Registration Dossier

Administrative data

Endpoint:
carcinogenicity: oral
Type of information:
experimental study
Adequacy of study:
other information
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: 3b: Significant methodological deficiences. This study was carried out a long time ago so there was a lack of information concerning the test conditions.

Data source

Reference
Reference Type:
publication
Title:
Tolerance of diphenylthiourea in long-term feeding tests in rats.
Author:
Mohr H.J., Nothdurft H.
Year:
1967
Bibliographic source:
Int Archiv für Gewerbepathologie und Gewerbehygiene, 1967; 23: 168-174.

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Testing for carcinogenic effect after 2 years' feeding. Lifespans of animals and times to appearance of individual tumours are observed.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
no data

Test animals

Species:
rat
Strain:
not specified
Sex:
male/female
Details on test animals and environmental conditions:
No data

Administration / exposure

Route of administration:
oral: feed
Details on exposure:
by feeding for life-time with a diet containing 1000 ppm of test substance.
Duration of treatment / exposure:
2 years
Frequency of treatment:
daily
Doses / concentrations
Remarks:
Doses / Concentrations:
1000 ppm
Basis:
nominal in diet
No. of animals per sex per dose:
test group: 79 females + 81 males
control group: 101 females + 99 males
Control animals:
yes
Positive control:
no

Examinations

Observations and examinations performed and frequency:
- Clinical signs were observed: malign and benign tumours
- Mortality: yes
Statistics:
No data

Results and discussion

Results of examinations

Clinical signs:
not specified
Mortality:
not specified
Body weight and weight changes:
not specified
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not specified
Haematological findings:
not specified
Clinical biochemistry findings:
not specified
Urinalysis findings:
not specified
Behaviour (functional findings):
not specified
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
not specified
Details on results:
Result (carcinogenicity): negative. No significant results were observed in this study.

AMONG THE FEMALES:
- In the treated group:
. 1 mammary fibroadenoma appeared between the 16th and 18th months of the trial,
. 2 mammary fibroadenomas and 1 spindle-cell sarcoma between the 19th and 21st months.
Between the 16th and 18th months, the half of the animals was dead and at the end of the trial only 1 animal was still living.

- In the control group:
. 1 mammary fibroadenoma and 1 fibrosarcoma appeared between the 19th and 21st months,
. 1 intraperitoneal sarcoma between the 22nd and 24th months,
. 3 mammary fibroadenomas and 1 uterine adenocarcinoma between the 25th and 27th months,
. 3 mammary fibroadenomas between the 28th and 30th months,
. 1 mammary fibroadenoma and 1 uterine sarcoma from the 31st month of the trial.
As in the treated group, between the 16th and 18th months, the half of the animals was dead and at the end of the trial only 1 animal was still living.

AMONG THE MALES:
- In the treated group:
. 1 bladder wall adenocarcinoma was observed between the 13th and 15th months,
. 1 lipoma between the 16th and 18th months,
. and 1 haemangio-endothelioma from the 31st month of the trial. Between the 13th and 15th months, the half of the animals was dead and no surviving animals was found at the end of the trial.

- In the control group:
. 1 lymphosarcoma was detected between the 13th and 15th months,
. and 1 fibrosarcoma between the 28th and 30th months of the trial. No surviving animals was found too at the end of the trial.
=> No rise in specific tumours and so no carcinogenic effects was observed in treated animals compared to controls.

Effect levels

Dose descriptor:
NOAEL
Effect level:
> 1 000 ppm
Remarks on result:
other: Effect type: carcinogenicity (migrated information)

Applicant's summary and conclusion