Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vivo

Description of key information

in-vitro: negative in Ames Test with Salmonella strains TA98, TA100, TA1535 and TA1537 (with and without microsomal activation) (Ciba-Geigy 1977) in-vivo: negative in Chromosome Aberration Test in Chinese Hamster upon gavage application (Ciba-Geigy 1981) in-vivo: negative in Micronucleus Assay in Chinese Hamster upon gavage application (Ciba-Geigy 1976) in-vivo: negative in Dominant Lethal Study in mice (Ciba-Geigy 1977)

Link to relevant study records

Reference

Endpoint:

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

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline, without GLP (acceptable with restrictions)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 475 (Mammalian Bone Marrow Chromosome Aberration Test)

Deviations:

yes

Remarks:

limited documentation (no evaluation criteria reported)

GLP compliance:

no

Type of assay:

chromosome aberration assay

Species:

hamster, Chinese

Strain:

other: Cricetulus griseus

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: male 27-38 g, female 23-30 g
- Diet (e.g. ad libitum): Standard diet, NAFAG No.924
- Water (e.g. ad libitum): tap water

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23±1
- Humidity (%): 55±5
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: CMC (carboxymethyl cellulose)
- Concentration of test material in vehicle: 2 %
- Amount of vehicle (if gavage or dermal): 20 ml/kg bw

Duration of treatment / exposure:

2 days

Frequency of treatment:

once daily

Remarks:

Doses / Concentrations:
500, 1000 and 2000 mg/kg bw
Basis:
actual ingested

No. of animals per sex per dose:

4

Control animals:

yes, concurrent vehicle

Positive control(s):

cyclophosphamide
- Doses / concentrations: 64 mg/kg bw

Tissues and cell types examined:

bone marrow

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION:
Based on the Lab results (PH 2.634, dated March 11, 1975), the oral LD was found to be >6000 mg/kg bw in Chinese hamster of either sex.

TREATMENT AND SAMPLING TIMES:
The treated groups consisted of four female and four male animals each. The control groups consisted of six female and six male animals each. The substance was administered orally once daily on 2 consecutive days. The animals were injected intraperitoneally with 10 mg colcemide/kg 2 h after the second dose and sacrificed 4 h later.

METHOD OF ANALYSIS:
Four animals (two females and two males) from each group treated with the various doses of the test article and from the negative and from the positive control group each were analysed by reference to the following criteria:
- Chromatid-type aberrations
- Chromosome-type aberrations
- Chromatid gaps
- Chromosome pulverizations
100 metaphases were analysed per animal.

Evaluation criteria:

no data

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RESULTS OF DEFINITIVE STUDY
- In the low-dose group one metaphase (out of 400 metaphases) was found showing a chromatid-type aberration in the form of a break. The chromosome displays from animals of the intermediate-dose, of the high-dose and of the control group showed no aberrations.
- In contrast to the test substance, cyclophosphamide, 64 mg/kg bw used as positive control caused an increase in all types of aberrations (chromatid-type aberrations 22.0%; chromosome-type aberrations 0.25%). The difference is highly significant (p<0.05).

The Effect of TK10044 and Cyclophosphamide on Bone Marrow Cells of Chinese Hamster

Parameters	Control	Cyclophosphamide	Irganoc 1076 (mg/kg bw)
	2% CMC	64 mg/kg bw	500	1000	2000
Percent of metaphases with specific aberrations	0	22	0	0	0
Chromatid-type aberrations (mean)	0	22	0.25	0	0
Chromosome-type aberrations (mean)	0	0.25	0	0	0
Chromatid gaps (mean)	2.25	17.5	2.5	2.75	2.25

Conclusions:

Interpretation of results (migrated information): negative
It can be concluded from the results that the test substance exerted no mutagenic action in the Chinese hamster under the experimental conditions.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vivo:

Genetic toxicity in-vitro:

An Ames test using Salmonella typhimurium TA98, TA100, TA1535 and TA1537 at test concentrations ranging from 5-250 µg/plate with and without metabolic activation was performed similar to guideline OECD 471 (Ciba-Geigy 1977). The test substance is poorly soluble and precipitated in the agar. No evidence of the induction of mutations by the test substance or by the metabolites of the substance formed as a result of microsomal activation was detectable in the strains of S. typhimurium used in these experiments.

Genetic toxicity in-vivo:

In the key study (CIBA-GEIGY 1981) performed similar to the OECD Guideline 475 (Mammalian Bone Marrow Chromosome Aberration Test), treatment consisted of one daily dose of the test substance on each of 2 consecutive days by oral gavage at dose levels of 500, 1000 and 2000 mg/kg bw. The animals were injected ip with colcemide (10 mg/kg bw) 2 h after the second dose and sacrificed 4 h later. From the bone marrow, chromosome preparations were made to evaluate any mutagenic effect on the somatic cells. In the low-dose group one metaphase (out of 400 metaphases) was found showing a chromatid-type aberration in the form of a break. The chromosome displays from animals of the intermediate-dose, of the high-dose and of the control group showed no aberrations. In contrast, cyclophosphamide, 64 mg/kg bw used as positive control caused an increase in all types of aberrations (chromatid-type aberrations 22.0%; chromosome-type aberrations 0.25%). Thus it was concluded that the test substance exerted no mutagenic action in the Chinese hamster under the experimental conditions.

The result was supported by a micronucleus assay (CIBA-GEIGY 1976) where the test substance was administered by gavage. Treatment consisted of one daily application on 2 consecutive days. The animals were sacrificed 24 h after the second application and the bone marrow smears were made to evaluate any mutagenic effect on somatic interphase cells. In all dosage groups the percentage of cells displaying anomalies of nuclei did not differ significantly from the negative control. By contrast, the positive control (cyclophosphamide, 128 mg/kg bw) yielded a marked increase of the percentage of cells with anomalies.

The results were further supported by a dominant lethal assay (CIBA-GEIGY 1975) where the compound was administered orally in single doses of 1000 and 3000 mg/kg bw to male albino mice which were then mated to untreated females over a period of six weeks. Any cytotoxic or mutagenic effects on the male germinal cells as expressed by the loss of pre-implantation zygotes as well as by the rate of deaths of post-implantation stages of embryonic development were evaluated. The results exhibited no evidence of dominant lethal effects. The numbers of implantations and embryonic deaths were comparable for all groups.

Based on all the data, it can be concluded that the substance is not mutagenic in-vivo.

Justification for selection of genetic toxicity endpoint
The most recent in vivo study was selected.

Justification for classification or non-classification

Dangerous Substance Directive (67/548/EEC)

The available studies are considered reliable and suitable for classification purposes under 67/548/EEC. As a result the substance is not considered to be classified for genotoxicity under Directive 67/548/EEC, as amended for the 28th time in Directive 2001/59/EC.

Classification, Labelling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. As a result the substance is not considered to be classified for genotoxicity under Regulation (EC) No. 1272/2008.