Registration Dossier

Toxicological information

Acute Toxicity: oral

Currently viewing:

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:
OECD Guideline 401 (Acute Oral Toxicity)
GLP compliance:
yes
Test type:
standard acute method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
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 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:
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 stains, black/brown ano-genital stains, decreased activity and/or lethargy, hunched appearance, laboured breathing and red urine or red stains beneath animals' cages. Additional signs observed in all groups on the day after dosing included decreased food consumption and decreased faecal volume or no stool. Most animals in the 300 and 600 mg/kg bw groups were free of signs of toxicity by Day 3 or 8, respectively; most surviving animals in groups 1000, 1500 and 2000 mg/kg bw were free of signs of toxicity by Day 13.
Body weight:
Most survivors gained weight at both 7 and 14 days (Days 8 and 15) after dosing. A few survivors lost weight by Day 8, but gained weight by Day 15, and a few gained weight by Day 8, but lost weight or had no weight change by Day 15.
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

300a

0/5

1/5b

1/10 

 Day 3

600a

 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.