Toxicology Consultants & Assessment Specialists, LLC

Professional Experience and Toxicological Specializations

TCAS has assessed hundreds of different types of toxic substances and exposure effects
TCAS has assessed hundreds of different types of toxic substances and exposure effects.[a]

TCAS provides professional, comprehensive forensic and environmental exposure analysis, risk assessments and causation determinations. With more than 34 years of hands-on experience, our cases cover a vast range of toxic exposure-related issues combining toxicological assessments, guidance, interpretation of laboratory results, opinions and expert consults.

TCAS is regularly retained for toxicological risk assessments, causation assessments, written reports, affidavits and expert testimony. We have assessed hundreds of different types of toxic substances and exposure effects on behalf of plaintiffs, defendants, attorneys, prosecutors, public defenders, State attorney generals and the U.S. Department of Justice. Dr. Sawyer performs the initial research and testing as well as exposure and dose calculations necessary to assess potential or alleged toxic exposures under a variety of conditions and circumstances. These include residential exposures, industrial contamination, criminal homicide and alcohol intoxications, accidental poisonings, general and specific chemical causation, medical malpractice involving pharmaceuticals and others.

Areas of Expertise

Click on any area to view additional information

Forensic Toxicology


Environmental Testing


Toxic Exposures


Risk Assessment


Causation Evaluation


Areas of Specialization

The following summaries are merely partial lists. Click on any area to view information on that topic. Areas highlighted in green represent toxicological subjects supported by TCAS-published case studies and/or toxic exposure reference pages. We invite you to contact our office for answers to questions regarding any toxic substance not listed here.


  1. TCAS report demonstrative (redacted), © Copyright 2017 TCAS
  2. Public domain thumbnail images courtesy, images are property of their respective owners

A Message from Dr. William R. Sawyer
Chief Toxicologist, TCAS, LLC

A message from Dr. William R. Sawyer, Expert Toxicologist

"TCAS is committed to providing our clients with the full benefit of our toxicological expertise. The areas listed here represent only a small part of our experience and capabilities. Please call our office for answers to questions and concerns."

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Pharmaceutical Toxicology  |  Consumer Products  |  Human Health Risk Assessments

This is an informational and instructional website devoted to toxicology. It presents both original and edited public-domain content compiled as a useful educational resource. References and footnotes have been included wherever possible and image sources have been cited where appropriate. Although most pages can be printed or downloaded as PDF files (and we encourage you to make constructive use of our information), this website is copyrighted and material may only be reproduced and/or distributed with prior permission from TCAS, LLC.