academic institutions, private industry, and the California Bar Association. He was an active contributor to the development of the ASTM Risk-Based Corrective Action (RBCA) Standard for petroleum sites and has delivered training to state regulators as part of API and USEPA RBCA implementation efforts. He has also taught toxicology and risk assessment to Department of Defense project managers.

Dr. Scofield has been a member of the National Research Council’s Natural Attenuation Committee, an invited speaker at multiple Brownfields Asia Conferences, and a guest lecturer at the Chinese Research Academy of Environmental Sciences. He participated in a special session of the Royal Society of Chemists’ Toxicology Section on defining significant health risk, and served as a peer reviewer for the UK Department for Environment, Food, and Rural Affairs’ Category 4 Screening Levels for contaminated land.

In addition to his technical contributions, Dr. Scofield has frequently supported public communications at hearings and community meetings on behalf of clients navigating contentious environmental health issues.

Principal Toxicologist