[1,3(or 1,4)-phenylenebis(1-methylethylidene)]bis[tert-butyl] peroxide

Endpoint summary

Additional information

Acute and chronic studies are available for each trophic level:

 

Short term Toxicity to Fish: OECD Test Guideline 203 (1984). The LC50(96 h) was calculated to be 750 mg/L, with 95% confidence limits of 360 and 1570 mg/L. Based on the results of this study, [1,3(or 1,4)- Phenylenebis(1-methylethylidene)] bis[tert-butyl] peroxide would be classified as not dangerous to fish in accordance with the Directive 67/548/EC. However, given that during the test a layer of test substance remained visible on the surface of the test media in all test concentrations, the LC50 value should be handled with care. Moreover no analytical monitoring was performed during the test. Based upon the fact that no mortality was observed this test can be considered as valid with restrictions.

 

Short term Toxicity to Aquatic invertebrates: [1,3(or 1,4)-Phenylenebis(1-methylethylidene)]bis[tert-butyl]peroxide was not found to be acutely toxic to Daphnia magna when dispersed in water at a nominal loading rate of 1.0 mg/L equivalent to an initial mean measured concentration of 0.0219 mg/L. Consequently, the 48-hour EC50 value for [1,3(or 1,4)-Phenylenebis(1 -methylethylidene)]bis[tert-butyl]peroxide could not be calculated but must be >1.0 mg/L (>0.0219 mg/L). The “no observed effect loading rate” was 1.0 mg/L (0.0219 mg/L as initial mean measured concentration).

 

Short term Toxicity to freshwater algae: The acute toxicity of [1,3(or 1,4)-phenylenebis(1-methylethylidene)]bis[tert-butyl] peroxide was evaluated with Pseudokirschneriella subcapitata in a study performed in accordance with OECD testing guideline 201 and GLP requirements.

The algae were exposed to nominal test concentrations of 1 mg/L under static conditions during 72 hours. The mean measured concentrations were not maintained between 80 and 120 % of nominal. The test substance was not found to be acutely toxic toPseudokirchneriella subcapitata at a nominal loading rate of 1.0 mg/L, equivalent to an initial mean measured concentration of 0.0471 mg/L.

 

Chronic Toxicity to Aquatic invertebrates: Several OECD 211 studies are available. Under the optimized test conditions of a recent OECD 211 study (semi-static conditions with a daily renewal and a completely closed test vessels, no headspace, and light conditions reduced to the lower end of the optimal range), [1,3(and/or 1,4)-Phenylenebis(1-methylethylidene)]bis[tertbutyl] peroxide did not affect reproduction, growth and survival of Daphnia magna up to and including the highest tested concentration of nominally 40 μg/L corresponding to an average measured concentration of 11.4 μg/L after 21 days of exposure.

Chronic Toxicity to Fish : A recent OECD 210 study was performed to assess the possible lethal and sub-lethal effects of [1,3(and/or 1,4)-Phenylenebis(1-methylethylidene)]bis[tertbutyl] peroxide during the embryonic and early larval development of the fathead minnow. After several preliminary tests, this study was performed using completely closed test vessels, very limited headspace, and light conditions reduced to the lower end of the optimal range, in order to limit the loss of the substance by volatilization, adsorption or photodegradation. The results led to the conclusions that [1,3(and/or 1,4)-Phenylenebis(1-methylethylidene)]bis[tertbutyl] peroxide did not affect the hatching success (embryonic survival), survival of larvae and the growth of the exposed larvae up to the highest achievable concentration which is nominally 40 µg/l (water solubility limit) corresponding to average measured concentrations of 31 µg/L. 

To summarize no effect of 1,3(or 1,4)-phenylenebis(1-methylethylidene)]bis[tert-butyl] peroxide was observed up to the highest achievable concentration for the available acute and chronic aquatic tests.