Silicic acid, sodium salt

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Well-documented study, but test substance not clearly identified and background exposure through diet not stated.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Renal damage associated with silicon compounds in dogs.

Author:

Newberne, P. M. and Wilson, R. B.

Year:

1970

Bibliographic source:

Proc. Nat. Aca. Sc. 65(4), 872-875.

Reference 2

Reference Type:

review article or handbook

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Silicic acid, sodium salt

EC Number:

215-687-4

EC Name:

Silicic acid, sodium salt

Cas Number:

1344-09-8

Molecular formula:

Na2O x (SiO2)n with Molar Ratio (MR) (SiO2/Na2O): 1.5 – 4

IUPAC Name:

sodium hydroxy(oxo)silanolate

Details on test material:

SOURCE: Not reported
PURITY: Not reported
IMPURITY/ADDITIVE/ETC.: Not reported
ANY OTHER INFORMATION: Molar ratio not reported

Test animals

Species:

rat

Strain:

other: Charles River Cesarean-Derived (CD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ORGANISMS
- Weight at study initiation:  80-100 g

Administration / exposure

Route of administration:

oral: feed

Vehicle:

other: feed

Duration of treatment / exposure:

4 weeks

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
2400 mg/kg bw/d
Basis:
other: nominal conc.

No. of animals per sex per dose:

15

Control animals:

yes

Examinations

Observations and examinations performed and frequency:

CLINICAL OBSERVATIONS AND FREQUENCY: 
- Clinical signs: registered daily
- Mortality: registered daily
- Body weight: registered weekly
- Food consumption: registered with unknown frequency
- Haematology: Total WBC count, differential WBC count, packed cell volume, prothrombine time and serum hemoglobin was registered weekly. 
- Urinalysis: Urinary specific gravity protein concentration, glucose concentration and urea nitrogen was registered weekly.

Sacrifice and pathology:

ORGANS EXAMINED AT NECROPSY (MACROSCOPIC AND MICROSCOPIC): 
- Macroscopic: the weight of not specified organs was registered.
- Microscopic: A set of tissues was preserved in formalin for histopathological examination. There are no further details.

Results and discussion

Effect levels

Dose descriptor:

NOAEL

Effect level:

2 400 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: polydipsia, polyuria and soft stools

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

TOXIC RESPONSE/EFFECTS BY DOSE LEVEL: 
- Mortality and time to death: None
- Clinical signs: Polydipsia, polyuria and soft stools was observed in a few animals (not quantified)
- Body weight gain: No effects
- Food/water consumption: No effects
- Clinical chemistry: No effects
- Haematology: No effects
- Urinalysis: No effects
- Organ weights: No effects
- Gross pathology: No effects
- Histopathology: No effects