Plenary Session of the MAK Commission 2026
Challenges arising from insufficient availability of data on relevant substances and review of the anniversary event marking the Commission’s 70th anniversary / A total of 70 new publications in 2025
The members, permanent guests and invited guests of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) met in Bonn on 12 March 2026 for this year’s plenary session and jointly looked back on the past year.
On 1 October 2025, an Open Science Day was held at the Futurium in Berlin to mark the (interner Link). On this occasion, the Commission presented a wide range of topics related to hazardous substances at the workplace and provided insights into its work for members of the public interested in science. The event attracted considerable interest, clearly demonstrating the Commission’s societal relevance and its importance for occupational health protection. A (interner Link) about the work done by the Commission was also produced in connection with the event.
While anniversary celebrations were a dominant feature of the past year, the Commission’s substantive work continued with great commitment. The Commission’s work has always focused on the scientific recommendation of threshold limit values for substances relevant to the workplace. This work is based on the analysis and integration of all available information, findings and studies relating to a given substance. One particular challenge in this regard is the fact that the data available is frequently insufficient. There is an increasing lack of toxicological studies(Popup Link) and, in particular, findings relating to effects in humans, especially when it comes to highly sensitive parameters of toxic effects. One reason for this is the declining role of toxicological research within the research system as a whole. Deriving exposure limits essentially requires the combination of findings obtained from very different models and species. In some cases, it is necessary to work with correlations or draw on similarities between substances. This complex integration of datasets and scientific findings is demanding and can only succeed through collaboration between different disciplines within the Commission. Ideally it is possible to identify the mechanism of action of the respective substance. This then also enables a risk-based assessment of the substance to be carried out and protective exposure limits to be recommended.
In recent years, numerous alternative approaches to substance assessment have also been developed. The Commission previously issued a (Download) on the prospects and limitations of these so-called New Approach Methods (NAMs), which include in particular data-based and AI-based simulation approaches as well as high-throughput testing systems. In addition, extensive environmental epidemiological cohort studies are available which, drawing on statistical methods, could also be used for the assessment of hazardous substances at the workplace in some cases. A separate working group within the Commission is looking into this issue. As such, the past working year was also dedicated to the continuous expansion of the Commission’s expertise and its engagement with new methodological approaches in order to assess the hazard potential of as many relevant substances as possible despite the limited availability of data.
The reports issued by the Commission’s working groups clearly demonstrated that this distribution of tasks contributes to both the efficiency and the high quality of the results. Through engagement with issues such as percutaneous absorption, sensitisation, inhalation-related and carcinogenic effects, as well as possible effects on the germ line, each of which is examined within the respective working group, the effects of substances can be assessed comprehensively and effective approaches for their health-protective handling can be described. Supplemented by the working groups concerned with substance measurement, this results in scientific recommendations that can be translated directly into occupational health and safety measures.
Looking back on the past year, several particularly complex assessments can be highlighted.
The MAK value for the respirable fraction of manganese and its inorganic compounds was re-evaluated taking welding studies into account, as welding is regarded as one of the most widespread sources of occupational exposure in Germany. A large number of studies were reviewed and assessed collaboratively by several working groups. Ultimately, the decision was taken to raise the MAK value for the respirable fraction from 0.02 mg/m³ to 0.05 mg/m³.
Melamine is an important raw material used in the production of melamine resins, which are in turn utilised as plastics or adhesives. Several years ago, a mass poisoning incident in China caused by contamination of milk and milk powder with melamine led to considerable public concern as well as concern among occupationally exposed individuals. The BAT value of 300 µg melamine/l urine is now an established health-based benchmark figure for human biomonitoring that can be used to assess exposure in individuals exposed to melamine. Based on this BAT value, it was also possible to derive a MAK value of 15 µg/m³.
Lithium is a substance which has been used therapeutically in psychiatry for decades in the treatment of bipolar disorder and recurrent depressive episodes, but it is also an essential component of modern technologies and therefore contributes to increasing occupational exposure among employees: a further health-based guideline for assessing exposure was established here with the derivation of a BAT value of 0.7 mg lithium/l serum.
Following completion of the comment phase, the results of the Commission’s work were again made available last year in open access to the research community and the public on the publication platform “MAK Collection”, both as the List of MAK and BAT Values and as the journal The MAK Collection for Occupational Health and Safety. The first publications are now also available in PMC and PubMed. A total of 70 publications were issued in 2025, including 40 MAK and 10 BAT (externer Link), descriptions of 10 air analysis methods and 10 biomonitoring methods. This large number of publications once again highlights the high level of voluntary commitment on the part of all those involved in the Commission’s work. For the first time, no comments or queries were submitted during the public consultation phase that precedes the final publication of the results, providing impressive confirmation of both the high quality and the broad acceptance of the findings. At the heart of the Commission’s capacity to function is its Scientific Secretariat: its highly competent research activities and the discussion papers it prepares form the basis for the Commission’s work. Last year also saw the successful establishment of an alternative funding model for the Secretariat through the conclusion of an agreement between KIT and the DFG. This will ensure more sustainable and appropriate working conditions for staff in the long term.