ANSES conducts expert appraisals on the hazards and risks of chemicals under the REACh Regulation and recommends appropriate management measures in this context. This Regulation stipulates that chemicals with evident endocrine-disrupting properties can be identified as substances of very high concern (SVHC). As part of France's National Endocrine Disruptor Strategy (SNPE), the Agency assesses substances with potentially harmful effects on endocrine systems. The effect of resorcinol on thyroid hormone synthesis was examined in this regard.
Serious effects of concern to human health
On the basis of the available experimental and clinical data, ANSES's experts established that this substance meets all the hazard criteria necessary for it to be defined as an endocrine disruptor according to WHO criteria and the 2013 recommendations of the European Commission, namely:
- an endocrine mode of action: there is solid evidence of resorcinol's effect on the regulation of thyroid hormone concentration via the inhibition of an enzyme essential to hormone biosynthesis;
- adverse health effects: identification of severe hypothyroidism during clinical observations following high dermal drug exposure to this substance in humans (goitre, loss of energy, generalised oedema, weight gain, and in some cases depression); thyroid effects induced in experimental tests by different routes of exposure;
- there is a biologically plausible link between the mode of action and the adverse effects: consistency between the inhibitory action of resorcinol and the severe hypothyroidism observed.
Since the evidence has been established in humans, ANSES concludes that resorcinol is a proven endocrine disruptor.
This property means that resorcinol is a concern because exposure to this substance can lead to severe health effects. Depending on the exposure conditions, this substance could trigger or aggravate hypothyroidism symptoms. Moreover, even mild hypothyroidism in pregnant women can cause irreversible neurodevelopmental disorders in the unborn child. Lastly, it is difficult to establish a safe exposure dose, especially in vulnerable populations such as those with latent hypothyroidism or during critical periods of foetal development, for example.
For these reasons, ANSES considers that the endocrine-disrupting properties of resorcinol present a sufficient level of concern to meet the criteria for identification as a substance of very high concern (SVHC) under the provisions of the European REACh Regulation.
The identification dossier put forward by ANSES has been submitted for public consultation on the website of the European Chemicals Agency (ECHA) until 17 April. Link to the dossier: echa.europa.eu/documents/10162/53d2eb0e-b0e8-fabb-b4b0-a56c246cb0a3
Consequences of identification as a substance of very high concern
If identified as an SVHC, resorcinol will be added to the list of candidates for authorisation under REACh. This authorisation procedure will result in industry being required to notify ECHA of the substance's presence in manufactured or imported articles containing more than 0.1% resorcinol. SVHC identification also opens up the possibility of resorcinol being listed in Annex XIV of the REACh Regulation, which requires temporary renewable authorisation to be obtained for certain uses, leading to strict control of its use in Europe and encouraging substitution of the substance.
Additional investigations under way for the environment
The endocrine-disrupting properties of resorcinol may also have consequences for the environment. ANSES is therefore conducting a parallel assessment of potential adverse effects on species in the environment.