Effect thresholds and ‘Adequate Control’ of risks

Abstract

Preparation of the new European REACH (Registration, Evaluation and Authorisation of CHemicals) regulation on chemicals has reached a critical stage. Depending on how key elements of the legislative proposal are finalised, especially that on authorisation of uses of 'substances of very high concern', REACH could either provide an effective measure to drive innovation towards cleaner and safer alternatives, or instead lead to further avoidable chemical exposures on the basis of demonstrated 'adequate control' of risks. Given that some key indicators of human and wildlife reproductive health continue to decline in parts of Europe, while evidence for chemical exposure as a contributory factor grows, it will clearly be vital to get the legislation right. GOAL AND SCOPE: Whereas there is now a consensus between the European Parliament and Council of the European Union that uses of persistent, bioaccumulative and toxic (PBT) and very persistent and very bioaccumulative (vPvB) substances should only be permitted when no safer alternatives are available, major differences remain regarding the manner in which other 'substances of very high concern' (including substances which are carcinogenic, mutagenic or toxic to reproduction (CMRs) and endocrine disruptors) are addressed. This paper examines those differences in more detail and proposes some ways forward. Using case studies of specific chemicals as examples, the paper critically evaluates the concepts of 'effect thresholds' and 'adequate control' of risks, which underpin the Council's proposal for many CMRs and endocrine disruptors. The subjectivity and uncertainties inherent in the threshold approach proposed by the Council, as illustrated by these case examples, bring its ability to ensure a high level of protection for the environment and human health into question: i. the nature and extent of toxic effects recorded depend on many different factors, including the type of test and conditions selected, the organisms exposed, the timing of exposure and precisely which effects are measured and over what timeframe. ii. doses considerably below 'no effect levels' for survival could nevertheless be causing significant impairment to health and/or reproductive success. iii. chemicals present in mixtures at levels below established thresholds for effects may, in combination, induce significant toxicological responses. Under the Council's current proposal, companies will be granted authorisations for some uses of CMRs and endocrine disruptors, even if safer alternatives without these properties are already on the market. The high level of evidence required for identification of substances as being of equivalent concern represents an additional weakness in the Council approach. Instead, a requirement (along the lines of the Parliament's proposals) to address the availability of alternatives in all cases, to use them when available and to initiate their development when not, represents a more robust, defensible and protective approach to the management of 'substances of very high concern'. The possibility for authorisation of essential uses would remain, while all avoidable uses and exposures would progressively be prevented and sustainable innovation supported. In the long run, this can only lead to a more sustainable future for the chemical industry in Europe, as well as delivering benefits of increased protection for our environment and health for generations to come.