6-tert-butyl-m-cresol

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: other: erythrocyte micronuleus test

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: secondary literature: reproduced from SIAR 6-tert-Butyl-m-cresol, 08.08.2002 - well conducted study, carried out by Chemicals Evaluation and Research Institute, Hita Labo., (Japan) (2002), reliability 1 according the preevaluated OECD SIDS IUCLID

Data source

Reference

Reference Type:

secondary source

Title:

Unnamed

Year:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Principles of method if other than guideline:

OECD Guide-line 474 "Genetic Toxicology: Micronucleus Test"

GLP compliance:

yes

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

6-tert-butyl-m-cresol

EC Number:

201-842-3

EC Name:

6-tert-butyl-m-cresol

Cas Number:

88-60-8

Molecular formula:

C11H16O

IUPAC Name:

2-tert-butyl-5-methylphenol

Constituent 2

Reference substance name:

210-842-3

IUPAC Name:

210-842-3

Details on test material:

produced by Sumitomo Chemical, Lot No. 20213, Purity:99.0%

Test animals

Species:

mouse

Strain:

other: Crj: CD-1 (ICR) SPF

Sex:

male

Details on test animals or test system and environmental conditions:

no data

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

olive oil

Duration of treatment / exposure:

twice in the interval in 24 hours

Frequency of treatment:

twice in the interval in 24 hours, no further treatment

Post exposure period:

terminal killing: 24 hours after final application

Doses / concentrations

Remarks:

Doses / Concentrations:
31.3, 62.5, 125 mg/kg (Note1)
Basis:
nominal conc.

No. of animals per sex per dose:

No. of animals per dose: 6 (the analysis object:5)

Control animals:

not specified

Positive control(s):

Positive control: Mitomycin C (MMC) 2mg/kg in inj. water, single application

Examinations

Tissues and cell types examined:

micronucleated polychromatic erythrocytes (MNPCE), Polychromatic erythrocytes(PCE), Total erythrocytes(TE)

Details of tissue and slide preparation:

Preparation of specimens: bone marrow cells from the femur two specimens for each animal

Evaluation criteria:

Analysis:
1) Frequency of micronucleated polychromatic erythrocytes (MNPCE): MNPCE/Polychromatic erythrocytes(PCE) ratio (1000 PCE/specimen)
2) Effects to bone marrow cells PCE/Total erythrocytes(TE) ratio (500 TE/ specimen)

Statistics:

MNPCE/PCE: Binomial test with condition (Kastenbaum & Bowman) PCE/TE: t-test

Results and discussion

Test results

Sex:

male

Genotoxicity:

negative

Toxicity:

not specified

Vehicle controls validity:

not specified

Negative controls validity:

not specified

Positive controls validity:

not specified

Any other information on results incl. tables

result: negative
Dose level(mg/kg) 0 31.3 62.5 125 MMC
PCE/TE ratio(%) 45.5±5.12 57.4±5.72* 50.4±8.59 51.6±4.92 46.3±11.0
MNPCE/PCE ratio(%) 0.13±0.09 0.07±0.08 0.17±0.06 0.15±0.05 6.47±1.35**
( * P< 0.05 ** P< 0.01)

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): negative
Micronucleus test in mice is negative.

Executive summary:

method: mammalian erythrocyte micronuleus test in mice according OECD TG 474

result: micronucleus test in mice is negative

reference: chemicals Evaluation and Research Institute, Japan (20029