4,10-dibromodibenzo[def,mno]chrysene-6,12-dione

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or no or minor methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions.

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

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4,10-dibromodibenzo[def,mno]chrysene-6,12-dione

EC Number:

224-481-3

EC Name:

4,10-dibromodibenzo[def,mno]chrysene-6,12-dione

Cas Number:

4378-61-4

Molecular formula:

C22H8Br2O2

IUPAC Name:

4,10-dibromonaphtho[7,8,1,2,3-nopqr]tetraphene-6,12-dione

Test material form:

solid: nanoform

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 a reputable supplier. For full details please see full study report. 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. The weight variation did not exceed ±20% of the mean weight for each sex.
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. Free access to mains drinking water and food (2014C Teklad Global Rodent diet supplied by Harlan Laboratories UK Ltd., Oxon, UK) 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.
The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

other: distilled water

Details on dermal exposure:

On the day before treatment the back and flanks of each animal were clipped free of hair.
Using available information on the toxicity of the test item, a group of five male and five female rats was 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.

Duration of exposure:

24 hours

Doses:

2000 mg/kg body weight

No. of animals per sex per dose:

5

Control animals:

not required

Details on study design:

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

Using available information on the toxicity of the test item, a group of five male and five female rats was 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.

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. The animals were returned to group housing for the remainder of the study period.

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 following scale from Draize J H (1977) "Dermal and Eye Toxicity Tests" In: Principles and Procedures for Evaluating the Toxicity of Household Substances, National Academy of Sciences, Washington DC p.31:

EVALUATION OF SKIN REACTIONS
Erythema and Eschar Formation Value

No erythema 0
Very slight erythema (barely perceptible) 1
Well-defined erythema 2
Moderate to severe erythema 3
Severe erythema (beef redness) to slight eschar formation (injuries in depth) 4

Oedema Formation

No oedema 0
Very slight oedema (barely perceptible) 1
Slight oedema (edges of area well-defined by definite raising) 2
Moderate oedema (raised approximately 1 millimetre) 3
Severe oedema (raised more than 1 millimetre and extending beyond the area of exposure) 4

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.
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:

No statistical analysis was performed.

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:

Red coloured staining was noted at the test sites of all animals during the study. The staining prevented accurate evaluation of erythema in all animals one and two days after dosing.
There were no signs of dermal irritation noted.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Remarks:

Regulation (EC) 1272/2008

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” (adopted24 February 1987)

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

 

Method. 

A group of ten animals (five males and five females) was 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. 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. 

No signs of dermal irritation were noted.

 

Bodyweight. 

Animals showed expected gains in bodyweight over the study period except two male animals that showed bodyweight loss over the first week but expected gain in bodyweight over 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.