α,α,α,2-tetrachlorotoluene

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

GLP compliance:

yes

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

α,α,α,2-tetrachlorotoluene

EC Number:

218-377-7

EC Name:

α,α,α,2-tetrachlorotoluene

Cas Number:

2136-89-2

Molecular formula:

C7H4Cl4

IUPAC Name:

1-chloro-2-(trichloromethyl)benzene

Details on test material:

Purity: 98.6 %

Test animals

Species:

mouse

Strain:

NMRI

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: BRL Tierfarm Fuellinsdorf CH
- Age at study initiation: 10 weeks
- Weight at study initiation: 30g
- Assigned to test groups randomly: yes
- Fasting period before study: yes 18 hours
- Housing: singly in Makrolon type 1 with granulated softwood bedding
- Diet (e.g. ad libitum): Altromin standard diet, ad libitum
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21+-3
- Humidity (%): 30-70%
- Air changes (per hr): not given
- Photoperiod (hrs dark / hrs light): 12 hours 6am-6pm

IN-LIFE DATES: From: 17-09-1990 To: 05-11-1990

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

Polyethylene glycol 400

Details on exposure:

10 mL/kg bw

Duration of treatment / exposure:

single dose administered on day 1

Frequency of treatment:

single dose

Post exposure period:

24, 48 and 72 hours

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

100 mg/kg bw (total dose)

Doses / concentrations 2

Dose / conc.:

333 mg/kg bw (total dose)

Doses / concentrations 3

Dose / conc.:

1 000 mg/kg bw (total dose)

No. of animals per sex per dose:

5 (five)

Control animals:

yes, concurrent vehicle

Positive control(s):

40 mg/kg bw cyclophosphamid

Examinations

Tissues and cell types examined:

bone marrow smears; 1000 polychromatic erythrocytes

Details of tissue and slide preparation:

bone marrow extracted with fetal calf serum; centrifuged and the pellet resuspended. small drop of resuspended cell pellet spread on slide and air dried. Stained with May-Grunwald/Giesma.

Evaluation criteria:

A test article is classified as mutagenic if it induces either a statistically significant dose related increase in the number of micronucleated polychromatic erythrocytes or a reproducible statistically significant positive response for at least one of the test points.
A test article producing neither a statistically significant dose-related increase in the number of micronucleated polychromatic erythrocytes nor a reproducible statistically significant positive response at anyone of the test points is considered non-mutagenic in this system.

Statistics:

non-parametric Mann-Whitney test

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

positive

Toxicity:

yes

Vehicle controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

test group	dose mg/kg bw	sampling time (h)	PCE with MNE	range	PCE/NCE
vehicle	0	24	0.06%	0 -2	1000/845
test substance	100	24	0.09%	0 -4	1000/904
test substance	333	24	0.16%	0 -6	1000/898
test substance	1000	24	0.21% *	0 -4	1000/936
positive control	40	24	1.08% *	7 -20	1000/972
vehicle	0	48	0.06%	0 -2	1000/898
test substance	1000	48	0.39% *	0 -9	1000/1016
vehicle	0	72	0.1%	0 -3	1000/682
test substance	1000	72	0.475%	1 -8	1000/1261

* = P<0.05% by the Mann Whitney non parametric test

Applicant's summary and conclusion

Conclusions:

Based upon the findungs of this study o-chlorobenzotrichloride is considered to be mutagenic in the micronucleus assay.

Executive summary:

In comparison to the negative control a dose dependent increase in the frequenccy of micronuclei 24 hours after the application of the test item was observed. A statistically significant increase in the micronucleated polychromatic erythrocyte frequencies was observed for the highest dose group.