Reaction mass of tetrahydroxysilane and choline chloride and calcium chloride and water

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

1987

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Tetrahydroxysilane

EC Number:

233-477-0

EC Name:

Tetrahydroxysilane

Cas Number:

10193-36-9

Molecular formula:

H4O4Si

IUPAC Name:

orthosilicic acid

Constituent 2

Reference substance name:

Choline chloride

EC Number:

200-655-4

EC Name:

Choline chloride

Cas Number:

67-48-1

Molecular formula:

C5H14NO.Cl

IUPAC Name:

2-hydroxy-N,N,N-trimethylethanaminium chloride

Test material form:

liquid

Remarks:

light yellow liquid

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Rat, Wistar Crl:(WI) BR (outbred, SPF-Quality), Charles River, Germany;
Age at start of treatment : Approx 6 or 7 weeks
Body weight at start of treatment : within +- 20% of the sex mean
Number of animals per group : 5 males and 5 females

Air-conditioned room with approx 15 air changes per hour and the environment controlled with optimal conditions considered as being a temperature of 21°C and a relative humidity of 50%. Fluctuations from these optimal conditions were noted, but were considered not to have affected the study integrity. Lighting was 12 hours artificial fluorescent light and 12 hours dark per day.

Group housing of 5 animals per sex per cage in labelled polycarbonate cages containing purified sawdust as bedding material. certificates of analysis were examined and then retained in the NOTOX archives. Acclimatisation period was at least 5 days before start of the treatment under laboratory conditions.

Administration / exposure

Route of administration:

oral: gavage

Doses:

Group 1 : 5000 mg/kg bw
Group 2 : 5700 mg/kg bw
Group 3 : 6500 mg/kg bw

No. of animals per sex per dose:

5 males and 5 females per dose

Results and discussion

Effect levels

Effect levels 1

Sex:

male

Dose descriptor:

LD50

Effect level:

5 838 mg/kg bw

Based on:

test mat.

Remarks on result:

other: no conficence limits could be determined due to the mortality distribution

Effect levels 2

Sex:

female

Dose descriptor:

LD50

Effect level:

5 421 mg/kg bw

Based on:

test mat.

Remarks on result:

other: no conficence limits could be determined due to the mortality distribution

Effect levels 3

Sex:

male/female

Dose descriptor:

LD50

Effect level:

5 592 mg/kg bw

Based on:

test mat.

95% CL:

4 337 - 6 519

Mortality:

5000 mg/kg : 1/5 males died 2/5 females died
5700 mg/kg : 3/5 males died 2/5 females died
6500 mg/kg : 3/5 males died 5/5 females died

The deaths occurred within 1 hour after dosing.

Clinical signs:

other: 5000 mg/kg : lethargy and hunched posture 5700 mg/kg : lethargy, clonic spasms, hunched posture, uncoordinated movements, piloerection and red staining of the eyes 6500 mg/kg : lethargy, clonic spasms, ventro-lateral recumbency and uncoordinated movements

Gross pathology:

At macroscopic post mortem examination, haemorrhages in the stomach glundular mucosa were found in all the animals that died during the studuy. Black/brown discolouration of the liver was also seen in all decedents treated at 6500 mg/kg bw. No abnormalities were found in the surviving animals at termination.

Applicant's summary and conclusion

Conclusions:

The oral LD50 values of OSZ in rats were calculated to be 5838 mg/kg bw for the males, 5421 mg/kg bw for the females and 5592 mg/kg bw for the sexes combined. Due to mortality distribution, no fiducial limits could be determined for the LD50 values for the males or females.