REACH: Developing Exposure Scenarios for the Chemical Safety Assessment
The December 2010 registration deadline looms for chemicals produced or imported in quantities of greater than 1000 tonnes per year as well as substances classified as carcinogenic, mutagenic or reprotoxic or as dangerous for the aquatic environment. One of the aims of the registration process is to demonstrate that exposures to hazardous substances are less than a benchmark level – the Derived No Effects Level (DNEL) – at which no adverse effects would be expected. In REACH speak, the Risk Characterisation Ratio must be less than unity.
The IOM is currently supporting a number of clients in their preparations for registration. We have been actively involved in developing exposure scenarios, undertaking exposure assessments, calculating risk characterisation ratios and drafting the resulting sections of Chemical Safety Reports. We are also an active member of the European consortium which has been developing Advanced REACH Tool (ART) for exposure modelling (http://www.advancedreachtool.com/) which will be released towards the end of February
Our experience to date, suggests a dearth of exposure data for many exposure scenarios and inadequate information on which to base reliable and accurate exposure estimates. In the absence of measurement data, models for the prediction of exposure are designed to ensure that exposures are not underestimated which could lead to an inflated Risk Characterisation Ratio. This may even result in risk characterisation ratios being greater than one, prompting the need for improved and potentially costly risk management measures (RMM). The only certain way of determining workplace exposures is to actually measure them as part of a properly designed survey. The combination of good measurement data with the use of a modelling tool such as ART enables a realistic exposure assessment to be made leading to a proper assessment of the risk characterisation ratio.
The IOM can help you with the development and documentation of exposure scenarios, the determination of exposure levels using modelling and/or measurement surveys, advise on risk management measures and assist in the drafting of the Chemical Safety Report and extended safety data sheets. The collection of good measurement data now will enable a realistic appraisal of risk in the Chemical Safety Report and the recommendation of appropriate RMM.