α-chlorotoluene

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: DNA damage and/or repair

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study sufficiently described and comparable to OECD guideline 474 with a little deviation observed as the population of erythrocytes is not characterized (young/old). Therefore, this study should be considered as reliable with restrcitions, a Klimisch 2.c study.

Data source

Reference

Reference Type:

publication

Title:

In vivo mutagenicity of benzyl chloride and six structurally related analogues in the micronucleus test

Author:

Sison L.J., and Lim-Sylianco C.Y.

Year:

1990

Bibliographic source:

Acta Manilana, 38, 97-102.

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

yes

Remarks:

no report of immature erythrocyte

Principles of method if other than guideline:

The authors tested the mitagenicity of benzyl chloride in a micronucleus test in vivo accroding to the methodology developped by Schmid.

GLP compliance:

not specified

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

α-chlorotoluene

EC Number:

202-853-6

EC Name:

α-chlorotoluene

Cas Number:

100-44-7

Molecular formula:

C7H7Cl

IUPAC Name:

(chloromethyl)benzene

Details on test material:

- Name of test material (as cited in study report): benzyl chloride purchased from Aldrich chemical
- Physical state: liquid
- Storage condition of test material: dark
No further available data

Test animals

Species:

mouse

Strain:

Swiss Webster

Sex:

male/female

Administration / exposure

Route of administration:

intraperitoneal

Duration of treatment / exposure:

Two applications: 30 and 6 hours prior the preparation of the bone marrow.

Frequency of treatment:

Two applications: 30 and 6 hours prior the preparation of the bone marrow.

Post exposure period:

No post exposure period, sacrificed at the end by cervical dislocation.

Doses / concentrations

Remarks:

Doses / Concentrations:
75, 150 and 300 µmol/kg
Basis:
nominal conc.
corresponding to 1/8 LD50, 1/4 LD50 and 1/2 LD50

No. of animals per sex per dose:

Eight mice per dose level

Control animals:

yes, concurrent vehicle

Positive control(s):

N-dimethylnitrosamine
- Route of administration: intraperitoneally
- Doses / concentrations: 10 mg/kg
No further data

Examinations

Tissues and cell types examined:

The marrow fluid was extracted and spread on slides. The slides were stained in May-Gruenwald and Giemsa solution. One thousand polychromatic erythrocytes per slide were examined for the existence of micronuclei under a light microscope.

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

ambiguous

Toxicity:

not specified

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): ambiguous
In the test conditions, the authors tested the mutagenicity of benzyl chloride in vivo according to a methodology similar to the OECD guideline 474 (Mammalian Erythrocyte Micronucleus Test). They found a significant induction of micronuclei in the erythocytes of the bone marrow of treated mice. However, this increase was not estimated dose dependant and the induction rate was lower than the 3-fold threshold generally recommended. Benzyl chloride should therefore be considered as a potential mutagen but would require further testing to establish its mutagenicity. Finally these results should be interpretated as ambiguous.

Executive summary:

The authors tested the mutagenicity of benzyl chloride in vivo according to a methodology similar to the OECD guideline 474 (Mammalian Erythrocyte Micronucleus Test) on Swiss-Webster male and female mice. Eight mice per dose were injected intraperitoneally less than 8 mL/kg bw of benzyl chloride solutions freshly diluted in DMSO twice. The concentrations corresponded to 1/8 LD50, 1/4 LD50 and 1/2 LD50 previously established in a screening test. The injections of benzyl chloride solutions took place 30 and 6 hours prior the preparation of the bone marrow. At the end of the exposure period, mice were sacrificed and bone marrow fluids were collected, stained and the number of micronucleated polychromatic erythrocytes on per thousand were counted to establish cytogenetic damages. Results for the benzyl chloride were then compared with other tested substances.

In the test conditions, the authors established that benzyl chloride induced significantly micronucleated polychromatic erythrocytes compared with solvent control. However, this increase was not estimated dose dependant and the induction rate was lower than the 3-fold threshold generally recommended. Benzyl chloride should therefore be considered as a potential mutagen but would require further testing to establish its mutagenicity on somatic cells. Finally, these results should be interpretated as ambiguous.

The GLP status of this study is unknown. However, it was sufficiently described and very similar to the OECD guideline 474. Only a minor deviation was noted on the characterisation of the erythrocyte population (immature erythocytes number not reported). Therefore, this study should be considered as comparable to a guideline study with acceptable restrictions, a Klimisch 2.c study.