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PDC 10 - OELs: Tools for Assessing Worker Health​​ Risk

Enterprise Risk​ Management and Risk Assessment​ Track

Intermediate | Credits: 8 CM Credit Hours 

Sunday, October 29 | 8:00 AM – 5:00 PM | Limit 40


The sheer number of chemicals in commerce makes the development of a traditional occupational exposure limit (OEL) for every chemical an overwhelming goal. The fundamental core of the occupational risk assessment process is the comparison of an estimate of exposure potential with a chemical’s toxic potency, often called a “hazard quotient.” This course will highlight the array of different sources and types of chemical exposure guidance (OELs), their uses and limitations, and the linkage between them. The tools can be viewed as a hierarchy where some types of OELs can be developed with less data or resource investment, while others require more data but also provide greater certainty in the result and more robust information for making risk management decisions. A key skill for the IH is to know the difference between these methods and the basis for selecting each alternative for their risk assessment scenario. Skill development in these areas will be addressed in this course.

*Registration includes boxed lunch.


Participants should have a basic understanding of toxicology.

Learning Aids

Attendees must bring a scientific calculator to the course.

Value Added

Course provides users guides and hands-on training.​​

Course Outline

  • Introduction to Key Online OEL Resources
  • The Range of OEL Derivation Methods and Their Relationship to Each Other as Tools that Vary in Data Requirements and Level of Uncertainty
  • Introduction to the Suite of OEL Tools and Alternate Methods
  • Breakout Session to Develop OELs
  • Discuss and Report on Scenario Results

Learning Outcomes

Upon completion, participants will be able to:

  • Identify key online resources for finding and selecting an OEL.
  • Describe the range of OEL derivation methods and their relationship to each other as tools that vary in data requirements and level of uncertainty.
  • Derive an OEL from a data set using alternative methods.
  • Demonstrate application of a systematic approach to selecting an OEL method consistent with the needs or different occupational risk assessment scenarios.

Transfer of Knowledge

Instructors will evaluate participants’ understanding of the materials presented based on:

  • Practice exercises
  • Group activities


Name and Bio

Andrew Maier, PhD, CIH, DABT, Associate Professor, University of Cincinnati, Cincinnati, OH.

Dr. Andrew Maier is an Associate Professor at the University of Cincinnati and holds a Ph.D. in toxicology from the University of Cincinnati and an MS in Industrial Health from the University of Michigan. He is certified in both industrial hygiene (CIH) and toxicology (DABT). His research focuses on occupational risk assessment methods and tools, including developing and applying methods for setting exposure limits for acute and chronic occupational and community exposures. He is a past chair of the WEEL Committee and its current publications coordinator.​

Daniel E. Arrieta, PhD, DABT, Senior Toxicologist, Chevron Phillips Chemical Company LP, The Woodlands, TX.

Daniel E. Arrieta earned his PhD in pharmacology and toxicology from the University of California, Davis. He has worked at NIOSH as an Associate Service Fellow studying the effects of chemical allergens using a murine (mouse) model. At Chevron Phillips Chemical LP, he is a staff toxicologist. Mr. Arrieta manages and provides technical support to the Specialty Chemicals and Drilling Specialties business lines in matters related to chemical management programs (HPV, EHPV, OECD SIDS HPV) and global registrations (e.g. Australia, Canada, China, Europe, United States, and Offshore Drilling in The North Sea). He coordinates toxicity testing, and participates in various trade associations. Mr. Arrieta chairs the American Chemistry Council (ACC) Hydrocarbon Solvents Panel. He is a Diplomate of the American Board of Toxicology (DABT®), member of the Society of Toxicology and AIHA®, serves on the Workplace Environmental Exposure Level (WEEL) Committee, and co-authored a book chapter on hazard identification for beginners.​

Robert Nocco, CIH, CSP
Robert Nocco, CIH, CSP, Technical Team Manager, Chevron Corporation, San Ramon, CA.

Bob Nocco, CIH, CSP – Bob has over 35 years of diverse EHS experience in the petroleum industry. He has been involved in leading the OEL setting process with his current employer as well as serving as a member of the UCinn/TERA (formally AIHA) Workplace Environment Exposure Limit (WEEL) Committee.  He holds 2 M.S. degrees from University of Florida in Pharmacy (Clinical Toxicology) and Veterinary Medical Science (Forensic Toxicology) as well as 2 other M.S. degrees from Drexel University in Environmental Science and from CUNY-Hunter College in Environmental Health/Industrial Hygiene.​

Sophie Jia, MD, PhD, DABT, Senior Toxicoligist, Chevron Phillips Chemical Company LP, The Woodlands, TX.

Dr. Sophie Jia received her MD from Shandong Medical University in China and PhD in Toxicology from the University of Texas at Austin. She has two years of toxicology study director experience with a CRO and 11 years of industry toxicology experience with Chevron Phillips Chemical Company. Dr. Jia serves on Occupational Alliance for Risk Science (OARS)-Workplace Environment Exposure Level (WEEL) Committee. She is a member of her company’s OEL advisory committee. She is a diplomate of the American Board of Toxicology and a member of the Society of Toxicology and AIHA®. She serves on several industry association groups and chairs some of them. Dr. Jia has made several presentations to regional and national meetings including meetings hosted by the Society of Toxicology, Gordon Research Conference, and AIHA.​