Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Available data indicate that, cyclohexyl methacrylate is acutely harmful to aquatic species.

LC50(96h) Danio rerio = 590 mg/L (nominal)

EC50(48h) Daphnia magna = 33.9 mg/L (measured)

ErC50 (72h) Pseudokirchneriella subcapitata = 12.5 mg/L (measured)

ErC10 (72h) Pseudokirchneriella subcapitata = 5.49 mg/L (measured)

No chronic data on fish and invertebrates of cyclohexyl methacrylate is available. However, for the structurally related methyl methacrylate (CAS: 80-62-6) as well as the hydrolysis product methacrylic acid (CAS: 79-41-4) reliable chronic tests were conducted on Danio rerio and Daphnia magna, indicating no chronic hazard.


Methyl methacrylate

NOECreproduction(21d) Daphnia magna = 37 mg/L (measured)

NOECreproduction(35d) Danio rerio = 9.4 mg/L (measured)

Methacrylic acid

NOECreproduction(21d) Daphnia magna = 52 mg/L (measured)

NOECreproduction(35d) Danio rerio = 10 mg/L (nominal)

Since cyclohexyl methacrylate is readily biodegradable a rapid disappearance from the water column is anticipated and chronic aquatic exposure towards this substance becomes unlikely.


Furthermore, cyclohexyl methacrylate shows no harmful effects towards aquatic microorganisms (EC20 = ca. 450 mg/L, domestic activated sludge, OECD TG 209).Therefore, the inhibition of the degradation activity of activated sludge is not anticipated when cyclohexyl methacrylate is introduced into biological treatment plants in appropriately low concentrations.

PNEC calculation is done based on the acute data from the registered substance only as a worst case. Nevertheless, data with the hydrolysis product methacrylic acid and the structurally related methyl methacrylate together with the ready biodegradability of the registered substance show the lack of any adverse toxic chronic effects.