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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Administrative data

Description of key information

According to the Toolbox, compounds with this similar structure react by attack of the protein nucleophile on one of the central oxygen atoms, with a carboxylate anion acting as a leaving group. The central oxygen atoms of diacyl hydroperoxides, including benzoylperoxide, are electron deficient, compared to dialkyl peroxides.

Based on QSAR modeling, diisobutyryl peroxide is self-classified as a skin sensitizer.

Migrated from Short description of key information:

While a skin sensitization study is not required due to the corrosive nature of the registered substance, the OECD Toolbox indicates the potential for protein binding (skin sensitization) via protein nucleophilic acyloxylation.  DEREK Nexus  and TOPKAT also predict skin sensitization. Based on QSAR modeling, diisobutyryl peroxide is self-classified as a skin sensitizer.

Justification for selection of skin sensitisation endpoint:

In accordance with column 2 of REACH Annex VII, the test for skin sensitization (required in section 8.3) does not need to be conducted as the substance is classified as corrosive to the skin (see IUCLID section 7.3).  However, the OECD Toolbox indicates the potential for skin sensitization. DEREK Nexus  and TOPKAT also predict skin sensitization.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in chemico
Type of information:
(Q)SAR
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The OECD toolbox predictes that the registered substance has the potential for protein binding (skin sensitization). The registered substance is thermally and hydrolytically unstable. It is not known whether this property impacts the proposed mechanism of action or whether the Toobox takes this property into account. DEREK Nexus and TOPKAT also predict skin sensitization. In accordance with column 2 of REACH Annex VII, the test for skin sensitization (required in section 8.3) does not need to be conducted as the substance is classified as corrosive to the skin (see IUCLID section 7.3). However, based on QSAR modeling, the substance is self-classified as a skin sensitizer.
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6
Qualifier:
no guideline required
Principles of method if other than guideline:
OECD QSAR Toolbox v2.3.0.1132
GLP compliance:
no
Specific details on test material used for the study:
Not applicable
Details on the study design:
OECD QSAR Toolbox v2.3.0.1132
Key result
Remarks on result:
other: The OECD toolbox predictes that the registered substance has the potential for protein binding (skin sensitization).

The OECD toolbox predictes that the registered substance has the potential for protein binding (skin sensitization). The registered substance is thermally and hydrolytically unstable. It is not known whether this property impacts the proposed mechanism of action or whether the Toobox takes this property into account. DEREK Nexus and TOPKAT also predict skin sensitization. In accordance with column 2 of REACH Annex VII, the test for skin sensitization (required in section 8.3) does not need to be conducted as the substance is classified as corrosive to the skin (see IUCLID section 7.3). However, based on QSAR modeling, the substance is self-classified as a skin sensitizer.

Interpretation of results:
Category 1 (skin sensitising) based on GHS criteria
Conclusions:
According to the Toolbox, compounds with this similar structure react by attack of the protein nucleophile on one of the central oxygen atoms, with a carboxylate anion acting as a leaving group. The central oxygen atoms of diacyl hydroperoxides, including benzoylperoxide, are electron deficient, compared to dialkyl peroxides. DEREK Nexus and TOPKAT also predict skin sensitization. Based on this, diisobutyryl peroxide is self-classified as a skin sensitizer.
Executive summary:

OECD Toolbox indicates the potential for skin sensitization via protein nucleophilic acyloxylation. DEREK Nexus and TOPKAT also predict skin sensitization. A skin sensitization study is not available. In accordance with column 2 of REACH Annex VII, the test for skin sensitization (required in section 8.3) does not need to be conducted as the substance is classified as corrosive to the skin (see IUCLID section 7.3).

However, based on QSAR modeling, diisobutyryl peroxide is self-classified as a skin sensitizer.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (sensitising)

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Based on QSAR modeling, diisobutyryl peroxide is self-classified as a skin sensitizer, category 1.