Triacetoxyethylsilane

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24.11.1999 to 02.05.2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to an appropriate OECD test guideline, and in compliance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Triacetoxyethylsilane

EC Number:

241-677-4

EC Name:

Triacetoxyethylsilane

Cas Number:

17689-77-9

Molecular formula:

C8H14O6Si

IUPAC Name:

ethylsilanetriyl triacetate

Details on test material:

- Name of test material (as cited in study report): Ethyltriacetoxysilane
- Substance type: Si-carboxylate
- Physical state: Liquid
- Stability under test conditions: No data
- Storage condition of test material: Room temperature

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, New York
- Age at study initiation: 9-12 weeks
- Weight at study initiation: Males: 238-327 g; Females: 179-224 g
- Fasting period before study: Yes, overnight
- Housing: 2-6 per cage during acclimation and individually in suspended stainless steel cages with wire mesh bottoms.
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: 7-16 days depending on the dose group.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-25
- Humidity (%): 20-66
- Air changes (per hr): No data
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 30.11.1999 To: 06.01.2000

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: No data

Doses:

300, 600, 1000, 1500 and 2000 mg/kg bw

No. of animals per sex per dose:

Five

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical signs were noted at least once daily and body weights measured pre-test and weekly throughout the study.
- Necropsy of survivors performed: yes
- Other examinations performed: food consumption recorded daily and gross macroscopic examination.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1 460 mg/kg bw

Based on:

test mat.

95% CL:

>= 1 270 - <= 1 680

Mortality:

See Table 1.

Clinical signs:

other: Signs observed in most groups on the day of dosing included red stains on the snout/extremities, lacrimation, excessive salivation and rales. Signs observed primarily in just the high dose groups (1000, 1500 and 2000 mg/kg bw) included yellow ano-genital

Gross pathology:

Findings in the stomach were distention and abnormal content, various discolorations, increased thickness of the gastric wall and, in a small number of rats, sores/depressions in the gastric mucosa. In the peritoneal/abdominal cavity, the test substance-related findings were adhesions between the stomach and other abdominal organs and the presence of abnormal peritoneal content. Overall, the findings in the stomach and in the peritoneal cavity were most prominent at 2000 mg/kg bw followed by the 1500 mg/kg bw group. Discoloration of the stomach occurred in 1/5 males and 1/5 females in the 300 mg/kg bw group. In the 1000 mg/kg bw group, increased thickness of the gastric wall occurred in 1/5 females and peritoneal adhesions occurred in 1/5 males. Other macroscopic findings occurred sporadically in the 300, 600, 1500 and 2000 mg/kg bw groups; these findings were not considered to be related to the test substance.

Other findings:

None

Any other information on results incl. tables

Table 1: Mortality results

Dose (mg/kg bw)	Mortality (# dead/total)			Time of deaths
	Male	Female	Combined
300^a	0/5	1/5^b	1/10	Day 3
600^a	0/5	0/5	0/10	N/A
1000	0/5	0/5	0/10	N/A
1500	3/5	3/5	6/10	1, 21 hours, Day 3, 5 and 8
2000	4/5	4/5	8/10	22 hours, Day 2, 3, 4, 8 and 10

a Dose levels excluded from LD₅₀ calculation.

b The cause of death of this animal was due to a dosing error.

Applicant's summary and conclusion

Interpretation of results:

Toxicity Category IV

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In an oral gavage study conducted to the now deleted OECD 401 and to GLP (reliability score 1) the LD50 for triacetoxyethylsilane was 1460 mg/kg bw in rats. Clinical signs and macroscopic findings appeared to be related to the corrosive properties of the test substance on the stomach.