OO-tert-butyl monoperoxymaleate

Endpoint summary

Description of key information

Three trophic levels (fish, daphnia, algae) are covered by the acute toxicity data set. No chronic data are available.

Pseudokirchneriella subcapitata was observed to be the most sensitive species. The related 72-h ErC50 determined according to the OECD test guideline 201 (2006) was 4.24 mg/L.

Additional information

Short-term toxicity to fish:

Schwartz (2018): In a 96-h acute toxicity study according to OECD 203, zebra fish (Danio rerio) were exposed to OO-tert-butyl monoperoxymaleate at nominal concentrations of 0.0 (control) and 10 mg/L (nominal) under semi-static conditions (limit test). The NOEC value, based on mortality and sublethal effects, was ≥ 5.34 mg/L (measured concentration). The LOEC was > 5.34 mg/L (measured concentration). Sublethal effects were not observed.

Short-term toxicity to Daphnia magna:

Kretzschmar (2017): The 48–hr-acute toxicity of the test item to Daphnia magna Straus was studied under semi-static conditions according to OECD 202 (2003). Daphnids were exposed for 48 hr to a control containing no test substance, and OO-tert-butyl monoperoxymaleate at nominal concentrations of 38.1, 61.0, 97.7, 156.3 and 250.0 mg/L, corresponding to measured concentrations of 33.2; 55.2; 92.9; 153.8; 295.90 mg/L (geometric mean).

Mortality/immobilization and sublethal effects were observed daily. The 48-hr EC₅₀ was 191.16 mg/L. The 48-hr NOEC based on immobilization was 55.24 mg/L.

Short-term toxicity to aquatic algae (Pseudokirchneriella subcapitata):

Kretzschmar (2017): In a 72-hour algal growth inhibition test, cultures of Pseudokirchneriella subcapitata were exposed to OO-tert-butyl monoperoxymaleate at nominal concentrations of 0 (control), 1.1, 2.8, 7.4, 19.2, 50.0 mg/L, corresponding to measured concentrations of 0,0.33, 0.59, 1.38, 4.52 and 12.24 mg/L (geometric mean) under static conditions in accordance with the OECD Guideline 201 (2006), OECD 23 (2000) and under GLP. Results based on growth rate after 72 h were as follows: ErC50: 4.24 mg/L (95 % C.I.: n.d.); ErC10: 3.77 mg/L (95 % C.I.: 0.00 – n.d.); LOEC: 4.52 mg/L and NOEC: 1.38 mg/L.

Toxicity to microorganisms

Brunswik-Titze (2018): An OECD 209 Activated sludge inhibition test (2010) was performed with OO-tert-butyl monoperoxymaleate. The study was conducted to assess the inhibitory effect of the test item at a limit concentration of 100 mg/L (nominal) to microorganisms of activated sludge by measuring the respiration rate after adding a standard amount of synthetic sewage feed. An EC50 > 100 mg/L, a LOEC < 100 mg/L and a NOEC ≥ 100 mg/L were determined.

This shows that OO-tert-butyl monoperoxymaleate had no toxic effect on the total respiration rate of activated sludge microorganism at the concentration of 100 mg/L (nominal) after the exposure period of 3 hours.