Generic Exposure Scenarios
Registration of substances under REACH that are classified and sold at greater than 10 tonnes requires that an exposure assessment is carried out for human health and the environment. This assessment is required to cover all the identified uses of the substance throughout the supply chain with any measures identified for the demonstration of safe use communicated via Exposure Scenarios in an Annex to the Safety Data Sheet (SDS).
Early in the REACH process, ESIG started to reach out to its downstream users (DU) by addressing them directly about their uses and collecting the answers. However, the responses received were frequently different in wording, not always conclusive and, in the end, often referred to similar uses. As a next step, the collected uses from over 15 different DU groups were brought together (under the umbrella of ESVOC) into Generic Exposure Scenarios (GES) allowing, for example, a registrant or formulator to identify and describe, for instance, a “coating scenario” regardless of any sectoral jargon.
GES were developed in close liaison with the main DU sector groups to ensure that safe use conditions applied when needed to demonstrate safe use reflects reality and are described in a manner relevant to the DUs and communicated in a consistent form by suppliers and their intermediaries e.g., formulators.
This GES approach was adopted by Cefic as the preferred approach for the implementation of Chemical Safety Assessments for commodity chemicals including the development of supporting guidance and excel templates for use in its implementation. It was extensively shared with stakeholders via ESIG/ESVOC workshops during the development, interested parties at many of the Cefic REACH Implementation Workshops (RIW) and the European Network on Exposure Scenario (ENES) meetings.
The adoption of the approach has enabled large numbers of substances (both solvents and non-solvents) to be registered and evaluated in an efficient and concise fashion, with no substantive issues having been raised by DU sectors. Where a sector flagged a slightly different or additional use – for example following the revision to the R12 Use Descriptors – then the necessary adaptions to the GESs were made.
Challenges & developments
As REACH developed, it became clear that the GES approach was not being applied consistently by all registrants. This can have several reasons, such as Chemical Safety Assessments (CSA) /dossiers being developed without proper regard for available Use Maps for supply chain communication. On the one hand, downstream user companies might not have responded to manufacturers’ requests for use information or, on the other hand, unrealistic Risk Management Measures (RMM) or conditions of use were communicated.
Poor consistency and lack of harmonized approaches pose a real problem for the formulators and their downstream users. Formulators, in preparing SDSs for their mixtures, are required to assure that their use is covered in the annex of the SDS and take the safe use measures into account for further communication to their customers. Formulators have found this challenging, as the Exposure Scenarios they receive from different suppliers are not always in a consistent format, and some of it can contain safe use advice that is not realistic for the actual conditions of use. Currently formulators are managing their compliance with REACH by forwarding the substance ES for each hazardous component in a mixture attached to the mixture SDS rather than adjusting the ES. This is not at all helpful for the end users, who are left to interpret what is ‘safe use’.
In a response to this, the Sector Use Map concept has been developed under ENES. It includes templates for sector specific communication about the conditions under which typical end-uses take place, including Specific Workers Exposure Descriptions (SWEDs), Specific Environmental Release Categories, SCEDs (Specific Consumer Exposure Descriptions (SCEDs). Standard Conditions of Use and Risk Management Measures from these use maps in CHESAR format can be used by registrants in the ECHA CHESAR (Chemical Safety Assessment) tool for the risk assessment in their registration dossiers.
In addition, formulators seek to communicate the safe conditions of use to their downstream users in a consistent way, which can be achieved with a so-called SUMI (Safe Use of Mixture Information sheet) attached to the mixtures SDS for end users. The input of the SUMI is provided by the substance risk assessment based on sector use maps. In the use map approach, the safe use concentration is the only flexible parameter, to assure that for all components in the mixture, the same Operational Conditions and Risk Management Measures apply for each contributing Scenario. For example, it would be very complex if for a specific activity (=contributing scenario) with a mixture, one ingredient requires Local Exhaust Ventilation, the other enhanced general ventilation and a third ingredient a limitation of use duration for < 1 hour.
In 2018/2019 ESIG revised the GES templates in such a way that they can be imported into Chesar as per the Sector Use Maps so that same IT formats are used.
The need to map the GES with the DU sector use maps was one of the outcomes of the use map pilot under ENES. For this, it is essential to also create SWED codes for the ESIG GES. We then started to look at content and ESIG exposure experts have worked throughout the last two years to improve the Generic Exposure Scenarios (GES) and develop SWED codes to be used in the various GES. The goal is to create ESIG’s own SWED (codes) and map the available downstream user sector use maps to ESIG’s own use maps. This will facilitate the tasks and decisions for risk assessors. The outcome of those risk assessments will better facilitate formulators who are required to create safe use information for their mixtures. Registrants will be able to use these GES SWEDs for their registration and as part of their eSDS.
In 2022 next to the mapping and creation of SWED codes, all SpERC factsheets and background documents will have concluded a full review that has started in 2019. The ESIG experts will also commence to review the need of updating the EGRET tool following new information with respect to the consumer exposure.