N-isopropylmethacrylamide

Endpoint summary

Description of key information

The acute oral median lethal dose (LD50) of the test material in the female Sprague-Dawley CD strain rat was estimated to be greater than 2000 mg/kg bodyweight.
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).

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was performed between 25 October 2007 and 21 November 2007

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.

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Female Sprague-Dawley CD (Crl : CD® (SD) IGS BR) strain rats were supplied by Charles River (UK) Ltd. The females were nulliparous and non-pregnant.
- Age at study initiation: At the start of the study the animals were eight to twelve weeks of age.
- Weight at study initiation: 206 - 241 g. The bodyweight variation did not exceed ± 29% of the initial/mean bodyweight of any previously dosed animals.
- Fasting period before study: Overnight fast immediately before dosing and for approximately three to four hours after dosing.
- Housing: The animals were housed in groups of up to four in suspended solid-floor polypropylene cages furnished with woodflakes.
- Diet (e.g. ad libitum): Free access to food (Certified Rate and Mouse Diet) was allowed throughout the study.
- Water (e.g. ad libitum): Free access to mains drinking water 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 acheive limits of 30 to 70%.
- Air changes (per hr): At least fifteen air changes per hour.
- Photoperiod (hrs dark / hrs light): lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.

Route of administration:

oral: gavage

Vehicle:

DMSO

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 30 mg/ml (for 300 mg/kg dose level) and 200 mg/ml (for 2000 mg/kg dose level).

- Justification for choice of vehicle: Dimethyl sulphoxide was used because the test material did not dissolve/suspend in distilled water or arachis oil BP.

MAXIMUM DOSE VOLUME APPLIED: 10 ml/kg

DOSAGE PREPARATION: For the purpose of the study the test material was freshly prepared, as required, as a solution dimethyl sulphoxide.
All animals were dosed once only by gavage, using a metal cannula attached to a graduated syringe. The volume administered to each animal was calculated according to the fasted bodyweight at the time of dosing. Treatment of animals was sequential. Sufficient time was allowed between each dose level to confirm the survival of the previously dosed animals.

Doses:

300 mg/kg and 2000 mg/kg

No. of animals per sex per dose:

1 female at 300 mg/kg.
5 females at 2000 mg/kg.

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days

- Frequency of observations and weighing: Clinical observations were made 1/2, 1, 2, and 4 hours after dosing and then daily for fourteen days. Morbidity and mortality checks were made twice daily. Individual bodyweights were recorded on Day 0 (the day of dosing) and on Days 7 and 14.

- Necropsy of survivors performed: yes - At the end of the observation period 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.

Preliminary study:

Dose Level 300 mg/kg:
Individual clinical observations and mortality data are given in Table 1.

Mortality: There was no death
Clinical observations: No signs of systemic toxicity were noted during the observation period.
Bodyweight: Individual bodyweights and bodyweight changes are given in Table 2. The animal showed expected gains in bodyweight over the observation period.
Necropsy: Individual necropsy findings are given in Table 3. No abnormalities were noted at necropsy.

Based on this information, a dose level of 2000 mg/kg bodyweight was selected for the main test.

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

Dose Level 2000 mg/kg: Individual clinical observations and mortality data are given in Table 4.
There were no deaths.

Clinical signs:

other: Hunched posture, lethargy, ataxia and pilo-erection were noted in all animals treated at a dose level of 2000 mg/kg. One animal appeared normal one day after dosing and the remaining animals appeared normal two days after dosing.

Gross pathology:

Individual necropsy findings are given in Table 6.
No abnormalities were noted at necropsy.

See attached background material for Tables 1 -6.

Interpretation of results:

GHS criteria not met

Conclusions:

The acute oral median lethal dose (LD50) of the test material in the female Sprague-Dawley CD strain rat was estimated to be greater than 2000 mg/kg bodyweight.

Executive summary:

Introduction.

The study was performed to assess the acute oral toxicity of the test material in the Sprague-Dawley CD strain rat. The method was designed to meet the requirements of the following:

• OECD Guidelines for Testing of Chemicals No 420 "Acute Oral Toxicity - Fixed Dose

Method" (200 I)

• Method BI bis Acute Toxicity (Oral) of Commission Directive 2004/73/EC

Method.

Following a sighting test at dose levels of 300 mg/kg and 2000 mg/kg, a further group of four fasted females was given a single oral dose of test material, as a solution in dimethyl sulphoxide, 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.

Signs of systemic toxicity noted in animals treated at a dose level of 2000 mg/kg were hunched posture, lethargy, ataxia and pilo-erection. There were no signs of systemic toxicity noted in the animal treated at a dose level of 300 mg/kg.

Bodyweight.

All animals showed expected gains in bodyweight.

Necropsy.

No abnormalities were noted at necropsy.

Conclusion.

The acute oral median lethal dose (LD₅₀) of the test material in the female Sprague-Dawley CD strain rat was estimated to be greater than 2000 mg/kg bodyweight.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

The study has been conducted according to OECD Guideline 420 and GLP and is adequately reported. The study has been assigned a reliability 1.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

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.

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

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.

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.

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: There were no signs of systemic toxicity. See Table 1 (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).

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.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

The study has been conducted according to OECD Guideline 402 and GLP and is adequately reported. The study has been assigned areliability 1.

Additional information

Acute Oral Toxicity:

Introduction.

The study was performed to assess the acute oral toxicity of the test material in the Sprague-Dawley CD strain rat. The method was designed to meet the requirements of the following:

• OECD Guidelines for Testing of Chemicals No 420 "Acute Oral Toxicity - Fixed Dose

Method" (200 I)

• Method B1 bis Acute Toxicity (Oral) of Commission Directive 2004/73/EC

 

Method.

Following a sighting test at dose levels of 300 mg/kg and 2000 mg/kg, a further group of four fasted females was given a single oral dose of test material, as a solution in dimethyl sulphoxide, 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.

Signs of systemic toxicity noted in animals treated at a dose level of 2000 mg/kg were hunched posture, lethargy, ataxia and pilo-erection. One animal appeared normal on day after dosing and the remaining animals appeared normal two days after dosing.

There were no signs of systemic toxicity noted in the animal treated at a dose level of 300 mg/kg.

 

Bodyweight.

All animals showed expected gains in bodyweight.

 

Necropsy.

No abnormalities were noted at necropsy.

 

Conclusion.

The acute oral median lethal dose (LD₅₀) of the test material in the female Sprague-Dawley CD strain rat was estimated to be greater than 2000 mg/kg bodyweight.

 

Acute Dermal Toxicity

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).

 

 

Justification for selection of acute toxicity – oral endpoint
The available acute oral toxicity study is assigned as reliability study 1 and is the only acute oral toxicity study available.

Justification for selection of acute toxicity – dermal endpoint
The available acute oral toxicity study is assigned as reliability study 1 and is the only acute dermal toxicity study available.

Justification for classification or non-classification

The substance does not meet the criteria for classification, under the CLP regulations, for acute toxicity via the oral route based on the result of an acute oral toxicity study conducted to OECD Guideline 420, giving a LD₅₀ of greater than 2000 mg/kg bodyweight.

The substance does not meet the criteria for classification, under the CLP regulations, for acute toxicity via the dermal route based on the results of an acute dermal toxicity study conducted to OECD Guideline 402, which gave an LD₅₀ of greater than 2000 mg active ingredient/kg bodyweight.