Disodium metasilicate

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study performed according to basic scientific principles, study report provides only summary of data, with no/very few tables with data from individual animals. There were discrepancies between the study report and the abstract (Ito, 1986).

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Safety of anticorrosives in building water-pipe methal inhibitors sodium polyphosphate and sodium metasilicate.

Author:

Ito, R. et al.

Year:

1986

Bibliographic source:

Toxicol. Lett. 31 (Suppl. P1-28), 44

Reference 2

Reference Type:

publication

Title:

Safety of the metal scavengers sodium metasilicate and sodium polyphosphate.

Author:

Saiwai, K. et al.

Year:

1980

Bibliographic source:

Internal Report Toho University

Reference 3

Reference Type:

review article or handbook

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Principles of method if other than guideline:

Standard acute oral toxicity

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Disodium metasilicate

EC Number:

229-912-9

EC Name:

Disodium metasilicate

Cas Number:

6834-92-0

Molecular formula:

H2O3Si.2Na Soluble Silicates Category

IUPAC Name:

disodium oxosilanediolate

Details on test material:

SOURCE: Not reported
PURITY: Not reported
IMPURITY/ADDITIVE/ETC.: Not reported
ANY OTHER INFORMATION: Sodium metasilicate was administered as a 10% solution.

Test animals

Species:

mouse

Strain:

other: T23-48:ddy

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ORGANISMS: 
- Source: Sankyo Laboratory Service 
- Age: 4 weeks

Administration / exposure

Route of administration:

oral: unspecified

Vehicle:

not specified

Details on oral exposure:

- Volume administered or concentration: 0.05-0.19 ml/10g for males, 0.05-0.14 ml/10g for females

Doses:

500-1920.8 mg/kg (males), 500-1372 mg/kg (females)

Control animals:

not specified

Details on study design:

- Post dose observation period: seven days

EXAMINATIONS: mortality, clinical symptoms, histopathology

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD50

Effect level:

770 - 820 mg/kg bw

Effect levels 2

Sex:

female

Dose descriptor:

LD50

Effect level:

661.5 - 896.3 mg/kg bw

Effect levels 3

Sex:

male

Dose descriptor:

LD50

Effect level:

666.7 - 1 008.6 mg/kg bw

Remarks on result:

other: 66.7-1087.6 mg/kg is reported in Ito, 1986

Any other information on results incl. tables

MORTALITY: 
- Time of death: 4 hrs - 5 days

CLINICAL SIGNS:

2 minutes after administration males and females became lethargic and had a hunched posture. Tear flow increased with dose level. Surviving animals recovered within 2-4 days. The animals that died were lethargic, did
not react to external stimuli, had hanging eyelids, paralysis of hind legs, clonicity and tonic cramps, followed by cyanosis and respiratory paralysis.

NECROPSY FINDINGS: 

the following symptoms increased with increasing dose: localised bleeding in the mucous membranes of the "glandular stomach", duodenum, mucous membranes of the central part of the "small gut", capillary dilation,
rarefaction of the stomach lining, clear liver lobules, faded colour of the liver rim, redness of the gall. Animals
dosed 1372 mg/kg and above had bleeding and inflammation extending from the "glandular stomach"to the central part of
the "small gut". In surviving animals the liver lobules looked slightly clearer and the spleen showed slight rubefaction, compared to control group animals.

POTENTIAL TARGET ORGANS: stomach, liver, gut.