Strontium titanium trioxide

Endpoint summary

Description of key information

The acute lethal oral dose (LD50) to rats of ST888YK was demonstrated to be greater than 2000 mg/kg bodyweight.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 April 2002 and 09 May 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficincies, which do not affect the quality of relevant results.

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Animals chosen for this study were selected from a stock supply of healthy male and female CD rats of Sprague-Dawley origin (Hsd:Sprague-Dawley(CD)) obtained from Harlan U.K. Ltd., Bicester, Oxon, England.
They were in the weight range of 86 to 117 g and approximately five to seven weeks of age prior to dosing (Day 1). All the rats were acclimatised to the experimental environment for a minimum period of five days prior to start of treatment.
Rats were allocated without conscious bias to cages within the treatment groups. They were housed in groups of three rats of the same sex in metal cages with wire.
A standard laboratory rodent diet (Special Diet Services RM1(E) SQC expanded pellet) and drinking water were provided ad libitum. Access to food only was prevented overnight prior to and approximately four hours after dosing. The batch(es) of diet used for the study was analysed for certain nutrients, possible contaminants and micro-organisms. Results of routine physical and chemical examination of drinking water, as conducted by the supplier, are made available to Huntingdon Life Sciences Ltd. at regular intervals throughout the year.
Animal room temperature was maintained in the range 22± 3°C and relative humidity 40 - 70%. Any minor deviations from these ranges would not have had an adverse effect on the animals and would not affect the integrity or validity of the study. These environmental parameters were recorded daily and the permanent record archived with other departmental raw data. Lighting was controlled by means of a time switch to provide 12 hours of artificial light (0600 - 1800 hours GMT) in each 24-hour period.
Each animal was identified by tail marking. Each cage was identified by a coloured label displaying the dose level, study number, animal mark and the initials ofthe Study Director and Home Office licensee.

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

VEHICLE
ST888YK was formulated at a concentration of 200 mg/mL in corn oil and administered at a volume of 10 mL/kg bodyweight.

DOSAGE PREPARATION
The test substance was prepared on the day of dosing.
The absorption of the test substance was not determined.
Chemical analysis of the homogeneity, stability and purity of the test substance was not undertaken as part of this study and remains the responsibility of the Sponsor.
A group of three fasted female rats received a single oral gavage dose of the test substance, formulated in corn oil, at a dose level of 2000 mg/kg. As results at this dosage indicated the acute lethal oral dose of the test material to be greater than 2000 mg/kg bodyweight, in compliance with the study guidelines,
a group of three fasted males was dosed at 2000 mg/kg to confirm results at this dosage and complete the study.
The treatment regime and constitution ofthe groups are shown below:

Dose (mg/kg) Concentration (mg/mL) No. of rats
Male Female
2000 200 3 3

Doses:

2000 mg/kg dosed once

No. of animals per sex per dose:

3 animals per sex, per dose.

Control animals:

no

Details on study design:

ADMINISTRATION OF THE TEST SUBSTANCE
The appropriate dose volume of the test substance was administered to each rat by oral gavage using a plastic syringe and catheter (8 ch).
The day of dosing was designated Day 1.

OBSERVATIONS
Mortality
Cages of rats were checked at least twice daily for any mortalities.
Clinical signs
Animals were observed soon after dosing and at frequent intervals for the remainder of Day 1. On subsequent days, animals were observed once in the morning and again at the end of the experimental day (with the exception of Day 15 - morning only). The nature and severity of the clinical signs and time were recorded at each observation.
All animals were observed for 14 days after dosing.
Bodyweight
The bodyweight of each rat was recorded on Days 1 (prior to dosing), 8 and 15. Individual weekly bodyweight changes and group mean bodyweights were calculated.

TERMINAL STUDIES
Termination
All animals were killed on Day 15 by carbon dioxide asphyxiation.
Macroscopic pathology
All animals were subjected to a macroscopic examination which consisted of opening the cranial, thoracic and abdominal cavities. The macroscopic appearance of all examined organs was recorded.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no deaths following a single oral gavage dose of ST888YK to a group of six rats (three males and three females) at a dose level of 2000 mglkg bodyweight.

Clinical signs:

other: Clinical signs of reaction to treatment were recorded on Day 2 only, and were confined to pale brown faeces seen in all animals. Recovery of rats, as judged by external appearance and behaviour, was complete by Day 3.

Gross pathology:

No abnormalities were revealed in any animal at the macroscopic examination at study termination on Day 15.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute lethal oral dose (LD50) to rats of ST888YK was demonstrated to be greater than 2000 mg/kg bodyweight.

Executive summary:

This study was performed to assess the acute oral toxicity of ST888YK to the rat. The method followed was that described in:

EEC Methods for the determination of toxicity, Annex to Directive 96/54/EEC (Official Journal No. L248, 30.9.96), Part B, Method B.l tris. Acute toxicity (oral) - acute toxic class method.

OECD Guideline for Testing of Chemicals No.423 'Acute Oral Toxicity - Acute Toxic Class Method' Adopted 22 March 1996.

A group of three fasted female rats received a single oral gavage dose of the test substance, formulated in corn oil, at a dose level of 2000 mg/kg. As results at this dosage indicated the acute lethal oral dose of the test material to be greater than 2000 mg/kg bodyweight, in compliance with the study guidelines, a group of three fasted males was dosed at 2000 mg/kg to confirm results at this dosage and complete the study.

All animals were killed as scheduled and examined macroscopically on Day 15, the end of the observation period.

Clinical signs of reaction to treatment were recorded on Day 2 only, and were confined to pale brown faeces seen in all animals. Recovery of rats, as judged by external appearance and behaviour, was complete by Day 3.

All animals were considered to have achieved satisfactory bodyweight gains throughout the study.

No abnormalities were revealed in any animal at the macroscopic examination at study termination on Day 15.

The acute lethal oral dose (LD₅₀) to rats of ST888YK was demonstrated to be greater than 2000 mg/kg bodyweight.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Justification for selection of acute toxicity – oral endpoint
The acute lethal oral dose (LD50) to rats of ST888YK was demonstrated to be greater than 2000 mg/kg bodyweight.

Justification for classification or non-classification

This study was performed to assess the acute oral toxicity of ST888YK to the rat. The method followed was that described in:

EEC Methods for the determination of toxicity, Annex to Directive 96/54/EEC (Official Journal No. L248, 30.9.96), Part B, Method B.l tris. Acute toxicity (oral) - acute toxic class method.

OECD Guideline for Testing of Chemicals No.423 'Acute Oral Toxicity - Acute Toxic Class Method' Adopted 22 March 1996.

A group of three fasted female rats received a single oral gavage dose of the test substance, formulated in corn oil, at a dose level of 2000 mg/kg. As results at this dosage indicated the acute lethal oral dose of the test material to be greater than 2000 mg/kg bodyweight, in compliance with the study guidelines, a group of three fasted males was dosed at 2000 mg/kg to confirm results at this dosage and complete the study.

All animals were killed as scheduled and examined macroscopically on Day 15, the end of the observation period.

Clinical signs of reaction to treatment were recorded on Day 2 only, and were confined to pale brown faeces seen in all animals. Recovery of rats, as judged by external appearance and behaviour, was complete by Day 3.

All animals were considered to have achieved satisfactory bodyweight gains throughout the study.

No abnormalities were revealed in any animal at the macroscopic examination at study termination on Day 15.

The acute lethal oral dose (LD₅₀) to rats of ST888YK was demonstrated to be greater than 2000 mg/kg bodyweight.

Based on the above information, the test material is not considered to be classified for acute oral toxicity.