Aggregate Consumer Exposure and Risk Assessment in the EU—A Case Study

Consumer exposure to chemicals in the EU is currently assessed separately for different products without aggregating exposure from different sources. A more integrated ap proach represents a promising opportunity to improve comprehensive risk evaluation and transparency across the value chain. This study develops aggregate consumer expo sure and risk assessment methods that involve calculation of exposure and risk for each pathway using the risk characterization ratio (RCR) as a uniform risk metric. Aggregate risk is obtained by adding up pathway-specific RCRs. The developed methodology re presents a new approach by evaluating exposure of seven population groups via all path ways and by using key input values normalized to body weight to reflect population-specific differences. The study demonstrates the practical applicability of the methodol o gy by assessing consumer exposure to the antioxidant ethylene bis[3,3-bis(3-tert-butyl-4-hydroxyphenyl)butyrate] (Hostanox^® O 3), resulting from its use in food and drinking water contact materials, textiles and sealants. This case study demonstrates aggregate RCRs well below one for all groups. The highest aggregate RCRs are found for infants and toddlers, reflecting their proportionally higher food consumption and skin surface area. The methodology is transparent and can easily be applied to other substances, e.g., by industry stakeholders and authorities, if the substance concentration in products can be established. This study may inform further development of aggregate exposure and risk methods in EU regulatory frameworks.