Tetraethyl orthosilicate

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2001/01/29 - 2001/04/02

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Tetraethyl orthosilicate

EC Number:

201-083-8

EC Name:

Tetraethyl orthosilicate

Cas Number:

78-10-4

Molecular formula:

C8H20O4Si

IUPAC Name:

tetraethyl orthosilicate

Test material form:

liquid

Test animals

Species:

rat

Strain:

other: Wistar HsdCpb:WU

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelmann GmbH, Borchen, Districts of Paderborn

- Age at study initiation: ca. 8 weeks

- Weight at study initiation: 185-187g males, 159-175g females

- Housing: During the acclimatization period the animals were kept conventionally in polycarbonate cages type III (animals <180 g bw - five animals, of >180 g - max three animals per cage). The cages were changed at least three times a week. Feed racks and water bottles were not changed. During the test period the animals were kept conventionally in polycarbonate cages type III (three animals per cage). The cages were changed at least once a week. Feed racks and water bottles were not changed. The bedding consisted of low dust wood granules type BK 8/15.

- Diet: "NAFAG No.9439 Long Life W 10", ad libitum (approx. 2 hours after administration)

- Fasting: 17 hours +/- 2 before administration

- Water: tap water, ad libitum

- Acclimation period: minimum of 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): ca. 22 +/- 2

- Humidity (%): 55 +/- 5

- Air changes (per hr): ca. 15-20

- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

polyethylene glycol

Details on oral exposure:

DOSE VOLUME ADMINISTERED: 5 mL/kg bw

DOSAGE PREPARATION (if unusual): The test substance was formulated in polyethylene glycol 400 before administration. The applied formulations were well mixed by pumping the syringe several times.

Doses:

2000 mg/kg bw, single dose

No. of animals per sex per dose:

3M, 3F

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days

- Frequency of observations and weighing: appearance and behaviour were recorded several times on the day of treatment, and at least once a day thereafter. Where sign occurred, the type, period and intensity were determined individually. The body weights of the rats were recorded on day 1 before administration and then weekly. Additionally, all animals that died or were sacrificed were weighed.

- Necropsy of survivors performed: yes

- Examinations performed: clinical signs, body weight, gross pathology, other: During clinical observation all abnormal findings were registered and particular attention was paid to the following organ systems, localizations and physiological functions: appearance - fur, skin colour, edemas, eyes, lacrimation, nasal discharge, salivation; behaviour - grooming, vocalization, excitement, aggression, digging and preening movements, cannibalism; nervous system - reactivity, motility, reflexes, gait, paralysis, spasms, tremors; where accessible - respiration frequency and heart rate, pallor; posture, and gastrointestinal functions - appearance of feces, etc.

Statistics:

No statistical analysis was carried out.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no deaths.

Clinical signs:

other: There were no clinical signs.

Gross pathology:

No gross pathologic changes were observed in animals sacrificed at the end of the study period.

Other findings:

No other findings reported.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In the key acute oral study for tetraethyl orthosilicate (reliability score 1), the LD50 value of >2000 mg/kg bw in the rat was determined in a reliable study conducted according to OECD Test Guideline 423 and in compliance with GLP. There were no clinical signs or effects on body weight or gross pathology observed.