Benzyl methacrylate

Endpoint summary

Description of key information

LC50 (96h) fish: 4.67 mg/l

EC50 (72h) algae: 2.28 mg/l

EC10 (72h): 1.08 mg/l

EC10 (21d) Daphna magna: 1.03 mg/l

Additional information

Freshwater aquatic toxicity studies with BNMA were conducted in fish, invertebrates, and algal species.

 

Short-term toxicity to fish

In a 96-h acute toxicity study similar to OECD Guideline 203, Pimephales promelas (Fathead minnow) were exposed to BNMA at nominal (measured) concentrations of 0, 3.54 (3.02), 5.45 (4.54), 8.38 (7.03), 12.9 (11.2) and 19.9 (17.1) mg a.i./L under flow through conditions.

The 96-h LC50 was 4.67 mg a.i./L (95% C.I. 4.25 - 5.13 mg a.i./L).  The EC50 value, based on sublethal effects, was 4.48 mg a.i./L.  Sublethal effects of loss of schooling behaviour, loss of equilibrium and hypoactivity were observed in the groups exposed to nominal 5.45 mg/L and higher of BNMA.

 

Short-term toxicity to aquatic invertebrates

No data on short-term toxicity of BNMA are available. In accordance with REACH regulation Annex VII, 9.1.1., column 1, long-term toxicity data are provided instead.

 

Toxicity to aquatic algae

In a 72 hour toxicity study, the cultures of Desmodesmus subspicatus CHODAT SAG 86.81 were exposed to BNMA at measured concentrations of 0 (control), 0.436, 0.899, 1.84, 4.11 and 7.67 mg/L under static conditions in accordance with the OECD guideline 201 (adopted 23 March 2006).

The EC10 and EC50 values based on growth rate were 1.08 mg/L and 2.28 mg/L, respectively. Microscopic evaluation of the cells at start and end of the incubation period revealed no morphological abnormalities.

 

Long-term toxicity to fish

Long-term testing in fish is waived for BNMA. The risk characterisation shows that the PEC/PNECaqua ratio for the aquatic environment is <1, indicating no need for further information or testing. According to REACH regulation Annex IX, 9.1. column 2, long-term toxicity testing shall only be considered when the chemical safety assessment indicates the need for further investigations. Thus, no long-term toxicity testing is required for BNMA.

 

Long-term toxicity to aquatic invertebrates

The 21-day-chronic toxicity of BNMA to Daphnia magna Straus was studied under static renewal conditions according to OECD guideline 211 (adopted 3 October 2008). Daphnids were exposed to control and test chemical at measured concentrations of 0.291, 0.926, 4.21, 11.7 and 26.3 mg/L. 

The 21 d EC10 based on reproduction was 1.03 mg/L. The sublethal effects included were reproduction rate and appearance of first brood. The most sensitive endpoint was the reduction of the reproductive output. 

The 21 d EC 50 based on parental mortality was 15.3 mg/l

 

Toxicity to microorganisms

Toxicity to microorganisms testing is waived for BNMA since it is classified as readily biodegradable at an application concentration (13.3 mg/L), which is greater than the predicted environmental concentration (PEC) in the influent of the sewage treatment plant (STP).

 

 

In conclusion, the lowest aquatic toxicity value for BNMA was the 21 d EC10 of 1.03 mg/L, based on the long-term toxicity study with Daphnia magna.