• Toxicology
  • Human Health Risk Assessment
  • Ecological Risk Assessment
  • Multimedia and Multi-Disciplinary Assessments
  • Litigation Support
  • Chemical Safety Reports

  • Full Profile

    Dr. Frez is a Board-Certified Toxicologist with over 25 years of experience in the specialty chemical and consulting industries. His expertise includes chemical residue analysis for regional fate and transport models, providing toxicology testing management, and risk assessment support for new and existing products and raw materials, as well as consulting with business sectors at all stages of development and use to provide insight on chemical toxicity and alternative design options. Bill’s interest and expertise in reaching health protective solutions to meet business objectives while maintaining regulatory requirements is exemplified in the very personal ownership taken on project work. In addition to key technical activities, he has been active in defense of existing and emerging chemistries in various advocacy, consortia, and industry trade groups. In addition to these critical technical activities, Bill supports enterprise Product Stewardship as a certified internal auditor for facility certification under the ISO 14001 Risk Management System Product Safety Code.


    • Ph.D., Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, 1988
    • M.S., Biology, University of Michigan, Ann Arbor, MI, 1983
    • B.S., Biology, Wayne State University, Detroit MI, 1975

    Professional Affiliations

    • Diplomate of the American Board of Toxicology
    • Society of Toxicology

    Certifications and Training

    • Diplomate of the American Board of Toxicology (DABT)
    • ISO 14001 Certified Internal Auditor Product Safety Code (2017)

    Key Experience

    Industry Experience

    GE Plastics, Mt. Vernon, IN

    RCRA Corrective Action Risk Assessment

    A risk assessment was developed to evaluate exposures associated with waste materials regulated under the Resource Conservation and Recovery Act (RCRA) Corrective Action. The risk assessment focused on development of performance standards, evaluation of Solid Waste Management Units (SWMU) consolidation, and assessment of potential off-site migration to a local river.

    Confidential Client

    Formaldehyde Release Assessment

    Presentation to the European Chemicals Agency (ECHA) Risk Assessment Committee (RAC) of Risk Associated with Formaldehyde Releasers Used in Metal Working and Well Drilling Fluids – Helsinki, Finland. Metal working and well drilling fluids use formaldehyde-releasing substances to prevent biofouling and mitigate hydrogen sulfide release. The concentration of the formaldehyde released in such applications is well below the theoretical maximum amount designed into the molecule. A presentation was made to the ECHA RAC to emphasize the conditions of and practicality associated with real-world formaldehyde release.

    Confidential Client

    Drilling Fluid Additive Assessment

    Assessment of Skin Sensitization Potential of a Drilling Fluid Additive. Sensitization was assessed for a hydrogen sulfide scavenger additive used in well drilling fluids. Using a local lymph node assay (LLNA) the skin sensitivity suggested the results constituted a false positive based on historical data from similar chemistries. Subsequent testing using guinea pig Buehler methods did not confirm the substance to be a sensitizer. However, since European Union (EU)-specific rules required that the substance be categorized as a sensitizer according to the LLNA results, the safety data sheet (SDS) was modified, and written customer-facing communications were developed to maintain substance sales.

    U.S. Department of the Navy, Honolulu, HI

    Blood Lead Uptake Bioaccessability Evaluation

    Substantial lead contamination was detected at a former small arm firing range located near Barber’s Point on the island of Honolulu. Most of the lead was in “pellet” form suggesting that it was unlikely to be bioaccessable by human receptors. Blood lead levels were estimated for potential receptors under the assumptions of complete and limited bioaccessability. Data were used in risk management decisions resulting in remediation of the site.

    United States Air Force, Altus Air Force, Altus, OK

    Indoor Air Intrusion Risk Assessment

    As part of the base RCRA Corrective Action program, the risk associated with the potential exposure to chemical vapors in air was evaluated using current vapor intrusion models (i.e., Johnson and Ettinger). Using a “worst-case” approach, air samples were taken to verify the results of modeling. The air sampling showed that vapor intrusion into indoor air at the base resulted in negligible risk. These results confirmed that additional modeling was not required and concluded that no further action was required with respect to the indoor air exposure pathway.

    Confidential Client, Honolulu, HI

    Physiologically Based Pharmacokinetic Modeling of Lead Uptake

    Current regulatory models for the absorption, distribution, metabolism, and elimination of lead are insufficient to address short term (i.e., less than 90-day) lead exposures. Physiologically Based Pharmacokinetic (PBPK) modeling was used to show that short-term worker exposure to lead in soil at levels exceeding the default industrial criterion would not elevate blood lead levels above permissible concentrations.

