Ethyl methacrylate

Toxicity to microorganisms

Description of key information

Toxicity to microorganisms: 30-min EC50 1000-1800 mg/L (activated sludge)
The inhibition of the degradation activity of activated sludge is not anticipated when introduced in appropriate concentrations.

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L

Additional information

Activated sludge inhibition data (ISO 8192) are available for ethyl methacrylate and indicate a 30-min EC50 of 1000 -1800 mg/L. Further MAA and the lower alkyl methacrylate category members up to the BMA isomers show a low toxicity to micro-organisms while for 2-EHMA no toxicity has been observed up to and above the limit of solubility. See the following table:

Summary of effects on micro-organisms

	Species	Results	Remarks	Reference
MAA	Pseudomonas putida	16h EC10= 100 mg/l	16 h growth inhibition test, sensitive species	Hanstveit, 1992
MMA	Pseudomonas putida	16h EC3= 100 mg/l	16 h growth inhibition test, sensitive species	Bringmann and Kühn, 1976, 1980ª
MMA	Activated sludge	14 d NOEC = 100 mg/l	Ready biodegradability test, OECD 310 C MITI (I)	CITI, 1992
EMA	Activated sludge	30 min EC50= 1000- 1800 mg/l	ISO8192 (OECD 209) respiration inhibition test	Hund and Fabig, 1989
n-BMA	Pseudomonas putida	18h EC10≥ 253.6 mg/l	18 h growth inhibition test, sensitive species	Fabig and Hund, 1988
i-BMA	Pseudomonas fluorescens	16h EC10> 281 mg/l*	16 h growth inhibition test	Rump(Fresenius), 1988
2-EHMA	Activated sludge	21 d NOEC = 100 mg/l	OECD 301 C Modified MITI (I) Test	CERI, 1998b

* No growth inhibition with saturated solution