2-[(4-chloro-2-nitrophenyl)azo]-N-(2-chlorophenyl)-3-oxobutyramide

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 07 DEC 2011 to 21 DEC 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD 402) and according to GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

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:

2-[(4-methyl-2-nitrophenyl)azo]-3-oxo-N-phenylbutyramide

EC Number:

219-730-8

EC Name:

2-[(4-methyl-2-nitrophenyl)azo]-3-oxo-N-phenylbutyramide

Cas Number:

2512-29-0

Molecular formula:

C17H16N4O4

IUPAC Name:

2-[(4-methyl-2-nitrophenyl)diazenyl]-3-oxo-N-phenylbutanamide

Test material form:

solid: nanoform, no surface treatment

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.
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 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:

arachis oil

Details on dermal exposure:

The appropriate amount of test item, mixed with arachis oil BP, was applied as evenly as possible to an area of shaved skin (approximately 10% of the total body surface area).

Duration of exposure:

24 hours

Doses:

2000 mg/kg body weight

No. of animals per sex per dose:

5 Male
5 Female

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of weighing: weekly
- Frequency of observations: first day: 4 times, thereafter once daily
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, dermal reactions

Statistics:

No statistical analysis was performed.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: no animal died within the observation period

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

Yellow 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 day after dosing.
Very slight erythema was noted at the test site of one female five to eight days after dosing. Crust formation and small superficial scattered scabs were also noted at this site. There were no signs of dermal irritation noted in the remaining animals.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

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 body weight.

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 CommissionRegulation (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 body weight 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 site of one female. Crust formation and small superficial scattered scabs were also noted at this site. No other signs of dermal irritation were noted. 

 

Body weight. 

Animals showed expected gains in body weight over the study period except for one female which showed expected gain in body weight during the first week but slight body weight 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 body weight.