Ethyl 2-cyanoacrylate

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Justification for type of information:

The substance ethyl 2-cyanoacrylate (EC 230-391-5) is a representative of the group of cyanoacrylate based reactive glues. Colloquially this type of glues is named ‘instant glues’ indicating that they cure within seconds to minutes. The polymerisation reaction starts with the reaction of traces of hydroxide ions with the activated double bond and leads to insoluble polymers within very short periods of time. The concentration of hydroxide ions originating from the autoprotolysis of ambient moisture or adsorbed water on surfaces (COH- = 10-7 mol/L) is sufficient to start the polymerisation reaction.

Waiving justification based on Annex VIII, REACH Regulation
According Annex VIII of the REACH Regulation a test can be waived if the test substance is e.g.
Chapter 9.1.3 Short-term toxicity testing on fish
• there are mitigating factors indicating that aquatic toxicity is unlikely to occur, for instance if the substance is highly insoluble in water or the substance is unlikely to cross biological membranes
Chapter 9.1.4 Activated sludge respiration inhibition testing
• there is no emission to a sewage treatment plant; or
• there are mitigating factors indicating that microbial toxicity is unlikely to occur for instance the substance is highly insoluble in water.
The typical application of instant glues is a dropwise application with instantaneous polymerisation in place. Thus, a significant release to sewage treatment plants is not to be anticipated. In all tests with contact to moisture the registered substance ethyl 2-cyanoacrylate (EC 230-391-5) is highly active or unstable with regard to the monomer. See chapter 5.6 Additional information on environmental fate and behaviour with information on the polymerisation velocity in contact with moisture. The monomer concentration after polymerisation in contact with water is very low and only traces are detectable (see Physical & Chemical Properties, Water Solubility) Therefore the reason to waive studies with unavoidable contact to moisture are fulfilled according Annex VIII of REACH regulation. The reaction product is a polymer which is not yet to be registered.
Conclusion
Due to the chemical properties of the registered substance ethyl 2-cyanoacrylate (EC 230-391-5) and based on justification requirements for waiving defined in Annex VIII REACH are not possible and not necessary.

Applicant's summary and conclusion

Conclusions:

Tests in aqueous media with ethyl 2-cyanoacrylate 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.

Executive summary:

Tests in aqueous media with ethyl 2-cyanoacrylate 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 ethyl 2-cyanoacrylate polymerises within seconds (inherent property of ethyl 2-cyanoacrylate based instant glues). Thus, very low determined monomer concentrations in water represent a non-steady state situation from which a defined effective concentration cannot be derived.