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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
skin sensitisation: in vivo (non-LLNA)
no data
Type of information:
experimental study
Adequacy of study:
supporting study
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: The cited statement is taken from the European Union Risk Assessment Report for hydrogen peroxide.
Principles of method if other than guideline:
Not applicable
GLP compliance:
Type of study:
not specified
other: humans
Details on test animals and environmental conditions:
Members of the general Finnish population
epicutaneous, open
other: hair dresser's chemicals
Concentration / amount:
epicutaneous, open
other: hair dresser's chemicals
Concentration / amount:
No. of animals per dose:
Not applicable
Details on study design:
Not applicable
Challenge controls:
Not applicable
Positive control substance(s):
Positive control results:
Not applicable
other: not applicable
other: not applicable
Dose level:
No. with + reactions:
Total no. in group:
Clinical observations:
Test persons were also allergic to other substances in the tested mixtures
Remarks on result:
other: Reading: other: not applicable. Group: other: not applicable. Dose level: 3%. No with. + reactions: 2.0. Total no. in groups: 158.0. Clinical observations: Test persons were also allergic to other substances in the tested mixtures.
Interpretation of results:
not sensitising
Hydrogen peroxide is not a skin sensitiser.
Executive summary:

The following text is copied from the EU Risk Assessment Report (2003), pg. 114-115:

"The skin sensitising property of nine different 3% hydrogen peroxide preparations was studied with guinea pigs using a modification of the Magnusson-Kligman procedure (Du Pont, 1953). For sensitisation five animals were given six intradermal injections of 0.1 ml 0.1% hydrogen peroxide over a 2-week period; another group of five animals received six times one drop of 3% hydrogen peroxide to the abraded skin. After a 2-week rest period the animals were challenged with a single treatment of the previous type. The skin reactions were observed at 1, 24 and 48 hours. Primary irritancy of substance on intact skin was also studied in the ten animals before the sensitisation treatment and prior to the challenge. The study does not meet modern requirements due to few animals used and inadequate reporting. However, based on summary results, all the nine hydrogen peroxide substances appeared not to sensitise (ten animals used per substance).

There is one clinical report of two cases on positive patch tests to hydrogen peroxide (Aguirre et al., 1994). The first case was a 20-year-old woman, with no previous history of atopy and allergies, who had been working as a hairdresser for 4 years, the other case was a 27-year-old housewife, with no atopy or previous allergies, who had dyed her hair herself at home every 1 to 2 months for the last 6 years. In both cases the skin reactions to 3% hydrogen peroxide were strong; the former patient was positive also for nickel sulfate and 4-aminophenol, the latter for nickel sulfate, PPD, formaldehyde, 4-aminophenol, glyceryl monothioglycolate and cocamidopropylbetaine. The authors reported that 156 other hairdressers patch tested with the hairdresser’s series of chemicals were all negative to hydrogen peroxide 3%. The Dermatological Department at the Finnish Institute of Occupational Health has since 1985 tested dermatitis patients having had exposure to hairdressing chemicals (mainly hairdressers) with a series of test substances containing 3% hydrogen peroxide in water. Computerised records were available concerning test results since 1991: 130 patients have been tested with no allergic reactions, one patient exhibited an irritant reaction. The Finnish Register of Occupational Diseases which was searched from 1975 through 1997 did not contain any cases of allergic dermatosis caused by hydrogen peroxide. The Dermatology Department of the University Central Hospital in Turku, Finland, patch tested 59 patients with 3% hydrogen peroxide during 1995-96, no positive reactions were found (Kanerva et al., 1998).

In spite of two reported cases of positive patch tests to hydrogen peroxide and the uncertainty surrounding an outdated animal study (with a negative result), and on recognition of the widespread occupational and consumer use over many decades, it may be confidently stated that the potential of hydrogen peroxide to cause skin sensitisation is extremely low and therefore do not meet the criteria for classification."

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

Although no test data are available that assess the skin sensitisation potential of the reaction mass of calcium carbonate and calcium dihydroxide and calcium peroxide, the potential of this multi-constituent substance to cause skin sensitization effects can be sufficiently assessed based on the information that is available for the read-across substances calcium dihydroxide and hydrogen peroxide.


For calcium dihydroxide, the abundance of the Ca2+ ion in the environment and the human body and the buffering capacity of the receiving organism substantiates the lack of any sensitisation potential. Likewise, for hydrogen peroxide, based on the available human and non-human information and recognizing the widespread occupational and consumer use of hydrogen peroxide over many decades, classification as a skin sensitizer is not required.

Migrated from Short description of key information:
Based on the available information, the reaction mass of calcium carbonate and calcium dihydroxide and calcium peroxide is not expected to be a skin sensitizer.

Justification for selection of skin sensitisation endpoint:
EU report available for read-across substance hydrogen peroxide.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

In accordance to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008, classification is not necessary for skin sensitisation based on the available information for read-across substances hydrogen peroxide and calcium hydroxide.