Reaction products of methacrylic acid and 2,2'-[(1-methylethylidene)bis(4,1-phenyleneoxymethylene)]bisoxirane

Endpoint summary

Additional information

Small Vinyl Ester was tested in a fresh water algal growth inhibition test, the EC50 for both the growth rate reduction and the yield inhibition were beyond the range tested, and it is concluded to exceed the nominal concentration of 100 mg/L (TWA concentration of 1.1 mg/L). With 9.8% reduction of the growth rate at the highest test concentration of 1.1 mg/L (measured), the NOEC/EC10 is arbitrary set at 1.1 mg/L (measured).

Small Vinyl Ester was tested in an activated sludge inhibition test. Under the conditions of the test the 3-hour EC50 was found to be > 100 mg/L, based on duplicated measurements of the inhibition of the respiration rate of activated sludge. Hence, Small Vinyl Ester was found to be non-toxic to waste water bacteria (activated sludge) at a loading rate of 100 mg/L.

In a short-term fish toxicity test the LC50 was found to be higher than 100 mg/L (nominal concentration) for Small Vinyl Ester, as estimated from the absence of mortality in the test group using binominal theory to calculate the level of confidence of 99%. This was confirmed with a structural analogue (Modified Small Vinyl Ester). No toxicity in fish was found at the water solubility limit of Modified Small Vinyl Ester, which is 7 mg/L weighted average based on the solubilities of the two main constituents, bisGMA (0.42 mg/L) and monomaleic bisGMA (37.6 mg/L). Small Vinyl Ester does not contain monomaleic bisGMA. Thus, the water solubility limit is approximately 0.42 mg/L based on bisGMA. It is concluded that Small Vinyl Ester does not induce short-term toxicity in fish at its water solubility limit.

Short-term toxicity in Daphnia was assessed using data (read-across) from a structural analogue (Modified Small Vinyl Ester). Modified Small Vinyl Ester induced less than 30% immobility in Daphnia at its water solubility limit, which is approximately 7 mg/L weighted average based on the solubilities of the two main constituents, bisGMA (0.42 mg/L) and monomaleic bisGMA (37.6 mg/L).

Small Vinyl Ester does not contain monomaleic bisGMA. Thus, the water solubility limit is approximately 0.42 mg/L based on bisGMA. It is concluded that Small Vinyl Ester will induce less than 30% immobility in Daphnia at its water solubility limit (0.42 mg/L).

The above-mentioned tests document that Small Vinyl Ester is non-toxic or low toxic (Daphnia) in aqueous species. In addition Small Vinyl Ester is unlikely to reach water. Small Vinyl Ester is a highly viscous prepolymer, which is placed on the market as an approximately 50% solution in a reactive diluent for industrial and professional use only. Thus, direct and indirect exposure of water, and consequently long-term effects are judged to be unlikely, cf. Section 13 'Environmental exposure assessments for exposure-based waiving'. Thus, long-term toxicity testing on fish and Daphnia is waived with reference to REACH Annex IX section 9.1, column 2 based on exposure considerations and no or low toxicity to aquatic organisms. See Sections 9 and 10 of the CSA for further details.