Dibutyltin oxide

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19 May 2010 to 02 June 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Dibutyltin oxide

EC Number:

212-449-1

EC Name:

Dibutyltin oxide

Cas Number:

818-08-6

Molecular formula:

C8H18OSn

IUPAC Name:

dibutylstannanone

Details on test material:

Sponsor's identification: CAS No 818-08-6
Description: white solid
Batch number: not supplied
Date received: 26 March 2010
Expiry date: 26 March 2011
Storage conditions: approximately 4°C in the dark under nitrogen

The integrity of supplied data relating to the identity, purity and stability of the test material is the responsibility of the Sponsor.

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories U.K. Ltd., Oxon, UK.
- Age at study initiation: eight to twelve weeks
- Weight at study initiation: at least 200g. The weight variation did not exceed ± 20% of the mean weight for each sex.
- Housing: The animals were housed in suspended solid floor polypropylene cages furnished with woodflakes. The animals were housed individually during the 24-hour exposure period and in groups of five, by sex, for the remainder of the study.
- Diet /water(e.g. ad libitum): Free access to mains drinking water and food (2014 Teklad Global Rodent diet supplied by Harlan Laboratories U.K. Ltd., Oxon, UK) was allowed throughout the study.
- Acclimation period: at least five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 25°C
- Humidity (%): 30 to 70%
- Air changes (per hr): The rate of air exchange was at least fifteen changes per hour
- Photoperiod (hrs dark / hrs light): lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

arachis oil

Details on dermal exposure:

TEST SITE
- % coverage: approximately 10% of the total body surface area
- Type of wrap if used: A piece of surgical gauze was placed over the treatment area and semi-occluded with a piece of self adhesive bandage.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): After the 24-hour contact period the bandage was carefully removed and the treated skin and surrounding hair wiped with cotton wool moistened with arachis oil BP to remove any residual test material.
- Time after start of exposure: 24 hours

Duration of exposure:

24 hours

Doses:

Using available information on the toxicity of the test material, a group of five male and five female rats was treated with the test material at a dose level of 2000 mg/kg.

No. of animals per sex per dose:

five male and five female rats

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The animals were observed for deaths or overt signs of toxicity ½, 1, 2 and 4 hours after dosing and subsequently once daily for fourteen days. Individual bodyweights were recorded prior to application of the test material on Day 0 and on Days 7 and 14.
- Necropsy of survivors performed: yes
- Other examinations performed: At the end of the study the animals were killed by cervical dislocation. All animals were subjected to gross necropsy. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Statistics:

Data evaluations included the relationship, if any, between the exposure of the animal to the test material and the incidence and severity of all abnormalities including behavioural and clinical observations, gross lesions, bodyweight changes, mortality and any other toxicological effects.
Using the mortality data obtained, an estimate of the acute dermal median lethal dose (LD50) of the test material was made.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no deaths.

Clinical signs:

other: There were no signs of systemic toxicity.

Gross pathology:

No abnormalities were noted at necropsy.

Other findings:

Well-defined erythema and very slight oedema were noted at the test sites of all animals. Other dermal reactions noted were haemorrhage of dermal capillaries, loss of skin elasticity and flexibility, small superficial scattered scabs, hardened light brown coloured scab, scab lifting to reveal glossy skin, scab undulating, scab cracking and glossy skin. Adverse dermal reactions prevented accurate evaluation of erythema and oedema at the test sites of all animals during the study.

Any other information on results incl. tables

The acute dermal median lethal dose (LD₅₀) of the test material in the Wistar strain rat was found to be greater than 2000 mg/kg bodyweight.

Applicant's summary and conclusion

Interpretation of results:

other: Not classified according to EU criteria

Conclusions:

The acute dermal median lethal dose (LD50) of the test material in the Wistar strain rat was found to be greater than 2000 mg/kg bodyweight.

Executive summary:

The study was performed to assess the acute dermal toxicity of the test material in the Wistar strain rat. The method was designed to meet the requirements of the following:

 OECD Guidelines for the Testing of Chemicals No. 402 “Acute Dermal Toxicity” (adopted 24 February 1987)

 Method B3 Acute Toxicity (Dermal) of Commission Regulation (EC) No. 440/2008

A group of ten animals (five males and five females) was given a single, 24 hour, semi occluded dermal application of the test material to intact skin at a dose level of 2000 mg/kg bodyweight. Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy.

There were no deaths or signs of systemic toxicity.

Well-defined erythema and very slight oedema were noted at the test sites of all animals. Other dermal reactions noted were haemorrhage of dermal capillaries, loss of skin elasticity and flexibility, small superficial scattered scabs, hardened light brown coloured scab, scab lifting to reveal glossy skin, scab undulating, scab cracking and glossy skin.

All males showed expected gains in bodyweight over the study period. Bodyweight loss was noted in all females during the first week with expected gain in bodyweight during the second week.

No abnormalities were noted at necropsy.

The acute dermal median lethal dose (LD50) of the test material in the Wistar strain rat was found to be greater than 2000 mg/kg bodyweight.