Carbonohydrazide

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was performed between 21 September 2011 and 12 October 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

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

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (MAFF), Testing Guidelines for Toxicology Studies, 12 NohSan No. 8147, amended 26 June 2001

Deviations:

no

Test guideline 5

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Health and Welfare, 1992

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Carbohydrazide

IUPAC Name:

Carbohydrazide

Test material form:

other: solid

Details on test material:

Sponsor's identification: Carbohydrazide
Identifier : TIS I0352
CAS number : 497-18-7
Description : white solid
Batch number : OJ24-21M
Date received : 04 April 2011
Expiry date : 24 January 2013
Storage conditions: room temperature in the dark, over silica gel

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Five male and five female Wistar (RccHan™:WIST) strain rats were supplied by Harlan Laboratories UK Ltd, UK. On receipt the animals were randomly allocated to cages. The females were nulliparous and non-pregnant. After an acclimatisation period of at least five days the animals were selected at random and given a number unique within the study by indelible ink-marking on the tail and a number written on a cage card. At the start of the study the animals weighed at least 200g, and were eight to twelve weeks of age. One male animal was outside the ± 20% weight variation for this sex. This deviation was considered not to affect the purpose or integrity of the study.

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 up to four, by sex, for the remainder of the study. Free access to mains drinking water and food (2014C Teklad Global Rodent diet was allowed throughout the study. The diet, drinking water and bedding were routinely analysed and were considered not to contain any contaminants that could reasonably be expected to affect the purpose or integrity of the study.

The temperature and relative humidity were set to achieve limits of 19 to 25°C and 30 to 70% respectively. Any occasional deviations from these targets were considered not to have affected the purpose or integrity of the study. The rate of air exchange was at least fifteen changes per hour and the 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:

other: moistened with distilled water

Details on dermal exposure:

PREPARATION OF TEST ITEM:
For the purpose of the study the test item was ground to a fine powder using a mortar and pestle, weighed out according to each animal's individual bodyweight and moistened with distilled water prior to application.
The absorption of the test item was not determined.


TEST SITE
On the day before treatment the back and flanks of each animal were clipped free of hair.

In the absence of data suggesting the test item was toxic, one male and one female rat were initially treated with the test item at a dose level of 2000 mg/kg.

The appropriate amount of test item, moistened with distilled water, was applied as evenly as possible to an area of shorn skin (approximately 10% of the total body surface area). A piece of surgical gauze was placed over the treatment area and semi-occluded with a piece of self-adhesive bandage. The animals were caged individually for the 24-Hour exposure period. Shortly after dosing the dressings were examined to ensure that they were securely in place.

REMOVAL OF TEST SUBSTANCE:
After the 24-Hour contact period the bandage was carefully removed and the treated skin and surrounding hair wiped with cotton wool moistened with distilled water to remove any residual test item.

Duration of exposure:

24 hours

Doses:

2000 mg/kg bodyweight

No. of animals per sex per dose:

5 male and 5 female in total (initially 1 male and 1 female, then a further group of 4 males and 4 females).

Control animals:

no

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.

After removal of the dressings and subsequently once daily for fourteen days, the test sites were examined for evidence of primary irritation and scored according to the Draize scale (see evaluation of skin reactions).

Any other skin reactions, if present were also recorded.

Individual bodyweights were recorded prior to application of the test item on Day 0 and on Days 7 and 14.

- Necropsy of survivors performed: yes
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.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: 95% confidence limits not reported.

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:

Dermal Reactions
Very slight erythema was noted at the test sites of one male and one female, which cleared by day 5. There were no other signs of dermal irritation noted.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

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

Executive summary:

Introduction.

The study was performed to assess the acute dermal toxicity of the test item in the Wistar strain rat. The method was designed to be compatible with 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

-Environmental Protection Agency Health Effects Gudelines OPPTS 870.1200 Acute Dermal Toxicity August 1998

- Japanese Mistry of Agriculture, Forestry and Fisheries (MAFF), Testing Guidelines for Toxicology Studies, 12 NohSan No. 8147, amended 26 June 2001

- Japanese Ministry of Health and Welfare, 1992

Method.

Initially, two animals (one male and one female) were given a single, 24 hour, semi-occluded dermal application of the test item to intact skin at a dose level of 2000 mg/kg bodyweight. Based on the results of the initial test, a further group of eight animals (four males and four females) was similarly treated. Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy.

Mortality.

There were no deaths.

Clinical Observations.

There were no signs of systemic toxicity.

Dermal Irritation.

Very slight erythema was noted at the test sites of one male and one female. There were no other signs of dermal irritation noted.

Bodyweight.

All animals showed expected gains in bodyweight over the study period, except for one female which showed,a slight bodyweight loss during the second week.

Necropsy.

No abnormalities were noted at necropsy.

Conclusion.

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

The test item did not meet the criteria for classification according to the Classification, Labelling and Packaging Regulation or the Globally Harmonised Classification System.