Hydrogen peroxide-urea

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Data source

Reference

Reference Type:

review article or handbook

Title:

Opinion on hydrogen peroxide, in its free form or when released, in oral hygiene products and tooth whitening products

Author:

SCCP (Scientific Committee on Consumer Products)

Year:

2007

Bibliographic source:

European Commission Directorate C - Public Health and Risk assessment.

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

not specified

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 486 (Unscheduled DNA Synthesis (UDS) Test with Mammalian Liver Cells in vivo)

Test guideline 3

Qualifier:

no guideline required

Version / remarks:

DNA damage (8-OH-2'-deoxyguanosine; mutations in codon 61 of c-Ha-ras gene; epidermal hyperplasia and dermal cellularity changes

GLP compliance:

not specified

Type of assay:

other: inter alia micronucleus assays (4); unscheduled DNA synthesis (1) ; Drosophila SLRL assay (1)

Test material

Test material information

Constituent 1

Reference substance name:

Hydrogen peroxide

EC Number:

231-765-0

EC Name:

Hydrogen peroxide

Cas Number:

7722-84-1

Molecular formula:

H2O2

IUPAC Name:

hydrogen peroxide

Test material form:

liquid

Test animals

Species:

other: mousee, rat, drosophila melanogaster

Details on species / strain selection:

see attached background information

Sex:

not specified

Administration / exposure

Route of administration:

other: oral (mouse), injection (drosophila, rat (i.v. and i.p.)), topical (Sencar mouse)

Vehicle:

milk or water

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

536 mg/kg bw/day (actual dose received)

Remarks:

Oral, mouse: H2O2 in drinking water at 0, 200, 1,000, 3,000 or 6,000 ppm for 2 weeks.
Doses males: 0, 42.4, 164, 415 or 536 mg/kg bw/day;
females: 0, 48.5, 198, 485 or 774 mg/kg bw/day.

Doses / concentrations 2

Dose / conc.:

50 mg/kg bw/day (actual dose received)

Remarks:

rat: i.v. injection of 0, 25 or 50 mg/kg bw of 0.1 or 0..2% solutions

Doses / concentrations 3

Dose / conc.:

2 mg/kg bw/day (actual dose received)

Remarks:

Topical application, mouse: Hydrogen peroxide 70% was applied to the skin of 10 female Sencar mice per dose group at dose levels of 10, 100, or 200 µmol in 200 µl of ethanol (i.e. 0.2-3.2% solutions) twice weekly for 4 weeks.

Doses / concentrations 4

Dose / conc.:

3 other: 3% H2O2

Remarks:

injection into Drosophila melanogaster

Results and discussion

Test results

Test results 1

Key result

Sex:

not specified

Genotoxicity:

positive

Remarks:

The only study with positive result.

Toxicity:

not specified

Vehicle controls validity:

not specified

Negative controls validity:

not specified

Positive controls validity:

other:

Remarks on result:

other: Mouse; increased chromatid aberrations (local) following i.p. injection. Local effect; response presumed to depend on the presence or absence of RBCs.

Test results 2

Key result

Sex:

not specified

Genotoxicity:

negative

Remarks:

negative results in 8 of 9 in-vivo studies

Toxicity:

not specified

Vehicle controls validity:

not specified

Negative controls validity:

not specified

Positive controls validity:

not specified

Remarks on result:

other: species tested: rat, mouse, Drosophila

Applicant's summary and conclusion

Conclusions:

Hydrogen peroxide lacks genotoxicity in-vivo.

Executive summary:

Based on the negative results obtained in 9 in-vivo mutagenicity studies, it is concluded that hydrogen peroxide is a mutagen in-vitro but not in-vivo. In line with this, the SCCP endorsed in their opinion (2007) the conclusions of the European Chemicals Bureau (2003) which are cited below (quoted references contained in the EU RAR on Hydrogen Peroxide (2003)).

"Hydrogen peroxide is a mutagen and genotoxicant in a variety of in vitro test systems. The responses observed were modified by the presence of degrading enzymes (catalase), the extent of formation of hydroxyl radicals by Fenton reaction, and the cells repair abilities.

Hydrogen peroxide has been studied for possible in vivo genotoxicity. Studies employing modern methodologies have explored DNA repair in liver cells of rats administered hydrogen peroxide by intravenous infusion for 30 minutes (CEFIC, 1997), as well as micronucleus formation in mice in the context of a 2-week drinking water exposure (Du Pont, 1995), or after a single intraperitoneal injection (CEFIC, 1995), all with a negative outcome. Intravenous administration of hydrogen peroxide in the in vivo-in vitro unscheduled DNA synthesis study ensured that the substance had a fair chance to reach the target (liver) cells, although the duration of exposure was limited (CEFIC, 1997). In the micronucleus study by oral drinking water exposure (Du Pont, 1995), the systemic fate of hydrogen peroxide was uncertain, and there was no decrease in the ratio of polychromatic/normochromatic erythrocytes in the bone marrow. In the other micronucleus study (CEFIC, 1995), a single intraperitoneal injection of a large dose of hydrogen peroxide somehow affected the bone marrow (because the PE/NE decreased), but the absence of micronucleus formation must be viewed with caution because of the presumably very short lifetime of hydrogen peroxide. With a view to exploring target tissue in vivo genotoxicity and mutagenicity as a pre-screen for carcinogenicity, hydrogen peroxide 0.2-3.2% solutions in ethanol were applied to the skin of Sencar mice twice weekly for 4 weeks (Society for Plastic Industry, 1997). There was no indication of induced DNA damage (increased 8-OH- dG), c-Ha-ras mutations, epidermal hyperplasia and dermal cellularity changes. Thus, at low concentrations, and with a low application frequency, hydrogen peroxide did not induce local mutagenicity in this tissue model.

In conclusion, the available studies are not in support of a significant genotoxicity/mutagenicity for hydrogen peroxide under in vivo conditions. A wider database of genotoxicity and mutagenicity observations on other relevant target tissues in direct contact with hydrogen peroxide is, however, desirable. Mechanistic studies suggest that cells are adapted to repair DNA damage caused by oxidants; on the other hand there is some evidence that hydrogen peroxide may inhibit the repair of DNA lesions inflicted by other types of reactive chemicals (Churg et al., 1995, Pero et al., 1990, Hu et al., 1995).”

The conclusion is that hydrogen peroxide is a mutagen in-vitro but not in-vivo.