Classifying two methacrylates as sensitising and irritant substances

Two substances that can cause allergies and irritation in many professionals

2-hydroxypropyl methacrylate (HPMA) and 2-hydroxyethyl methacrylate (HEMA) are used in many products such as adhesives, cosmetics and personal care products. Their irritation and sensitisation potential, in particular for the respiratory tract, has been assessed by ANSES with the aim of proposing a harmonised classification at European level.

While HPMA is not, for the time being, subject to any harmonised classification under the CLP Regulation, HEMA is currently classified for its ability to cause skin and eye irritation and skin allergies.

Several scientific publications also identify methacrylates as causative agents of occupational asthma. In particular, a review of Finnish data on the monitoring of occupational diseases noted respiratory hypersensitivity reactions in workers exposed to HEMA and HPMA. 

The identification of methacrylates as respiratory irritants is also based on the fact that:

•  other methacrylates are classified for this property and they metabolise to methacrylic acid, a substance classified for its corrosive properties;
•  the toxicokinetic and physico-chemical data on HEMA and HMPA indicate that these two substances are capable of reaching the respiratory tract and giving rise to the release of methacrylic acid.

Lastly, concerning HPMA, its skin sensitising properties have been observed in a number of epidemiological studies, and an in vivo study in rabbits caused severe eye irritation.

For all these reasons, ANSES therefore recommends that HEMA and HPMA be classified and labelled as follows under the CLP Regulation:

• “Causes skin irritation; Category 2 (H315)”, exclusively for HEMA based on its current classification,
• “Causes serious eye irritation; Category 2 (H319)”,
• “May cause an allergic skin reaction; Category 1 (H317)”,
• “May cause allergy or asthma symptoms or breathing difficulties if inhaled; Category 1 (H334)”,
• “May cause respiratory irritation; Category 3 (H335)”.

Harmonised classification proposals submitted for public consultation

The harmonised classification proposals for HEMA and HMPA were submitted for public consultation on the ECHA website on 13 March 2023, for a two-month period, to give all stakeholders the opportunity to present their comments, scientific arguments and any additional information at their disposal. Comments can be sent via a dedicated form on the ECHA website.

Following this consultation stage, ANSES will be asked to respond to the comments received. The initial proposal, comments and ANSES's responses to them will then be placed before ECHA’s Committee for Risk Assessment, which will issue an opinion on the classification of HEMA and HPMA.

Based on this opinion, the European Commission will draft regulatory texts allowing the proposed classifications to be included in the CLP Regulation.

Box: Regulation on Classification, Labelling and Packaging (CLP)

Regulation (EC) No 1272/2008 on the classification, labelling and packaging of substances and mixtures, known as the CLP Regulation, is the legislation in force in the European Union to protect workers, consumers and the environment against the risks posed by chemicals. In particular, it aims to identify any hazards posed by a substance or substance mixture due to its physico-chemical properties and its effects on health and the environment.

This Regulation defines how these substances and mixtures must be classified, labelled and packaged. It also has impacts on other European regulations, possibly leading to the prohibition or substitution of substances or mixtures depending on their hazard characteristics.

Once a substance or mixture has been classified with regard to the identified hazards, appropriate labelling informs the user about these hazards through pictograms and safety data sheets. ECHA is responsible for implementing the CLP Regulation.