Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Stability

The hydrolysis of cyclohexylidenebis[tert-butyl] peroxide in different aqueous buffer solutions (pH = 4, 7 and 9) at 5, 15 and 25 °C was investigated using HPLC-UV. Measurements revealed a fast hydrolysis of cyclohexylidenebis[tert-butyl] peroxide (half-live: 27 hours) at pH = 4 and 25 °C. The degradation products of the hydrolysis of cyclohexylidenebis[tert-butyl] peroxide are tert-butyl hydroperoxide and cyclohexanon.

Biodegradation

The ready biodegradability of cyclohexylidenebis[tert-butyl] peroxide was evaluated using a 28-day modified Sturm test according to EU method C.4 -C and OECD guideline no. 301 B. The biodegradation of cyclohexylidenebis[tert-butyl] peroxide totalled 5 % at the end of the test. Therefore, cyclohexylidenebis[tert-butyl] peroxide was non readily biodegradable in the 28-day modified Sturm test.

The performance of simulation tests for biodegradation in water and sediment is scientifically unjustified.

REACH Regulation (EC) No 1907/2006, Annex IX, Sect. 9.2.1.4, Col. 2, states as follows:

“9.2.1.4: The study need not to be conducted:

- if the substance is readily biodegradable, or

- if direct and indirect exposure of sediment is unlikely. ”

Direct and indirect exposure of the test item to water and sediment is highly unlikely. Due to the unstable nature of organic peroxides, it can be assumed that upon contact with water and organic matter, the test item undergoes rapid degradation resulting in the formation of respective alcohols and acids. In addition the low adsorption coeffcient (log Koc) of the test item (log Koc=2.69) indicates a low dwell time of the test item in soil and thus a low exposure.Therefore simulation testing for biodegradation in water was considered not scientifically justified.

 

The performance of tests for biodegradation in soil is scientifically unjustified.

REACH Regulation (EC) No 1907/2006, Annex IX, Sect. 9.2.1.3, Col. 2, states as follows:

“9.2.1.3: The study need not to be conducted:

- if the substance is readily biodegradable, or

- if direct and indirect exposure of soil is unlikely. ”

Direct and indirect exposure of the test item to soil is highly unlikely. Due to the unstable nature of organic peroxides, it can be assumed that upon contact with soil and organic matter, the test item undergoes rapid degradation resulting in the formation of respective alcohols and acids. In addition the low adsorption coeffcient (log Koc) of the test item (log Koc=2.69) indicates a low dwell time of the test item in soil and thus a low exposure. Therefore simulation testing for biodegradation in soil was considered not scientifically justified.

Bioaccumulation

The performance of a test for bioaccumulation in aquatic species, preferably fish, is scientifically unjustified.

REACH Regulation (EC) No 1907/2006, Annex IX, Sect. 9.3.2, Col. 2, states as follows:

“9.3.2 The study need not be conducted if:

- the substance has a low potential for bioaccumulation (for instance a log Kow <= 3) and/or a low potential to cross biological membranes, or

- direct and indirect exposure of the aquatic environment is unlikely. ”

Direct and indirect exposure of the test item to water is highly unlikely. Due to the unstable nature of organic peroxides, it can be assumed that upon contact with water and organic matter, the test item undergoes rapid degradation resulting in the formation of respective alcohols and acids. Therefore, the test substance was considered to have no bioaccumulation potential.

Transport and distribution

Using the HPLC method the adsorption coefficient (Koc and Log Koc) of the test item was estimated to be 488 and 2.69, respectively.