Inter-assessor Agreement for TREXMO and Its Models Outside the Translation Framework

Area of Science:

• Occupational Health and Safety
• Risk Assessment
• Chemical Safety

Background:

• Occupational exposure models are crucial for workplace risk assessment under REACH (Registration, Evaluation, Authorization, and restriction of CHemicals).
• Inconsistent results among assessors using these models raise concerns about the reliability of risk conclusions.
• Inter-assessor agreement is vital for standardized and dependable chemical safety evaluations.

Purpose of the Study:

• To evaluate the impact of the TREXMO (v1, 2016) web tool on inter-assessor agreement for occupational exposure modeling.
• To determine if TREXMO improves consistency in parameter selection and exposure estimation compared to manual methods.
• To assess the effectiveness of TREXMO in facilitating parameter translations between different exposure models.

Main Methods:

• Eighteen assessors conducted exposure assessments for six distinct workplace scenarios.
• Assessments were performed both with and without the TREXMO translation tool.
• Inter-assessor agreement was quantified and compared between the two approaches, focusing on parameter selection and model translations.

Main Results:

• In over half of the cases, TREXMO usage led to better agreement among assessors compared to manual parameter coding.
• Parameters related to activity (e.g., handling types) and exposure control (e.g., local controls) showed the most improvement.
• Translating between models using TREXMO significantly reduced the relative standard deviation of exposure estimates (e.g., from 70-121% to 29-94% for Stoffenmanager vapors).

Conclusions:

• The TREXMO tool demonstrates potential to significantly enhance inter-assessor agreement in occupational exposure modeling under REACH.
• Improved consistency was observed in parameter selection and exposure estimation, particularly when using TREXMO for model translations.
• Further research with more assessors and exposure situations is recommended to fully establish TREXMO's impact.