Plenary session of the MAK Commission 2022
Reflection on the use of new approach methods in the assessment of occupational substances/ Dynamic development of European discourse relevant to occupational health and safety
The plenary session of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) was held on 17 March 2022. All of the Commission’s sessions since the start of the pandemic have been held in a virtual format, yet the Commission made profitable use of the new opportunities even if personal interactions are indispensable factors in maintaining trust and cohesion. Complex matters or issues are now consistently discussed in advance in smaller groups. This has resulted in an acceleration of the discussion process and has reduced the number of review cycles. The virtual format has moreover enabled the exchange with international colleagues to be realised more easily and thus enhanced.
This meant that Professor Dr. Christopher Portier (Maastricht University) could be attracted to join a debate about the statistical interpretation of environmental health data and its application to the risk identification of carcinogenic substances. Dr. Russell Thomas, Director of the National Centre for Computational Toxicology at the US Environmental Protection Agency and Dr. Katie Paul Friedman, a toxicologist from this institute, were able to take part in a debate about the integration of complex high-throughput data for the toxicological evaluation of substances. In the past year, the commission’s attention was also much more strongly focused on the so-called new approach methods. These methods mainly involve the pursuit of data-based or simulation approaches, but cell-based high-throughput test systems are also increasingly being developed to replace animal experimental approaches where feasible. The methodical development in this area is extraordinarily dynamic. It requires intensive engagement with quality assurance processes and risk assessments relating to these approaches. No wonder then that this year’s plenary talk also addressed this topic. Professor Dr. Ellen Fritsche from the IUF – Leibniz Research Institute for Environmental Medicine in Düsseldorf reported on the latest research findings regarding the establishment of in vitro approaches regarding neurotoxicological issues related to foetal development, which initiated an intense and lively discussion.
The reports by the Commission’s working groups clearly reveal the value of the substantive division of labour relating to comprehensive evaluation of the substances, and the intensity of the interactions between the working groups. The Commission has also set health-based limit values for carcinogenic metal compounds, insofar as the findings on the impact mechanism make this possible. Vanadium and its inorganic compounds are a good example of this. Intense collaboration between the working groups “MAK values and classifications”, “Dusts”, “BAT values”, “Carcinogenesis”, “Epidemiology and statistics”, “Neurotoxicity and sensory systems” and “Developmental toxicity” enabled a new assessment to be made. The new working groups “Inflammation parameters”, “Neurotoxicity and sensory systems” and “Epidemiology and statistics” established in 2019 have already made important contributions to conceptual issues and the assessment of individual substances, and this enabled their first concrete contributions to be incorporated into the MAK and BAT values list.
The derivation of all the Commission’s findings was as always comprehensively documented. After the comment period has been completed, they will be openly accessible to the academic community and the public at large via the new platform set up with the support of ZB MED. This platform is intended to serve not only as a document repository, but also to ensure the re-usability and connectedness of the results. The publications are therefore prepared in such a way that user-oriented search functions can take effect and interoperability with other relevant databases is guaranteed.
The release of a total of 133 publications, the evaluation of 29 substances, the derivation of 18 MAK and BAT values, and the description of 27 methods clearly demonstrate the high level of commitment invested by the Commission’s members and guests. This level of performance would not however have been possible without support from the Commission’s research secretariat. This high quality work and the draft texts that it formulates are only feasible because of its highly competent research. In this context it is also worth mentioning the recommendation to alter the MAK value for synthetic amorphous silica. It has previously been assumed that amorphous substances generally pose only a comparatively low hazard potential. Yet new studies have now revealed adverse effects even at lower concentrations, which has resulted in adjustment of the MAK value.
The appointment of Andrea Hartwig, Chairperson of the Commission to the European Union’s Expert Group High Level Round Table on the Chemicals Strategy for Sustainability, will lend more weight to risk-based chemical assessment and research-based limit determination. The MAK Commission is also cooperating with the OECD to work intently with European partners in helping to ensure that research findings remain the central basis for regulatory approaches in occupational health and safety.