Exposure Scenarios – Are you ready to comply?

June 2018 marked an important REACH deadline for companies that manufacture or import substances in quantities above 1 tonne per year. As the numbers of substances to be registered will increase significantly and many importers and manufacturers will face REACH for the first time, in this article Dr Michael Piber asks ‘Exposure Scenarios – Are you prepared for the obligations?’


REACH introduced a stepwise system for the registration of substances already on the European market. The most hazardous substances and those manufactured or imported in the largest quantities (>1000 tonnes) were to be registered first, in 2010, followed by the registration of chemicals in 2013 in the next largest quantities (100-1000 tonnes). Finally, substances that are manufactured or imported between 1-100 tonnes per year per company are to be registered last, since 2018. In 2018 REACH completed the gathering of data on existing substances on the European market, resulting in the most comprehensive chemicals database in the world.


The 2018 registration deadline was quite different from the two previous ones, in terms of both the number of registrations and the type of registrants. More than 70 000 registrations were prepared in 2018. This is three times more than previously prepared for either of the previous deadlines. Noteworthy, many of the registrants were expected to be inexperienced and located outside the chemical sector, and there will be more small and medium-sized enterprises (SMEs) than for the previous registration deadlines. The new substance information exchange forums (SIEFs) will also be small or even consist of only a single company, while at the same time, there will be less information available on the substances to be registered.


As part of the REACH registration process, for substances in quantities above 10 tonnes per year and registrant a chemical safety assessment (CSA) needs to be performed. The CSA includes the assessment of human and environmental hazards as well as a persistent, bioaccumulative and toxic (PBT) and very persistent and very bioaccumulative (vPvB) assessment. The CSA is carried out to demonstrate that the risks from the exposure to a substance, during its manufacture and use, are controlled when specific operational conditions and risk management measures are applied. The outcome of the CSA is documented in the chemical safety report (CSR), which is the key source from which the registrant provides information to all users of chemicals. The single elements to be included in the CSR are listed in Annex I, section 7 of REACH.


If the registrant concludes that the substance is hazardous or is assessed to be PBT or vPvB, the CSA shall also include the generation of one or more exposure scenarios (ES) for all uses of the substance the registrant intends to support. An ES is a set of information that describes the conditions under which the risk associated with the identified uses of a substance can be controlled.


The steps necessary to assess the exposure and associated risk of a substance are:

  • Gathering all possible uses of the substance based on information from downstream users. Every identified use is characterized by the “use descriptor system” which is based on five descriptors: sector of use (SU), product category (PC), process category (PROC), article code (AC) and environmental release category (ERC)
  • Describing the expected release and migration of the substance (based on its properties, the matrix, product design and conditions of use) as well as behavioral aspects of exposed users related to the substance.
  • Determining the quantitative exposure to the substance for the different uses. This assessment is performed by exposure tools like ECETOC TRA (European Centre For Ecotoxicology and Toxicology of Chemicals – Targeted Risk Assessment)
  • Performing a risk characterization by comparing
    • the expected exposure of human population to the substance with the appropriate derived no-effect level (DNEL). DNEL is the level of exposure to a substance, below which no adverse effects are expected to occur
    • the environmental concentration of the substance in each environmental sphere with the predicted no-effect concentration (PNEC). PNEC is the concentration of the substance below which adverse effects in the environmental sphere of concern are not expected to occur.


As a result for each ES, the risk characterization ratio (RCR) is calculated by dividing the expected exposure by the no-effect level/concentration. Where control of risk cannot be demonstrated (that means RCR>1), the registrant can iterate his assessment by suggesting more stringent operational conditions, developing more risk management measures or limiting the supported uses.


What needs to be done for substances that will be registered after 2018?


Downstream users (DU) receiving extended-SDSs should check the content of the ES describing their uses to ensure that their conditions of uses are covered and the risk management measures are implemented. In cases the DU’s uses are not covered they should communicate their use to the supplier.
Importer or manufacturers intending to register a substance as member of a joint submission should check that the current dossier covers all uses of their DUs by the described ES. If the uses are not covered, the registrant should either communicate the use with the SIEF, check if an exemption pursuant to Art. 37(4) of REACH applies, or create an own CSR.

Registrants of hazardous substances (in quantities above 10 tonnes) where no joint submission is available should start creating exposure scenarios for the intended uses of their substance as soon as possible to ensure a successful registration.


THE AUTHOR – Dr Michael Piber has over 10 years of experience in the regulation of chemicals at both National and European Level. Michael has worked as a regulatory expert in industry and is now managing director of Arcerion Consulting. Contact Michael at michael.piber@arcerion.com or on +49 (0)178 1982277.