    Arizona Department of Environmental Quality, Phoenix, AZ

    Litigation Support

    An expedited risk assessment was developed to support legal counsel regarding the potential for imminent and substantial risk to receptors via the groundwater pathway. The approach utilized a streamlined comparison of data to risk-based benchmarks published by the United States Environmental Protection Agency (USEPA), generating a report within less than one week to be provided during the discovery process. The case was settled out of court.

    U.S. Department of the Navy, Atsugi Naval Air Station, Atsugi, Japan

    Screening Level Multipathway Exposure Analysis Plan and Risk Assessment

    This plan was developed to identify exposure routes relevant to potential emission of dioxins and polychlorinated biphenyls (PCBs) from a hazardous waste incinerator located adjacent to the Naval Air Station in Atsugi, Japan. The plan identified food chain pathways and direct inhalation pathways as critical for subsequent negotiations between the Department of the Navy and Japan.

    Confidential Client

    Toxic Substances Control Act (TSCA) Premanufacturing Notice (PMN) Inhalation Toxicity Study Design, Monitoring and Risk Assessment for Cationic Surfactant

    USEPA recommended a lengthy and costly tiered series of toxicity tests to establish safe use requirements for a spray coating surfactant additive. A streamlined inhalation toxicity study design was developed, proposed, and accepted by the agency that saved time and money and allowed the business to expedite product development and sales.

    Confidential Client

    Expert Statement-Physiologically Based Pharmacokinetic Assessment of Borated Petroleum Additive

    A PBPK model was employed to estimate additive resident times, blood levels, accumulation, and other key pharmacokinetic parameters in Sprague Dawley rats over the course over a 90-day exposure period. The model results showed negligible accumulation and rapid elimination. The results were documented in an expert statement presented to Chinese regulators that was used to gain regulatory notification and support export of the substance into the Asia Pacific market.

    U.S. Department of the Navy, Guam

    Risk Communication and Community Relations

    A human health risk assessment indicated that residential receptors in Guam may be at increased risk from the ingestion of contaminated fish taken from the Agana Swamp/River system. The client proactively sought community involvement to direct further risk assessment, investigational, and remedial activities. Risk communication activities were conducted and involved medical consultation, data interpretation with respect to health risks, and a presentation of the risk assessment process.

    Bruce Nuclear Power Development, Tiverton, Ontario

    Low Level Radioactive Waste Spill Risk Assessment

    A spill risk assessment was performed using a combination of fault tree analyses and chemical risk assessment techniques to determine the likelihood that radioactively contaminated waste might be associated with adverse health risks. The assessment concluded that, given the current engineering practices in place at the plant, the risk to potential human receptors was negligible.

    U.S. Department of the Navy, Atsugi, Japan

    Litigation Support, Shinkampo Incinerator

    A hazardous waste incinerator has operated upwind of the U.S. Naval Air Station in Atsugi, Japan for several years. Emissions data have been collected indicating elevated levels of dioxins and dioxin-like chemicals. The U.S. Navy requested support to determine the potential for adverse health effects to Navy personnel and local residents related to emissions from the incinerator. The project supported negotiations between the Department of the Navy and Japan, which resulted in mitigation of excess emissions.

    Publications and Presentations

    Eadie, B.J., C.P. Rice, and W.A. Frez. 1982. The role of the benthic boundary layer in the cycling of PCBs in the Great Lakes. In:  Physical Behavior of PCBs in the Great Lakes. D. Mackay, S. Patterson, S.J. Eisenreich, and M.S. Simmons (eds.) Ann Arbor Science Publishers, Ann Arbor, MI.

    Frez, W. 2009. Vapor Intrusion: Concepts and Case Studies. Vapor Intrusion – Regulations, Monitoring, Management, and Mitigation Seminar. Sponsored by Land Science Technologies, Columbus, OH.

    Frez, W. 2005. Genetically Modified Organisms. Encyclopedia of Toxicology. Elsevier Publishing Co. New York, NY.

    Frez, W., N. Basta, J. Bryan, V. Ewald, L. Maclean, S. Medearis, S. Walter, and C. Zenigami. 2005. Making. Presented at the Annual International Conference on Soils, Sediments and Water. Amherst, MA October 19, 2005.

    Frez, W., N. Basta, J. Bryan, V. Ewald, L. Maclean, S. Medearis, S. Walter, and C. Zenigami. 2004. Arsenic Bioavailability Considerations in Risk Management Decision-Making. Accepted for Presentation: Midwestern States Risk Assessment Symposium, August 25-27. 2004.

    Frez, W.A. and S.A. Walter. 2002. Pre-Emptive Uncertainty Assessment. The Military Engineer. 94 (615): 33-36.

    Frez, W.A., J.N. Tolbert, B. Hartman, and T.R. Kline. 1998. Determining risk-based remediation requirements using rapid flux chamber technology. Proceedings of the First International Symposium on Remediation of Chlorinated Compounds. Battelle Press, Columbus, OH.

