Review of Tier 1 workplace exposure estimates for petroleum substances in REACH dossiers

For the exposure assessment in the 2010 REACH dossiers of petroleum substances, Concawe has used the Tier 1 exposure model ECETOC TRA v.2. To account for the heavier, less volatile and more complex petroleum substances and the corresponding exposure situations, several modifications not originally within the scope of the ECETOC TRA were developed, including an approach to estimate liquid aerosol along with some risk management measures describing the use and handling of petroleum substances commonly in use in the European oil refining industry. In this project, Chemical Safety Assessments (CSA) on these petroleum substances were evaluated concerning relevant industry areas and included scenarios. The comparison exercise showed some discrepancies depending on substance group and the specific scenarios, which could be partly attributed to new modifiers or other changes of the ECETOC standard algorithm. Concerning aerosol exposure, no significant underestimations were found for the evaluated scenario in case of other lubricant base oils while in the case of heavy fuel oils (HFO), results were inconclusive. Overall, it is recognized that available sampling methods for liquid aerosol often tend to give biased or at least variable exposure results and this has to be considered for future investigations concerning risk assessment of petroleum substances or validation of the existing CSA. Measurements made for HFO showed higher overall and vapor concentrations compared to the aerosol values, suggesting that either vapor may be more relevant than previously assumed for high boiling petroleum substances or the corresponding aerosol measurements may not be suitable for a comparison with Derived No Effect Levels or model estimates. A qualitative evaluation of the updates made when changing from ECETOC TRA v.2 to v.3 suggested that inhalation exposure estimates will probably be lower if the more recent version is used due to newly introduced or changed measures or operational conditions and partly due to modified initial exposure estimates.