Fluorobenzene

Carcinogenicity

Administrative data

Endpoint:

carcinogenicity: dermal

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

The Tumor-promoting Action of Phenol and Related Compounds for Mouse Skin.

Author:

Boutwell, R.K.

Year:

1959

Bibliographic source:

Cancer Research 19, 413-423

Materials and methods

Principles of method if other than guideline:

Initiation/promotion assay: The TS was applied repeatedly to the skin of the backs of mice following a single application of dimethylbenzanthracene (DMBA).

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Fluorobenzene

EC Number:

207-321-7

EC Name:

Fluorobenzene

Cas Number:

462-06-6

Molecular formula:

C6H5F

IUPAC Name:

fluorobenzene

Test animals

Species:

mouse

Strain:

other: Sutter

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 2-3 months
- Housing: in screen-bottomed metal cages in air-conditioned animal rooms
- Diet: Purina Laboratory Chow ad libitum
- Water: ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 ± 3

Administration / exposure

Route of administration:

dermal

Vehicle:

other: redistilled thiophene-free benzene

Details on exposure:

About one week prior to the first application of the TS the fur was shaved from the test area of the back of the mice with electric clippers. Because of the possibility of mechanical irritation and damage to papillomas, the mice were not shaved after the experiment was started. The solutions to be tested were applied as a single drop to the mid-dorsal region of each mouse. Since the droppers delivered a known volume, the amount of solute deposited on the skin could be calculated. In each case, treatment with the promoting agent was begun 1 week after the single application of initiator and was continued twice each week until the experiment was discontinued.

Duration of treatment / exposure:

12 weeks

Frequency of treatment:

twice per week

Doses / concentrations

Dose / conc.:

1 other: drop of a 20% (w/v) solution

Remarks:

approx. 25 µl

No. of animals per sex per dose:

24 females

Examinations

Observations and examinations performed and frequency:

The mice were inspected for tumours weekly. Only typical papillomas larger than about 1 mm in diameter were counted, care being taken to exclude hyperplasias and other miscellaneous lesions. The gross identifications of both benign and malignant tumours were confirmed periodically by microscopic examination.

Results and discussion

Results of examinations

Mortality:

not specified

Description (incidence):

Four animals died during the course of the experiment.

Effect levels

Dose descriptor:

other: Tumour-promoting activity

Based on:

test mat.

Sex:

female

Remarks on result:

not determinable due to absence of adverse toxic effects

Any other information on results incl. tables

The incidence of tumours in mice treated with fluorobenzene (Initiator: 0.3% DMBA in acetone. Promotor: in benzene. Data: at 12 weeks.):

Promotor (applied twice weekly)	No. mice (survivors/original)	Average papilloma per survivor	Per cent survivors with papilloma	Per cent survivors with carcinoma*
20% fluorobenzene	20/24	0	0	0

* The incidence of carcinomas was calculated on the basis of the number of mice alive in each group on the date chosen for presentation of the data; this is not the usual definition for effectual total.

Applicant's summary and conclusion

Conclusions:

No tumour-promoting activity after a single pre-treatment with the carcinogenic dimethylbenzanthracene (DMBA).