Bis(2,4-dichlorobenzoyl) peroxide

Endpoint summary

Description of key information

Short and long term toxicity to fish

One OECD 203 test with Poecilia reticulata is available where the EC50 > 1000 mg/L (loading rate)

Long-term fish testing is waived

Short term toxicity to aquatic invertebrates

One OECD 202 GLP study is available.

In order to predict the effects of Bis (2,4-dichlorobenzoyl) peroxide in an aquatic environment, an acute toxicity test to Daphnia magna was conducted in accordance with OECD test guidelines and with the OECD Principles of Good Laboratory Practice. Some modifications to the guideline were applied due to inherent properties of the test chemical.

The toxicity of the test chemical to Daphnia Magna prepared as a Water Accommodated Fraction (WAF) was determined in a semi static system over an exposure period of 48 hours at a loading concentration of 100 mg/L.

Long term toxicity to aquatic invertebrates

A chronic Daphnia OECD 211 GLP study is available.

In order to predict the effects of Bis (2,4-dichlorobenzoyl) peroxide in an aquatic environment, a long-term toxicity test to Daphnia magna was conducted in accordance with OECD test guidelines and with the OECD Principles of Good Laboratory Practice. Some modifications to the guideline were applied due to inherent properties of the test chemical.

The toxicity of the test chemical to Daphnia Magna prepared as a Water Accommodated Fraction (WAF) was determined in a semi static system over an exposure period of 21 days at a loading concentration of 10 mg/L.

Due to a significant effect being observed (5.5% reproduction inhibition) the chronic toxicity of the test substance can be expressed as NOELR < 10 mg/L and EL₁₀is > 10 mg/L. A clear effect of the test substance is usually also supported by the secondary length endpoint. No significant difference in parent length was observed in this case.  

Due to the worst case approach of the testing (tested 10 x above the 1 mg/L chronic classification cutoff) and based on the data currently available, the substance should not be classified as toxic toDaphnia magna.

Toxicity to aquatic algae and cyanobacteria

In order to predict the effects of in an aquatic environment, an Algal Growth Inhibition test was conducted in accordance with OECD 201 test guideline and with the OECD Principles of Good Laboratory Practice. Some minor modifications to the guideline were applied due to inherent properties of the test chemical. These included preparing the test chemical as a Water Accommodated Fraction (WAF), minor changes in media components to help aid pH stability.

The toxicity of the test chemical to an exponentially growing culture of P. subcapitata was determined over an exposure period of 72 hours. A nominal loading concentration of 100 mg/L as a limit test was conducted. In addition to the testing of the water accommodated fraction in the standard manner (i.e. without un-dissolved material), the WAF vessel itself including any solid undissolved test chemical was also inoculated with algae and growth was monitored to allow additional data to be obtained.

No statistical difference in growth rate or biomass was detected in comparison to the control. The test substance was concluded as not toxic to algae at its maximum achievable solubility limit in the test medium.

NOELR >100 mg/L of test material. The EL10 (72h, (growth rate) > 100 mg/L

Toxicity to microorganisms

The EC10 and EC50 of 1,1,3,3-tetramethylbutyl 2-ethylperoxyhexanoate for activated sludge after 3 hours contact time are > 1276 mg/L.