Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

There is no data on 1,4-bis[1-(tert-butylperoxy)-1-methylethyl]benzene. A read across approach is proposed with 1,3 (or 1,4)-bis[1-(tert-butylperoxy)-1-methylethyl]benzene.

The in vitro rate of metabolism was determined for [1,3(or 1,4)- Phenylenebis(1-methylethylidene)] bis[tert-butyl] peroxide using the in vitro metabolism trout liver S9 essay (this approach is not yet an established guideline and is still being developed. Nevertheless, the general approach appears to be scientifically valid and is under development by the Bioconcentration Working Group of ILSI/HES).

This organic peroxide metabolized rapidly under biologically active conditions with a metabolic half- life of 67 minutes or 1.13 hours. This data was used to extrapolate in vivo rate constants of metabolism or kMET of 0.184 day-1 or 0.475 day-1 using hepatic portal blood flow or hepatic portal and arterial blood flow, respectively. The use of these kMET values in conjunction with the Gobas model dropped the calculated BCF from 45,294 kg day-1 (assuming no metabolism) to 536 or 209 kg day-1. The impact of metabolism on [1,3(or 1,4)- Phenylenebis(1-methylethylidene)] bis[tert-butyl] peroxide drops the BCF to less than the action level of 2000 (Reach Criteria) and should not be considered to have significant bioaccumulation potential.