α,α,α-trichlorotoluene

Repeated dose toxicity: dermal

Administrative data

Endpoint:

sub-chronic toxicity: dermal

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study fulfils generally well accepted scientific criteria and is sufficiently described. Klimisch 2e

Data source

Reference

Reference Type:

publication

Title:

Carcinogenicity of benzyl chloride, benzal chloride, benzotrichloride and benzoyl chloride in mice by skin application

Author:

Fukuda K., Matsushita H., Sakabe H. and Takemoto K.

Year:

1981

Bibliographic source:

Gann, 72: 655-664

Materials and methods

Principles of method if other than guideline:

- The backs of the ICR mice were clipped free of hair before treatment and clipping was repeated when necessary.
- Benzene solutions of the test material were prepared just prior to treatment. The dorsal skin application was done with a micropipette.
- Three experiments were performed with different exposure durations and concentrations. Experiment I was done on 14 week old mice, while experiment II used 3 week old weanling mice and experiment III 7 week old mice
- When moribund or at the indicated time mice were ether killed and completely necropsied. After gross pathological inspection the organs and
tumors were exised , fixed, paraffin embedded, 5 μm sections made and stained appropiately for histological evaluation.

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

α,α,α-trichlorotoluene

EC Number:

202-634-5

EC Name:

α,α,α-trichlorotoluene

Cas Number:

98-07-7

Molecular formula:

C7H5Cl3

IUPAC Name:

α,α,α-trichlorotoluene

Constituent 2

Reference substance name:

trichloromethylbenzene

IUPAC Name:

trichloromethylbenzene

Details on test material:

reagent grade commercial material from Tokyo Kasei Co. Ltd., Tokyo
No further information

Test animals

Species:

mouse

Strain:

ICR

Sex:

female

Administration / exposure

Type of coverage:

other: No, painted

Vehicle:

other: benzene

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

Experiment I: 30 weeks
Experiment II: 41 weeks
Experiment III: 50 weeks (terminated after 13.3 months.)

Frequency of treatment:

Experiment I: 2/w 3 w, 1/w 27 w
Experiment II: 3/w 4 w, 2/w 37 w
Experiment III: 2/w 50 w

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
12.5, 25 μl/animal/painting (Experiment I)
Basis:
nominal per unit area

Doses / concentrations 2

Remarks:

Doses / Concentrations:
5, 10 μl/animal/painting (Experiment II)
Basis:
nominal per unit area

Doses / concentrations 3

Remarks:

Doses / Concentrations:
2.3 μl/animal/painting (Experiment III)
Basis:
nominal per unit area

No. of animals per sex per dose:

Experiment I: 20, 19, 22 animals were exposed in the control, 12.5 and 25 μl/animal/painting respectively
Experiment II: 10 animals per dose
Experiment III: 20 animals per dose

Control animals:

yes, concurrent vehicle

Results and discussion

Effect levels

1

Dose descriptor:

NOAEL

Basis for effect level:

other: None of the effects reported allowed to derive a NOAEL

Remarks on result:

not determinable

Remarks:

no NOAEL identified

2

Dose descriptor:

NOEL

Basis for effect level:

other: None of the effects reported allowed to derive a NOEL

Remarks on result:

not measured/tested

Remarks:

Effect level not specified (migrated information)

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

- During a few minutes after dermal painting of mice a marked irritation of the eyes, the skin and the respiratory system as well as elevated motor activities were seen.

- At the painted area first erythema and swelling were noted later alopecia, induration, marked keratinization, ulcers and/or necrosis of the epidermis were observed. The lesions were rather severe.

Experiment I:

- Mortality at the termination of the experiment was 0, 10 and 46% in the control, low- and high-dose groups, respectively. The high dose corresponded to a total of approximately 1165 mg (average dose rate of 5.4 mg/day) and the low dose to 582.4 mg (average dose rate of 2.7 mg/day).

- The number of mice with tumours was 0/20, 17/19, and 21/22 in the control, low-dose, and high-dose groups, respectively.

