N-tert-butylacrylamide

Endpoint summary

Description of key information

Acute oral toxicity: 

The acute oral toxicity dose (LD50) was considered based on different studies conducted on mice for the given test chemical. The LD50 value is 914 mg/kg bw. The studies concluded that the LD50 value is between 300-2000 mg/kg bw, for acute oral toxicity. Thus, comparing this value with the criteria of CLP regulation, the given test chemical can be classified in “Category 4” for acute oral toxicity.

Acute Inhalation Toxicity:

The acute inhalation toxicity study need not be conducted because exposure to humans via inhalation route is not likely taking into account due to low vapour pressure of the test chemical, which is reported to be 0.385 Pa. Thus, exposure to inhalable dust, mist and vapour of the chemical is highly unlikely. Therefore this study is considered for waiver. 

 

Acute Dermal toxicity:

The acute dermal toxicity dose (LD50) was considered based on study conducted on rats for the test chemical. The study concluded that LD50 value is >2000 mg/kg bw, for acute dermal toxicity. Thus, comparing this value with the criteria of CLP regulation, the given test chemical cannot be classified for acute dermal toxicity.

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from publication

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

The acute toxicity of the test chemical by oral administration in mice was determined according to Weil (1952), using four animals per dosage level and four different doses.

GLP compliance:

not specified

Test type:

other: not specified

Limit test:

no

Species:

mouse

Strain:

other: ddY

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 5-6 weeks
- Weight at study initiation: 29 2.2 g body weight
- Housing: Animals were randomly placed in plastic cages (5-7 per cage) containing wooden flakes.
- Diet (e.g. ad libitum): laboratory chow, ad libitum
- Water (e.g. ad libitum): water, ad libitum

Route of administration:

oral: gavage

Vehicle:

DMSO

Details on oral exposure:

no data

Doses:

5.6 - 9.7 mmol/kg (712.23 - 1233.7 mg/kg bw)

No. of animals per sex per dose:

4 animals per dose

Control animals:

not specified

Details on study design:

no data

Statistics:

The acute toxicity of the test compounds by oral administration in mice was determined according to Weil (1952).

Preliminary study:

no data

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

941.174 mg/kg bw

Based on:

test mat.

95% CL:

712.23 - 1 233.7

Remarks on result:

other: 50% mortality was observed

Mortality:

50% Mortality was observed in treated mice at 941.174 mg/kg bw.

Clinical signs:

other: no data

Gross pathology:

no data

Other findings:

no data

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The lethal concentration (LD50) value for acute oral toxicity test was considered to be 914.174 mg/kg bw, with 95% confidence limit of 712.23 - 1233.7 mg/kg, when male ddy strain mice were treated with the given test chemical orally.

Executive summary:

Acute oral toxicity study was performed by using the given test chemical in Male mice of ddY strain at the dose concentration of 5.6 - 9.7 mmol/kg (712.23 - 1233.7 mg/kg bw). The given test chemical was dissolved in DMSO and administered via oral route. Animals were 5-6 weeks of age and 29 ± 2.2 g body weight at the beginning of the experiment and were randomly placed in plastic cages (5-7 per cage) containing wooden flakes. They were fed laboratory chow and water ad libitum. The acute toxicity of the test compounds by oral administration in mice was determined according to Weil (1952). 50% Mortality was observed in treated mice at 941.174 mg/kg bw. Therefore, the lethal concentration (LD50) value for acute oral toxicity test was considered to be 914.174 mg/kg bw, with 95% confidence limit of 712.23 - 1233.7 mg/kg, when male ddy strain mice were treated with the given test chemical orally.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

941.174 mg/kg bw

Quality of whole database:

Data is Klimisch 2 and from publication

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because exposure of humans via inhalation is not likely taking into account the vapour pressure of the substance and/or the possibility of exposure to aerosols, particles or droplets of an inhalable size

Endpoint conclusion

Quality of whole database:

Waiver

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Data is from experimental study report

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Principles of method if other than guideline:

The objective of the study was to assess the dermal toxicity of test chemical after single dose application by dermal route in rats.

GLP compliance:

yes

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:In-House Bred at sa-Ford, Animal Facility
- Age at study initiation:N/A
- Health Status:Healthy young adult animals were used for the study. Females were nulliparous and non pregnant.
- Weight (Prior to Treatment):Male: Minimum: 226 g and Maximum: 253 g , Female: Minimum: 233 g and Maximum: 244 g
- Fasting period before study:N/A
- Housing:The animals were housed individually in polycarbonate cages.
- Bedding : All cages were provided with corn cobs.
- Room Sanitation : The experimental room floor and work tops were swept and mopped with disinfectant solution every day.
- Cages and water bottle : All the cages and water bottles were changed at least twice every week.
- Diet (e.g. ad libitum):All animals were provided conventional laboratory rodent diet (Nutrivet Life Sciences, Pune) ad libitum.
- Water (e.g. ad libitum):Aqua guard filtered tap water was provided ad libitum via drinking bottles.
- Acclimation period:All animals were acclimatized to the test conditions for 5 days prior to administration of the test item.
- Randomization : Animals were selected manually. No computer generated randomization program was used.

