Silicic acid, lithium salt

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 - 23 Dec 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Groupe interministeriel des produits chimiques, France

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Silicic acid, lithium salt

EC Number:

235-730-0

EC Name:

Silicic acid, lithium salt

Cas Number:

12627-14-4

Molecular formula:

Li2O*2.8SiO2 - Li2O*6.3SiO2

IUPAC Name:

Silicic acid, lithium salt

Details on test material:

- Name of test material (as cited in study report): lithium silicate
- Physical state: white, granular
- Analytical purity: >99%
- Lot/batch No.: 009061957
- Expiration date of the lot/batch: 28 May 2010
- Storage condition of test material: room temperature
- Other:
Molar Ratio SiO2/Li2O: 4.8 (information provided in the product information sheet for Lithium polysilicate by the data owner)

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Elevage JANVIER (53940 Le Genest St Isle - France)
- Age at study initiation: 8 weeks
- Weight at study initiation: 189 - 203 g
- Fasting period before study: Food was removed at D-1 and then redistributed 4 h after test item administration
- Housing: by group of three in solid-bottomed clear polycarbonate cages with a stainless steel mesh lid; each cage contains sawdust bedding which was changed at least 2 times a week; each cage was installed in conventional air conditioned animal husbandry.
- Diet: M20-rat/mouse maintenance (made from the formulation EXTRALABO from PIETREMENT) ad libitum
- Water: ad libitum tap water from public distribution system (microbiological and chemical analyses carried out every six months by the IPL, Santé, Environnement Durables - Atlantique)
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 - 21
- Humidity (%): 28 - 68
- Air changes (per hr): approx. 15 changes per hour
- Photoperiod (hrs dark / hrs light): 12/12 (7:00 to 19:00)/(19:00-7:00)

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

DMSO

Details on oral exposure:

VEHICLE
- Amount of vehicle (if gavage): 10 mL/kg bw

MAXIMUM DOSE VOLUME APPLIED: 2000 mg/kg bw

DOSAGE PREPARATION (if unusual): In each step of the study, 2 g of the test item was weighed and 10 mL DMSO was added in a volumetric flask. The preparation was magnetically stirred during 24 hours to obtain a homogenous white suspension.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

6 exposed animals (3 animals in Step 1, 3 animals in Step 2), 3 control animals

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: clinical observations were carried out 30 min, 1 h, 3 h, 4 h post-dose and daily thereafter; body weights were determined on D0 (just before administering the test substance), D2, D7 and D14
- Necropsy of survivors performed: yes; All animals found dead during the study were immediately necropsied.
On D14, all survivors were anaesthetised with sodium pentobarbital and administration continued to fatal levels.
Necropsy examinations: oesophagus, stomach, duodenum, jejunum, ileon, caecum, colon, rectum, spleen, liver, thymus, trachea, lungs, heart, kidneys, urinary bladder, ovaries, uterus, adrenals, pancreas

Results and discussion

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

2 500 mg/kg bw

Based on:

test mat.

Remarks on result:

other: LD50 cut-off according to OECD 423

Mortality:

2 of 6 animals were found dead during the study: one animal from step 1 died at 28 hours 55 minutes post-dose and one animal from step 2 died at 21 hours post-dose.

Clinical signs:

other: The mortalities were preceded by a decrease in spontaneous activity (2/2) and in body temperature (2/2), increased lachrymation (1/2), bradypnea (2/2), tremors (1/2), piloerection (1/2) and absence of righting reflex (1/2). In the survival animals (4/6),

Gross pathology:

The macroscopical examination of the dead animals revealed a thinning of the corpus associated with red spots (2/2) and a thinning of the forestomach (1/2).
The macroscopical examination of the survival animals at the end of the study did not reveal treatment-related changes.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

CLP: not classified
DSD: not classified