Ruthenium (IV) oxide

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13 January 1982 – 4 February 1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Although no indication that a specific guideline was followed, the study was to GLP, and appears scientifically acceptable and well reported.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

Principles of method if other than guideline:

A single acute oral administration of ruthenium (IV) oxide was given to rats at 2000 mg/kg bw (the highest dose causing no deaths in a range-finding study).

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Ruthenium dioxide (hydrate)

Cas Number:

32740-79-7

IUPAC Name:

Ruthenium dioxide (hydrate)

Constituent 2

Reference substance name:

Ruthenium IV oxide hydrate

IUPAC Name:

Ruthenium IV oxide hydrate

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): ruthenium (IV) oxide-water (1/n)
- Molecular formula (if other than submission substance): RuO2
- Substance type: black powder
- Physical state: solid
-Purity: no data
- Lot/batch No.: 061151

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Tuck & Sons Ltd, Battlesbridge, Essex
- Weight at study initiation: 172-225 g
- Fasting period before study: overnight (16-20 hrs) fast directly before treatment
- Housing: maximum of 5 rats (of onesex) in polypropylene cages
- Diet: ad libitum rat diet supplied by Nottingham University, School of Agriculture, Sutton Bonington, Near Loughborough, Leics
- Water: ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Air changes (per hr): minimum of 20 air changes per hr
- Photoperiod (hrs dark / hrs light): 12 hrs light, 12 hrs dark with no daylight

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

arachis oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 100 mg/ml
- Amount of vehicle (if gavage): 0.25-20.0 ml/kg

MAXIMUM DOSE VOLUME APPLIED: 20 ml/kg

Doses:

In the range-finding study, male and female rats were administered 25, 50, 200, 500 or 2000 mg/kg bw using an all metal stomach tube. In the main study male and female rats were administered 2000 mg/kg bw.

No. of animals per sex per dose:

One rat/sex/dose in the range finding study, five rats/sex/dose in the main study.

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: ½, 1 and 4 hrs following dosing and then once daily for 14 days.
- Necropsy of survivors performed: no
- Other examinations performed: clinical signs

Statistics:

Acute oral median lethal dose (LD50)

Results and discussion

Preliminary study:

In the range-finding study, no deaths were recorded within the 5 day observation period.

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

No deaths were reported in the range-finding or the main study throughout the 5-day and 14-day observation periods respectively.

Clinical signs:

other: Subdued activity and pilar erection within the first hr were the only clinical effects seen.

Gross pathology:

Not reported.

Applicant's summary and conclusion

Interpretation of results:

not classified

Conclusions:

In a GLP study, similar/equivalent to OECD guidelines, the acute oral LD50 of ruthenium (IV) oxide hydrate in rats was found to be greater than 2000 mg/kg bw.

Executive summary:

Ruthenium (IV) oxide hydrate was tested for its acute oral toxicity in rats, in a GLP study similar/equivalent to OECD Test Guideline 401. In a range finding study, one male and one female rat/group were administered 25, 50, 200, 500 or 2000 mg ruthenium (IV) oxide hydrate/kg bw by stomach tube. No deaths were recorded within the 5-day observation period and, therefore, in the main study, 5 rats/sex were given 2000 mg/kg bw (the highest dose causing no deaths in the range-finding study) by stomach tube. No deaths were again recorded during the 14-day observation period.

 

Based on the results of this study, ruthenium (IV) oxide should not be classified for acute oral toxicity according to EU CLP criteria (EU 1272/2008).