ENVIRONMENTAL CONDITIONS
- Temperature (°C):Minimum: 20.40 °C and Maximum: 23.10 °C
- Humidity (%):Minimum: 38.40% and Maximum: 56.00%
- Air changes (per hr):More than 12 changes per hour
- Photoperiod (hrs dark / hrs light):12:12

Type of coverage:

semiocclusive

Vehicle:

other: distilled water

Details on dermal exposure:

TEST SITE
- Area of exposure:The test item was applied uniformly over clipped dorsal area of rat skin.
- % coverage:Approximately 10% body surface area of rats.
- Type of wrap if used: Test item was held in contact with the skin with a porous gauze dressing and non-irritating tape throughout a 24-hour exposure period. The test site was further covered in a suitable manner to retain the gauze dressing and test item and ensured that the animals cannot ingest the test item.

REMOVAL OF TEST SUBSTANCE
- Washing (if done):The residual test item was removed by using distilled water.
- Time after start of exposure:24-hour.

TEST MATERIAL
- Amount(s) applied (volume or weight with unit):A limit dose of 2000 mg/ kg body weight of test item was applied.
- Constant volume or concentration used: yes
- For solids, paste formed: yes

VEHICLE
- Amount(s) applied (volume or weight with unit):0.2 ml distilled water

Duration of exposure:

24-hour

Doses:

2000 mg/kg body weight.

No. of animals per sex per dose:

10 (Five per sex)

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:Daily
- Necropsy of survivors performed: yes
At the end of 14 day observation period, all the surviving rats were euthanised by overdose of CO2 and subjected to gross pathology examination, for external and internal observations.
- Other examinations performed:
- Clinical signs : After test item administration, individual animals were frequently observed at 1, 2, 3 and 4 hours post dosing on day 0 (day of dosing). Subsequently, all animals were observed once a day during the 14 day observation period.

- Body weight: All rats were weighed on days 0 (prior to dosing), 7 and 14.

other:
- Local Signs/Skin Reactions
All animals were observed once daily during days 1-14 (in common with clinical signs).

- Mortality
Animals were observed twice daily for any mortality during the experimental period.

Statistics:

No statistical analysis was performed since the study was terminated with limit test.

Preliminary study:

No data

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: no mortality was observed

Mortality:

No mortality was observed at limit dose of 2000 mg/kg body weight of test item during the 14 day observation period.

Clinical signs:

other: No systemic or local signs of toxicity were observed at limit dose of 2000 mg/kg body weight of test item during the experimental period, except mild erythema from day 2 to 9 and scab from day 10 to 12 was observed in female animal no. 10

Gross pathology:

The external and internal gross pathological observation of all terminally sacrificed animals did not show any pathological abnormality.

Other findings:

no data

Table 1: Individual Animal Body Weight (g) andBody Weight Changes(%)

 

Dose:2000 mg/ kg bodyweight                                                                                                         

Animal No.	Sex	Body Weight (gram)			Body Weight Change (%)
		Day 0	Day 7	Day 14	Day 0-7	Day 0-14
1	Male	253	239	256	-5.53	1.19
2		246	238	276	-3.25	12.20
3		238	227	238	-4.62	0.00
4		226	217	221	-3.98	-2.21
5		247	238	255	-3.64	3.24
6	Female	233	226	227	-3.00	-2.58
7		244	246	247	0.82	1.23
8		242	234	243	-3.31	0.41
9		243	240	229	-1.23	-5.76
10		242	235	244	-2.89	0.83

Table 2: Individual Animal Clinical Signs and Symptoms

 

Dose:2000 mg/kg body weight

Animal No.	Sex	Hour(s) - Day 0				Day
		1	2	3	4	1	2	3	4	5	6	7	8	9	10	11	12	13	14
1	Male	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
2		1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
3		1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
4		1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
5		1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
6	Female	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
7		1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
8		1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
9		1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1
10		1	1	1	1	1	65^+	65^+	65^+	65^+	65^+	65^+	65^+	65^+	146	146	146	1	1

Keys: 1 = Normal, 65 = Erytema, 146 = Scab, + = Mild

Table 3: Individual Animal Mortality Record

 

Dose:2000 mg/kg body weight

Animal No.	Sex	Days of Observation (0 to 14)
		Morning Observations	Evening Observations
1	Male	No mortality and morbidity	No mortality and morbidity
2		No mortality and morbidity	No mortality and morbidity
3		No mortality and morbidity	No mortality and morbidity
4		No mortality and morbidity	No mortality and morbidity
5		No mortality and morbidity	No mortality and morbidity
6	Female	No mortality and morbidity	No mortality and morbidity
7		No mortality and morbidity	No mortality and morbidity
8		No mortality and morbidity	No mortality and morbidity
9		No mortality and morbidity	No mortality and morbidity
10		No mortality and morbidity	No mortality and morbidity

 

Interpretation of results:

other: not classified

Conclusions:

Under the condition of the study, the LD50 value was considered to be >2000 mg/kg bw, when groups of 5 male and female wistar rats were semiocclusively treated with test chemical by dermal application following 14 days of observation period according to OECD Guideline 402 (Acute Dermal Toxicity).

