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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Additional information on environmental fate and behaviour

Administrative data

additional information on environmental fate and behaviour
Type of information:
other: Internal Memo of measured Data
Adequacy of study:
supporting study
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Internal Akzo Nobel memo / presentation on the stability of the test substance. Non of the requirements for a valid stand alone scientific study have been met as data was generated in a research environment whilst gathering stability data on the substance concerned. It is however valuable supplimentry information regarding the stability of Diisobutryl peroxide when used in conjunction with the other stability data obtained.

Data source

Reference Type:
other company data

Materials and methods

Test guideline
no guideline followed
GLP compliance:
Type of study / information:
Summary of stability experiments carried out in the research and development laboratory in Deventer the Netherlands.

Test material

Constituent 1
Chemical structure
Reference substance name:
Bisisobutyryl peroxide
EC Number:
EC Name:
Bisisobutyryl peroxide
Cas Number:
Molecular formula:
2-methylpropanoyl 2-methylpropaneperoxoate
Constituent 2
Reference substance name:
Diisobutrylperoxide in isododecane
Diisobutrylperoxide in isododecane
Test material form:
other: Liquid mixed with 70 % Isododecane for stability
Details on test material:
Test material was 30 % Diisobutryl peroxide in 70 % isododecane. Diisobutryl peroxide degrades very rapidly isododecane is therefore added to aid
stability .

Results and discussion

Any other information on results incl. tables


Results are displayed graphically and have been attached below. Measurments show a rapid increase in

the concentration of isobutryic acid a rapid decrease in the concentration of diisobutryl peroxide with time. Degradation products Acetone,Propene and Isopropanoic acid are formed in much lower amounts. It should be noted that the low level degradation products are volatile and rapidy leave the water phase which could have lead to a greater error in these measurements.

Applicant's summary and conclusion

In conclusion diisobutryic acid is instable in water and hydrolizes rapidly (completely in 60 minutes) to multiple degradation products some of
which are volatile and would therefore leave the water phase. This should be taken into consideration during the environmental risk assessment and may be used to support data measured in the ecotoxicity and hydrolysis endpoints.
Executive summary:

ConclusionsDiisobutryl peroxide decomposes completely in water after 60 minutes at 27°C .The decomposition products observed are:Isobutyricacid (IBA),Isopropanol,propene and acetone. The main decomposition/hydrolysis product found is Isobutyric acid. Propene is also likely to be one of the decomposition product s but the exact amount can not be determined as it is a highly volatile compound.