m,m'-[carbonylbis[imino(3-methoxy-p-phenylene)azo]]bis(benzenesulphonic) acid, compound with 2,2'-iminodiethanol (1:2)

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental start date: 06 March 2018 Experimental completion date: 20 March 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

m,m'-[carbonylbis[imino(3-methoxy-p-phenylene)azo]]bis(benzenesulphonic) acid, compound with 2,2'-iminodiethanol (1:2)

EC Number:

275-602-1

EC Name:

m,m'-[carbonylbis[imino(3-methoxy-p-phenylene)azo]]bis(benzenesulphonic) acid, compound with 2,2'-iminodiethanol (1:2)

Cas Number:

71550-21-5

Molecular formula:

C27H24N6O9S2.2C4H11NO2

IUPAC Name:

m,m'-[carbonylbis[imino(3-methoxy-p-phenylene)azo]]bis(benzenesulphonic) acid, compound with 2,2'-iminodiethanol (1:2)

Test material form:

liquid

Specific details on test material used for the study:

Physical state / Appearance: amber coloured solid pieces (Sponsors description: Russet coloured crystalline solid)
Expiry Date: 22 June 2018
Storage Conditions: room temperature in the dark

For the purpose of the study the test item was used as supplied. At the request of the sponsor a correction factor of 1.12 was applied to all doses.
The absorption of the test item was not determined.

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Animal Information
Five male and five female Wistar (RccHan:WIST) strain rats were supplied by Envigo RMS (UK) Limited, Oxon, UK. On receipt the animals were randomly allocated to cages. The females were nulliparous and non pregnant. After an acclimatization period of at least 5 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 200 g, and were 8 to 12 weeks of age. The weight variation did not exceed ±20% of the mean weight for each sex.

Animal Care and Husbandry
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 Envigo RMS (UK) Limited, Oxon, UK) was allowed throughout the study. The diet, drinking water and bedding were routinely analyzed 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 ºC and 30 to 70% respectively. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give 12 hours continuous light and 12 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:

unchanged (no vehicle)

Remarks:

moistened with arachis oil BP

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 2240 mg/kg (equivalent to 2000 mg active ingredient/kg body weight).
The calculated volume of test item, ground to a fine powder, moistened with arachis oil BP, was applied as evenly as possible to an area of shorn skin (approximately 10% of the total body surface area) using a graduated syringe. 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 arachis oil BP 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 approximately 30 minutes, 1, 2 and 4 hours after dosing and subsequently once daily for 14 days.

Duration of exposure:

24 hr

Doses:

2240 mg/kg (equivalent to 2000 mg active ingredient/kg body weight)

No. of animals per sex per dose:

5 males and 5 females

Control animals:

no

Details on study design:

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

Edema Formation
No edema 0
Very slight edema (barely perceptible) 1
Slight edema (edges of area well-defined by definite raising) 2
Moderate edema (raised approximately 1 millimeter) 3
Severe edema (raised more than 1 millimeter and extending beyond the area of exposure) 4
Any other skin reactions, if present were also recorded.


Individual body weights 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.

Results and discussion

Effect levels

Effect levels 1

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 240 mg/kg bw

Based on:

test mat.

Effect levels 2

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

act. ingr.

Mortality:

There were no deaths.

Clinical signs:

other: No signs of systemic toxicity were noted during the observation period.

Gross pathology:

No abnormalities were noted at necropsy.

Other findings:

Dermal reactions
Very slight erythema was noted at the treatment sites of all male animals on Days 1 and 2 and persisted at the treatment sites of two male animals on Day 3. Very slight erythema was noted at the treatment sites of two female animals on Day 1. Treatment sites appeared normal on Days 2, 3 or 4.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2240 mg/kg body weight (equivalent to 2000 mg active ingredient/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.

Methods

A group of ten animals (five males and five females) were given a single, 24 hour, semi‑occluded dermal application of the undiluted test item to intact skin at a dose level of 2240 mg/kg body weight(equivalent to 2000 mg active ingredient/kg body weight). Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy.

Results

Mortality. There were no deaths.

Clinical Observations. There were no signs of systemic toxicity.

Dermal Irritation. Very slight erythema was noted at the treatment sites of all male animals on Days 1 and 2 and persisted at the treatment sites of two male animals on Day 3. Very slight erythema was noted at the treatment sites of two female animals on Day 1. Treatment sites appeared normal on Days 2, 3 or 4.

Body Weight. All animals showed expected gains in body weight over the observation period except for three females which showed a body weight loss during the first week but expected gain in body weight 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 2240 mg/kg body weight (equivalent to 2000 mg active ingredient/kg body weight).