Mecrilate

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Additional information

In Annex VIII of the REACH regulation, a screening test for reproduction toxicity/developmental toxicity is requested for substances produced or imported in a tonnage band of >10-100 t/a. In the case of methyl 2-cyanacrylate (MCA), a test according to OECD 422 or 421 was omitted for the following reasons:

1.      Test of the MCA monomer (substance to be registered) is technically not feasible:
Tests in aqueous media with MCA with the intent to determine effective concentrations or no effect concentrations cannot be performed due to technical reasons based on the chemical properties of the monomer. In presence of moisture, MCA polmerizes within seconds (inherent property of MCA-based instant glues). Thus, a defined effective concentration cannot be derived.

2.      MCA polymer induced no effects on fertility or developmental toxicity:
An indirect evaluation of potential adverse effects could be done on the basis of tests with the MCA polymer. The polymer itself is not bioavailable, but might be partly degraded to the MCA monomer or further degradation products if applied orally. Based on two repeated dose studies with rats or dogs, no effect on gonads or accessory organs were observed up to the highest dose tested (200 mg/kg b.w./d). It should be taken into account that application of higher doses of the MCA polymer would not necessarily lead to higher internal doses of the MCA monomer, which is further degraded to formaldehyde and methyl 2-cyanoacetate. In a study with the homologue butyl 2-cyanoacrylate (BCA) polymer, weaning rats received up to 6400 mg/kg b.w./d by food for ten days. No adverse effect on development was observed following a 90 day observation period.

3.      Exposure is limited, no consumers are exposed:
MCA is not foreseen for consumer use, only for applications at the industrial or professional workplace. There, strict risk management measures (RMM) are implemented to avoid contact with skin, eyes and the respiratory tract. These RMM are triggered by local effects, i.e. the irritation potential of MCA. Even if MCA gets accidentally in contact with skin, it will immediately polymerize and be no longer available for dermal penetration. Therefore, a very low bioavailability after dermal contact is expected.