Registration Dossier

Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
The study was performed between 25 April 2012 and 09 May 2012.
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
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

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.3 (Acute Toxicity (Dermal))
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.1200 (Acute Dermal Toxicity)
Deviations:
no
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
Qualifier:
according to guideline
Guideline:
other: Japanese Ministry of Health and Welfare, 1992
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Test type:
standard acute method
Limit test:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
N-isopropylmethacrylamide
EC Number:
237-331-7
EC Name:
N-isopropylmethacrylamide
Cas Number:
13749-61-6
Molecular formula:
C7H13NO
IUPAC Name:
2-methyl-N-(propan-2-yl)prop-2-enamide
Test material form:
other: solid
Details on test material:
Sponsor's identification : N-Isopropylmethacrylamide (NIPMAA)
Identifiers : TIS O4310, R-50621
CAS number : 13749-61-6
Description : yellow crystalline solid
Batch number : CI1L0212
Date received : 16 January 2012
Expiry date : 01 November 2012
Storage conditions : room temperature in the dark

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Five male and five female Wistar (RccHan:WIST) strain rats were supplied by Harlan Laboratories UK Ltd
- Age at study initiation: Eight to twelve weeks.
- Weight at study initiation: At least 200 g (weight variation did not exceed ±20% of the mean weight for each sex,
- Fasting period before study: None.
- 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 (e.g. ad libitum): Free access to mains drinking water was allowed throughout the study.
- Water (e.g. ad libitum): Free access to food was allowed throughout the study.
- Acclimation period: At least five days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Set to achieve limits of 19 to 25°C.
- Humidity (%): Set to achieve limits of 30 to 70% respectively.
- Air changes (per hr): At least fifteen changes per hour.
- Photoperiod (hrs dark / hrs light): Lighting was controlled by a time switch to give twelve hours continuous light and twelve hours darkness.

Administration / exposure

Type of coverage:
semiocclusive
Vehicle:
other: test item moistened with arachis oil BP
Details on dermal exposure:
PREPARATION OF TEST ITEM:
For the purpose of the study a correction factor was applied to account for 8.7% water content of the test item. The test item was weighed out according to each animal’s individual bodyweight and moistened with arachis oil BP prior to application.

TEST SITE
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 2191 mg/kg (equivalent to 2000 mg active ingredient/kg bodyweight).

The appropriate amount of test item, 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). 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 arachis oil BP to remove any residual test item. The animals were returned to group housing for the remainder of the study period.





Duration of exposure:
24 hours.
Doses:
Dose level of 2191 mg/kg (equivalent to 2000 mg active ingredient/kg bodyweight).
No. of animals per sex per dose:
5 males and 5 females at 2191 mg/kg (equivalent to 2000 mg active ingredient/kg bodyweight).
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:
act. ingr.
Mortality:
There were no deaths.
Clinical signs:
There were no signs of systemic toxicity.
See Table 1 (attached background material).
Body weight:
All animals showed expected gains in bodyweight over the study period.
Individual bodyweights and weekly bodyweight changes are given in Table 4 (see attached background material).
Gross pathology:
Epithelial sloughing of the gastric mucosa was noted at necropsy of two females. No abnormalities were noted at necropsy of the remaining animals.
Individual necropsy findings are given in Table 5 (see attached background material).
Other findings:
DERMAL REACTIONS:
Very slight erythema was noted at the test sites of eight animals. Very slight oedema was also noted at the test site of one female. Other signs of skin irritation noted were light brown discolouration of the epidermis, small superficial scattered scabs and crust formation. There were no signs of dermal irritation noted at the test sites of two females.

Individual dermal reactions are given in Table 2 and Table 3 (see attached background material).

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 2191 mg/kg bodyweight (equivalent to 2000 mg active ingredient/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

- United States Environmental Protection Agency Health Effects Test Guidelines OPPTS 870.1200 Acute Dermal Toxicity August 1998

- Japanese Ministry 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.

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 2191 mg/kg bodyweight (equivalent to 2000 mg active ingredient/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.

Very slight erythema was noted at the test sites of eight animals. Very slight oedema was also noted at the test site of one female. Other signs of skin irritation noted were light brown discolouration of the epidermis, small superficial scattered scabs and crust formation. There were no signs of dermal irritation noted at the test sites of two females.

Bodyweight.

All animals showed expected gains in bodyweight over the study period.

Necropsy.

Epithelial sloughing of the gastric mucosa was noted at necropsy of two females. No abnormalities were noted at necropsy of the remaining animals.

Conclusion.

The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2191 mg/kg bodyweight (equivalent to 2000 mg active ingredient/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.