Silicic acid, titanium salt

Carcinogenicity

Administrative data

Endpoint:

carcinogenicity: oral

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

07.05.198-08.05.1986

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: comparable to guidelinestudy with acceptable restrictions

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

Oral ingestion of Syloid to mice and ratsand its chronic toxicity and carcinogenicity

Author:

Y. Takizawa, F. Hirasawa, E. Noritomi, M. Aida, H. Tsunoda and S. Uesugi

Year:

1988

Bibliographic source:

Acta Medica et Biologica, Vol. 36, No. 1, 27-56

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 451 (Carcinogenicity Studies)

Principles of method if other than guideline:

Test procedure comparable to OECD-guideline, interim kill after 6 and 12 months. Four groups with 40 male and 40 female animals each. 20 animals per group were reserved for 21 months.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

112926-00-8

EC Number:

601-214-2

Cas Number:

112926-00-8

IUPAC Name:

112926-00-8

Constituent 2

Reference substance name:

silica gel, precipitated, cryst.-free

IUPAC Name:

silica gel, precipitated, cryst.-free

Details on test material:

- Name of test material (as cited in study report): Syloid 244
- Physical state: fine withe silica powder
- Lot/batch No.: JC-2108
- Expiration date of the lot/batch:
- Other: produced by Fuji Davidson Chemical Ltd.
- Composition of test material, percentage of components: SiO2 x H2O

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Funabashifarm Animal Co. Ltd. Japan
- Age at study initiation: 3 weeks
- Weight at study initiation: male: 117-150 g, female: 92-126 g
- Housing: wire-mesh cages; 2 animals/cage
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 2 weeks


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 +/- 1
- Humidity (%): 50 +/- 10
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 14 hours artificial fluorescent light

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

103 weeks

Frequency of treatment:

daily

Post exposure period:

no data

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 1.25, 2.5 and 5 %
Basis:
nominal in diet

No. of animals per sex per dose:

10; 20 animals for the 21 months timepoint

Control animals:

yes, plain diet

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

Water consumption and compound intake (if drinking water study):

no effects observed

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Clinical biochemistry findings:

effects observed, treatment-related

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not specified

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

effects observed, treatment-related

Effect levels

Dose descriptor:

NOAEL

Remarks on result:

not determinable

Remarks:

no NOAEL identified

Any other information on results incl. tables

No significant variations in survival rates were observed in males, while the female survival rates were decreased but not statistically significant different from the control group. In body weight, food intake behaviour or in hematology and clinical chemistry parameters no relevant changes were seen. Lower liver weights were noted from 12 to 24 months in the 2.5 and 5 % female dose group. In histopathological examination the tumor incidence was the greatest in testes, mammary gland (incidence in the controls higher than in the treatment groups) and prepuce (males) and mammary gland and clitoris (incidence in the controls higher than in the treatment groups) in females. (see also IARC 1997)

In relation to the low -if any- effects to be expected, the test design cannot be satisfactory with respect to biostatistics: The group sizes are too low to discriminate small effects.