Image from Fera Science Limited (Fera)

The REACH (Registration, Evaluation, Authorisation and restriction of Chemicals) timeline continues relentlessly harmonising chemical information requirements and placing the burden of proof (and cost) on the manufacturers and importers.

While the data gathering exercise for those substances manufactured and/or imported in the highest amounts and those considered the most hazardous have been dealt with during the 2010 and 2013 registration deadlines, the focus has shifted to the May 2018 deadline for those substances in the 1-100 tonnes per year category. This will have significantly more registrations than previously experienced, and interestingly, European Chemicals Agency (ECHA) have stated that it will include many more inexperienced registrants from non-chemical industry sectors. Some consortia could consist of just one organisation. This will not only place a financial burden on the organisations involved but may stretch them technically, the extent of which will be dependent on the substance information already available, whether any data requires generating and any individual complexities of the substance.

While Substance Information Exchange Forums (SIEF) and consortia work towards the 2018 registration deadline, substances that have been identified as ‘potential concern’ are undergoing substance evaluation as part of the Community Rolling Action Plan (CoRAP). Substance evaluation may be triggered by a number of concerns including: potential for human and/or environmental exposure, persistence, bioaccumulation and toxicity (PBT), very persistent and very bioaccumulation (vPvB), endocrine disruption and/or carcinogenicity, mutagenicity and/or reproductive toxicity. During this process substances suspected to pose a risk to human and/or environmental health are evaluated by Member State competent authorities which may lead to requests for further information before a decision is finalised. The requests from CoRAP pose some of the most interesting challenges for the chemical safety community due to the diverse nature of these compounds.

Over the past five or six decades, since the publication of Silent Spring, environmental chemical risk assessment has been dominated by the requirements of the agrochemical industry, with the development of a comprehensive and technical program of experimental testing and risk assessment science. Sectors without this environmental risk history, have subsequently adopted the established methodologies, guidelines and principles. While chemical groups such as pharmaceuticals can be different to agrochemicals there is some overlap of the chemical space. Deploying ‘standard’ methodologies to generate the data required will be challenging for the chemically diverse range of substances included in CoRAP, some of which are very different from the substances for which standard methodologies were first developed. This will make satisfying the usual validity criteria of standard studies, technically very challenging and in some cases impossible.

Substances with very low water solubility may be problematic. Where significant exposure of environmental surface waters is expected then investigations of the rate and route of degradation in water/sediment systems may be required (e.g. OECD 308). The protocol for this type of study usually requires substances to be applied at concentrations below the solubility limit and also requires detection limits of one percent of the applied concentration, which is often unachievable for substances applied at low levels due to water solubility restrictions. This leaves two choices: either operate the study at application levels above the water solubility or increase the acceptable minimum lower quantification limit. Neither of these options is ideal but pragmatic solutions and acceptance of those solutions will be required.

Funding organisations and laboratories have risen to the challenge of developing experimental methodologies for substances with challenging characteristics, but some of these projects are on-going and/or yet to be accepted by regulators. In the meantime we will need to work collaboratively and supportively, and accept pragmatic solutions to these challenges.

* Image from Fera Science Limited (Fera)