Thyroid effects result in identification as SVHC substance

Resorcinol is the first substance to be concluded as a substance of very high concern (SVHC) based on endocrine disruption properties for human health because of its effects on the thyroid functioning.

NEWS UPDATE – 3 March 2022

As described below, the decision on resorcinol being considered as a substance of an equivalent level concern (i.e., an SVHC) based on its endocrine disrupting properties has been a challenging and complex regulatory process, leading to a split among EU members.

Most recent information on the formal regulatory decision-making process is that the voting pattern actually resulted in an outcome of ‘no opinion’ rather than the ‘positive vote’ previously reported on the Comitology Register. The Register was updated accordingly to reflect this interpretation following inter-services consultation within the Commission.

An update on the way ahead for resorcinol will be included in the next DHI newsletter. However, this outcome means that there is currently no mandate to have resorcinol listed as an SVHC.      


Resorcinol is a high-volume compound used in diverse industries such as cosmetics, medical products, cars and other industrial applications.

Complicated evaluation process
The evaluation of possible endocrine disrupting effects is very complex - especially for thyroid effects - and needs to be performed in accordance with specific guidance documents (ECHA/EFSA – 2018). The impact of a chemical substance on the functioning of the endocrine system needs to be assessed in terms of observed adverse health effects in an intact organism, relating the adverse effects observed to an endocrine based mode of action.

In an Annex XV report by The French Agency ANSES, it was concluded that resorcinol influences the regulation of thyroid hormone concentration via the inhibition of an enzyme essential to hormone biosynthesis. It was also established that resorcinol induces adverse health effects as seen from clinical studies (hypothyroidism following high dermal drug exposure) and experimental tests by different routes of exposure. Furthermore, ANSES concluded that there is a biologically plausible link between the mode of action and the adverse effects.

ANSES’ Annex XV report: Proposal for Identification of a Substance of Very High Concern

Although a substance can be identified as an endocrine disruptor, no specific CLP classification for endocrine properties exists so far. This makes it difficult to assess if an adverse health effect represents an equivalent level of concern (ELoC) to a CMR* substance, thereby fulfilling the criteria for SVHC identification according to article 57(f) of REACH. Consequently, evaluation of possible endocrine disruptors is performed on a case-by-case study, which was also done for resorcinol.

Split among EU members
The complexity in the evaluation of resorcinol was reflected in the regulatory process where ECHA’s Member State Committee failed to unanimously support the SVHC identification. It was then up to the European Commission to finally conclude on resorcinol. At first a disagreement was seen, but in the end resorcinol was concluded to be an SVHC substance by the European Commission.

For more information on endocrine disruptors and thyroid effects, please contact:

Brian Svend Nielsen
Tel +45 4516 9140

*CMR: carcinogenic, mutagenic or toxic to reproduction