The ECETOC TF Report and landscaping document, and subsequent workshop has provided a platform to begin the process of developing clear guidance on aggregate consumer exposure assessment. Unless robust frameworks and guidance are established, variability in quality of exposure assessments will be observed. Achieving a systematic programme/framework for exposure assessment to ensure “exposure quality” will require broad stakeholder involvement and agreement across EU and International institutions. There was agreement to broaden cooperation with delegates from OECD, JRC, EPA, and ECHA offering to discuss future cooperation on this activity. The following observations and recommendations were concluded from the workshop:
Data Sharing: In parts of the industry (e.g. the fragrance industry) there is good experience with collection of anonymised data on product composition for inclusion in exposure estimates, which has saved the Industry several millions of Euros, and prevented unnecessary toxicology testing. Initiatives are needed to encourage other areas of industry to collaborate in this way and make available anonymised databases for exposure assessment, while protecting intellectual property.
Optimise existing tools: Approaches should be developed (including the use of case studies) to demonstrate how existing knowledge and tools can be (more) effectively applied in aggregate consumer exposure assessments. Guidance should be developed specifically to determine what represents the most suitable available models and the most suitable data sources for specific questions. The approaches should aim to improve the robustness of estimates using tiered and targeted strategies for data acquisition and application.
Transparency: Tools, data, documentation and software should be open access.
Read Across for exposure assessment could be useful as a means of ‘gap filling’ in data sparse situations, but criteria need to be developed to ensure confidence in such read across approaches. Data quality (amongst other criteria) would need to be assessed in order to determine the extent to which it might be applied to other settings (Tielemans et al, 2002). Consensus-based definitions for exposure-based read across would be required. This could be combined with an agreed process to extrapolate the applicability of data in different contexts (Hristozov et al, 2014). For example best practice exists in the occupational setting (Money and Margary, 2002; ECHA, 2012): could it be extended or adapted to consumer exposure? An internationally recognised rating system would help evaluate the quality of data.
Incorporate Life Cycle Analysis? How could life cycle perspectives/analysis be applied to help determine the nature of exposures?
Build databases on consumer information: public portals could facilitate discussion and data-sharing. Databases of relevant consumer use information, product composition and presence probability across domains are needed. Templates and mechanisms for the effective and transparent sharing of data, based on specific types of use (e.g. SCEDS and sub-PCs). Learnings from recent sector specific initiatives to describe representative concentration and presence probability data for substances and products (fragrances, cosmetics and food) should be evaluated. Mechanisms to enable the ‘non confidential’ information from market surveys to be made more widely available, such as habits and practices data: this is invariably non-product-specific information and would be extremely relevant to exposure assessment. Specific mention was made of the need for concentration data and presence probability data (product composition data).
Develop Harmonised Guidance (with validation/quality weighting criteria) for Fitness of Purpose within the Applicability Domain: Develop decision trees and problem formulation templates to assist robust consumer exposure and risk assessment. Well-stated and validated applicability domains with standardised descriptors recognising the unique factors of each model that determines its fitness for purpose (i.e. “pedigree”) are needed. Models should be validated, and validation across models should be conducted. Case studies could be used to exemplify this guidance. However, validation of guidance is difficult, thus a pragmatic way forward may be to build confidence in the methods by showing that the assumptions are plausible; the methods used are based on state of science approaches; and the results of the different methods of exposure assessment are compatible. The OECD provides a platform that could be used to harmonise these data/models/standards across geographies.
Establish Triggering Criteria for higher tier aggregate exposure assessment (e.g. source contribution, MAR approach, conservatism in initial assessment)
Obtaining data on product compositions: this is essential for exposure assessment, particularly aggregate exposure. Without reliable composition data, exposure assessments are based on worst case assumptions giving rise to product restrictions. Questions that need to be answered include: How do we collect, store, share and maintain anonymised product composition data? How do you overcome the barriers to implementing this action across geographies and industry sector groups? Who should lead such an activity? We should look to the example of the fragrance Industry who have achieved this while maintaining the industry’s intellectual property.
Data sharing across domains: Tools and data for aggregate exposure specific to domains and product categories exist, but there is little cross-talk across the domains. A Cefic LRI project could consider chemical assessments for chemicals ubiquitous across product types that cover different categories: run case studies on these chemicals to identify what tools are available for aggregate exposure assessment, and then assess the level of exposure across these categories.
Developing an agreed process to extrapolate the applicability of exposure data in different contexts. This does not yet exist in exposure assessment, but in hazard assessments processes have been developed to enable data from various sources to be combined. This could be a starting point for a similar approach in exposure assessment.
Developing a framework for exposure assessment of exposure data-poor chemicals. Criteria are being developed for quality and weight of evidence for hazard assessment (including read across), but not for exposure assessment. Questions that need answers include: Can the principles that are being developed for hazard assessment be applied for exposure assessment? How do you overcome the barriers to implementing this action across geographies and industry sector groups? Who should lead such an activity?