Experiment II:

The high dose represented a total of 1206 mg and the low dose 603 mg (4.3 and 2.1 mg/day, respectively). Mortality at termination was 0, 60, and 80% for the control, low-dose, and high-dose groups, respectively. The number of mice with tumours was 0/10, 10/10, and 8/9 in the control, lowdose, and high-dose groups, respectively.

Experiment III:

The total dose was approximately 315 mg (0.9 mg/day). Mortality at termination was 20% in the controls compared with 35% in the treated group. In the control group, 2/20 mice had lung adenomas while in the treated group, 13/19 had skin carcinoma and 11/19 had lung adenoma/carcinoma. Nineteen other tumors, attributed to licking, were observed in the lips, tongue, esophagus, forestomach and glandular stomach of the treated mice.

Systemic effects:

Leukemogenic and pulmonary tumourigenic activity was observed

Applicant's summary and conclusion

Conclusions:

The authors tested the repeated dose toxicity of benzotrichloride by painting the clipped back of ICR female mice in three different sets of sub-chronic experiment. The authors observed irritation of the eyes, the skin and the respiratory tract as well as an increase in motor activities. Erythema and swelling were noted, later-on alopecia, induration, marked keratinization, ulceration and/or epidermal necrosis and especially an greater induction of skin tumors were observed at treated skin. Neither a NOEL nor a NOAEL could be derived since the experiment was not adequately designed.

Executive summary:

The authors tested the repeated dose toxicity of benzotrichloride (CAS n° 98 -07 -7) by painting the clipped back of ICR female mice in three different sets of sub-chronic experiments.

In an first experiment (I), mice received 12.5 or 25 μl/animal/painting, twice a week during 3 weeks, and then once a week for 27 weeks. In a second experiment (II), mice received 5 or 10 μl/animal/painting, three times a week during 4 weeks, and then twice a week for 37 weeks. In a third experiment (III), mice received 2.3 μl/animal/painting twice a week during 50 weeks.

The high dose corresponded in experiment (I) to a total of approximately 1165 mg (average dose rate of 5.4 mg/day) and the low dose to 582.4 mg (average dose rate of 2.7 mg/day). For the experiment (II), the high dose represented a total of 1206 mg and the low dose 603 mg (4.3 and 2.1 mg/day, respectively). And then for the experiment (III), the total dose was approximately 315 mg (0.9 mg/day). Immediate reactions, mortality and pathological signs were monitored and tumours were diagnosed and counted in all animals at their death or at the end of the exposure period.

Hence, during a few minutes after dermal painting of mice a marked irritation of the eyes, the skin and the respiratory system as well as elevated motor activities were seen. Besides, at the painted area first erythema and swelling were noted later alopecia, induration, marked keratinization, ulcers and/or necrosis of the epidermis were observed. The lesions were rather severe.

Thus, in the experiment (I), mortality at the termination of the experiment was 0, 10 and 46% in the control, low- and high-dose groups, respectively. The number of mice with tumours was 0/20, 17/19, and 21/22 in the control, low-dose, and high-dose groups, respectively.

In the experiment (II), mortality at termination was 0, 60, and 80% for the control, low-dose, and high-dose groups, respectively. The number of mice with tumours was 0/10, 10/10, and 8/9 in the control, lowdose, and high-dose groups, respectively.

in the experiment (III), mortality at termination was 20% in the controls compared with 35% in the treated group. In the control group, 2/20 mice had lung adenomas while in the treated group, 13/19 had skin carcinoma and 11/19 had lung adenoma/carcinoma. Nineteen other tumors, attributed to licking, were observed in the lips, tongue, esophagus, forestomach and glandular stomach of the treated mice.

Altogether, these elements prove that benzotrichloride induced local and systemic effects (leukemogenic and pulmonary) on female mice exposed dermally, mainly tumerogenic activity.

None of the effects reported allowed to derive a NOEL or a NOAEL. They only show obvious evidence of the carcinogenic potential of benzotrichloride. The GLP status of the study is unknwon but the study is sufficiently described even if further investigation on the clinical signs would have been preferable. Besides, due to the small of the group, no statistical evaluation was performed. The experiment was nethertheless based on generally well accepted scientific principles. Therefore, this study should be considered as reliable with restrictions, a Klimisch 2.e study.