    Frez, W.A. 1991. Procedure for Regulating Bioconcentratable Materials: Anticipated Costs to the Regulated Community. Presented at Fall 1991 Meeting of the Central Great Lakes Regional Chapter of SETAC, September 27, 1991, St. Clair, MI.

    Frez, W.A. 1988. The toxicokinetics of hydrophobic contaminants in the invertebrate Mysis relicta. Ph.D. Thesis, School of Public Health, University of Michigan. Ann Arbor, MI.

    Frez, W.A., and P.F. Landrum. 1987. Role of Lipids in the Toxicokinetics of PCB and PAH in P. hoyi and M. relicta. Presented at the 1987 Annual Meeting of the International Association of Great Lakes Research. Ann Arbor, MI.

    Frez, W.A., P.F. Landrum, T.D. Fontaine III, and M.S. Simmons. 1987. A Kinetics Based Model to Predict the Accumulation of PAH and PCB from Food and Water in Mysis relicta. Presented at the 1987 Annual Meeting of the International Association of Great Lakes Research, Ann Arbor, MI.

    Frez, W.A., P.F. Landrum, T.D. Fontaine III, and M.S. Simmons. 1987. Sensitivity and Uncertainty Analyses of a Kinetics-Based Model of Xenobiotic Accumulation of Mysis relicta. Presented at the 1987 Eighth Annual Meeting of the Society of Environmental Toxicology and Chemistry, Pensacola, Florida.

    Frez, W.A. and P.F. Landrum. 1986. Species dependent uptake of PAH in Great Lakes invertebrates. In:  Polynuclear Aromatic Hydrocarbons: Chemistry, Characterization, and Carcinogenesis. M.J. Cooke and A.J. Dennis (eds). Battelle Press, Columbus, OH.

    Frez, W.A., P.F. Landrum, and M.S. Simmons. 1985. The influence of food type on the toxicokinetics of aquatic animals. Presented at the Sixth Annual Meeting of the Society of Environmental Toxicology and Chemistry, Nov. 10-13, 1985, St. Louis, MO.

    Frez, W.A. and P.F. Landrum. 1984. Species dependent uptake of PAH Great Lakes invertebrates. Presented at the Ninth International Symposium on Polynuclear Aromatic Hydrocarbons. October 30 – November 1, 1984. Columbus, OH.

    Gardner, W.S., W.A. Frez, E.A. Cichocki, and C.C. Parrish. 1985. Micromethod for lipids in aquatic invertebrates. Limnology and Oceanography 30(5): 1099-1105.

    Gardner, W.S., T.F. Nalepa, W.A. Frez, E.A. Cichocki, and P.F. Landrum. 1985. Seasonal Patterns in lipid content of Lake Michigan macroinvertebrates. Can. J. Fish. Aquat. Sci. 42:  1827-1832.

    Lonie, C., W. Frez, J. Briggs, G. Barrett, J. Zhong, G. Delson, and L. Miller. 1999. Human health and ecological risk assessment for residential areas and wetlands potentially impacted by PCBs. Abstract Submitted, October 1999. PERC 2000 Symposium.

    Rice, C.P. and W.A. Frez. 1981. Application of Capillary Chromatography to the Study of Cycling of PCBs on Suspended Particles. Report to the Department of Commerce, NOAA, Great Lakes Environmental Research Laboratory. University of Michigan, Great Lakes Research Division.

    Rice, C.P., W.A. Frez, and B.J. Eadie. 1980. Levels of particulate associated PCBs in southern Lake Michigan: depth and seasonal effects. Presented by W.A. Frez at the Third Midwest Water Chemistry Workshop. Dec. 4-5, University of Michigan, Ann Arbor, MI.

    Smith, V.E., S.G. Rood, W.A. Frez, J.E. Fisher, D.J. Brokaw and M.D. Mullin. 1988. Comparison of PCB Patterns in Diving Ducks and Forage Site Sediments of the Lower Detroit River, Michigan. Presented by W.A. Frez at the May 1988 Meeting of the International Association of Great Lakes Research, Hamilton, ONT.

    Yagi, Y., T.S. McClellan, W.A. Frez, and D.B. Clewell. 1978. Characterization of a small plasmid determining resistance to erythromycin, lincomycin and vernamycin B in a strain of Streptococcus sanguis isolated from dental plaque. Antimicrobial Agents and Chemotherapy. May 1978.

    Yagi, Y., T.S. McClellan, W.A. Frez, and D.B. Clewell. 1977. Isolation of an erythromycin resistance plasmid from a strain of Streptococcus sanguis. Presented by Y. Yagi at the International Association for Dental Research Convention, 1977, Washington, D.C.