N2: Navigating Occupational Exposure Modeling in TSCA Risk Evaluations

Kansas City Convention Center 

Room: 2505 A 

CM Credit Hours: 1 

The amended TSCA requires the EPA to evaluate and manage risk for existing chemicals in the U.S. EPA has published 16 draft or final risk evaluations using occupational exposure modeling in these risk evaluations. When monitoring data is insufficient or unavailable, exposure modeling is used in these assessments. The EPA has published two frameworks (inhalation and dermal) for evaluating chemical exposures in occupational exposure scenarios (OESs). For inhalation exposure modeling, the EPA employs mass-balance models. The dermal exposure modeling approach relies on a screening-level tool with five inputs. Regulatory actions are influenced by modeling results. Detailed instruction on EPA's frameworks for input selection and evaluation will be provided. A comparison of the EPA OES-based approach with AIHA's exposure assessment strategy will be discussed. A brief example of a solvent-specific modeling assessment that uses a mass-balance model will be reviewed for input sources, model selection, and evaluation of information. The results of the assessment for the OES will be presented, and the ultimate impact on the risk evaluation and risk management rule will be discussed.

Upon completion, the participant will be able to:

• Recognize the reasons that EPA uses exposure modeling in risk evaluations.
• Summarize the structure of TSCA risk evaluations.
• Explain the methods and types of input parameters used by EPA.
• List the EPA TSCA evaluation criteria for sources of formulations and data.
• Describe how EPA formulates a model for a specific OES.
• Apply EPA's modeling framework to a worked example for a solvent.
• Evaluate the limitations of TSCA modeling approaches.
• Provide examples of how input selection can impact assessments. 

Intermediate

Polling

Quiz

Corporation/Company

All Industries

Also part of the Virtual Program

Available as part of AIHA Connect OnDemand

Hazard Recognition/Exposure Assessment

Risk Assessment and Management

Standards, Regulations and Legal Issues