Executive summary:

The acute dermal toxicity study was done by using the given test chemical according to OECD Guideline 402 (Acute Dermal Toxicity) in groups of 5 male and female wistar rats at dose concentration of 2000 mg/kg bw. Distilled water was used as vehicle. Five male and five female healthy young adult rats were randomly selected and used for conducting acute dermal toxicity study. Rats free from injury and irritation of skin were selected for the study. Twenty four hours prior to dermal application of test item, approximately 10% of body surface area of each rat was clipped. A limit dose of 2000 mg/ kg body weight of test item moistened with 0.2 ml distilled water was applied by single dermal application and observed for 14 days after treatment. On test day 0, an amount of test item moistened with 0.2 ml distilled water was applied directly on the intact skin of clipped area of rats; the surgical gauze patch was put on to the intact skin of clipped area. This gauze patch was covered with a non-irritating adhesive tape. The dressing was wrapped around the abdomen and anchored with non-irritating adhesive tape. After the 24-hour application period, the dressings were removed and theskin was gently wiped with distilled water. The skin reactions were assessed. The animals were observed daily for mortality and clinical signs, during the acclimatization period. All animals were observed for clinical signs at approximately 1, 2, 3 and 4 hours after treatment on day 0 and once daily during test days 1‑14. Mortality was recorded after application on test day 0 and twice daily during days 1-14 (at least once on the day of sacrifice). Local signs / Skin reactions were observed daily from test days 1-14 (in common with clinical signs). Body weights were re­corded on day 0 (prior to application) and on day 7 and 14. All animals were necropsied and examined macroscopically. No mortality was observed in any animal till the end of the experimental period. No systemic or local signs of toxicity were observed at limit dose of 2000 mg/kg body weight of test item during the experimental period, except mild erythema from day 2 to 9 and scab from day 10 to 12 was observed in female animal no. 10. There was declined mean body weight gain of male (on day 7) and female animals (on day 7 and 14) was observed as compared to day 0, whereas only male animals were observed with body weight gain on day 14 as compared to day 0. The external and internal gross pathological observation of all terminally sacrificed animals did not show any pathological abnormality.

Under the condition of the study, the LD50 value was considered to be >2000 mg/kg bw, when groups of 5 male and female wistar rats were semiocclusively treated with test chemical by dermal application following 14 days of observation period according to OECD Guideline 402 (Acute Dermal Toxicity).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

Data is Klimisch 1 and from experimental study report

Additional information

Acute oral toxicity:

In different studies, the given test chemical has been investigated for acute oral toxicity to a greater or lesser extent. Often are the studies based on in-vivo experiments in rodents, i.e. most commonly in mice for the given test chemical. The studies are summarized as below –

 

The reported study was mentioned in publication, handbook and different authoritative databases and conducted to assess the toxicological profile of the test chemical in Male mice of ddY strain at the dose concentration of 5.6 - 9.7 mmol/kg (712.23 - 1233.7 mg/kg bw). The given test chemical was dissolved in DMSO and administered via oral route. Animals were 5-6 weeks of age and 29 ± 2.2 g body weight at the beginning of the experiment and were randomly placed in plastic cages (5-7 per cage) containing wooden flakes. They were fed laboratory chow and water ad libitum. The acute toxicity of the test compounds by oral administration in mice was determined according to Weil (1952). 50% Mortality was observed in treated mice at 941.174 mg/kg bw. Therefore, the lethal concentration (LD50) value for acute oral toxicity test was considered to be 914.174 mg/kg bw, with 95% confidence limit of 712.23 - 1233.7 mg/kg, when male ddy strain mice were treated with the given test chemical orally.

 

The above study is supported with another study mentioned in publication and authoritative database for the given test chemical. The acute oral toxicity study was performed in 4 male ddy strain mice at dose concentration of 568.2-1686.3 mg/kg bw. DMSO was used as vehicle. 50% mortality was observed at dose 1209 mg/kg bw with the 95% confidence limit of 568.2-1686.3 mg/kg bw. Hence, the LD50 value was considered to be 1209 mg/kg bw, when mice were treated with test chemical orally.

 

This study is supported with the data available in publication and authoritative database for the given test chemical. The acute oral toxicity study was performed in 4 male ddy strain mice at dose concentration of 333-672 .33 mg/kg bw.0.9% saline was used as vehicle. 50% mortality was observed at dose 477 mg/kg bw(95% confidence limit:333-672.33 mg/kg bw).Hence,LD50 value was considered to be 477 mg/kg bw, when mice were treated with test chemical orally.

 

These studies are further supported with the data available in publication and authoritative database for the given test chemical. The acute oral toxicity study was performed in 4 male ddy strain mice at dose concentration of 226.31-599.74 mg/kg bw. 0.9% saline was used as vehicle. 50% mortality was observed at dose 419 (95% confidence limit: 226.31-599.74 mg/kg bw).Hence, the LD50 value was considered to be 419 mg/kg bw, when mice were treated with test chemical orally.

 

Thus, based on the above summarised studies on test chemical, it can be concluded that LD50 value is between 300-2000 mg/kg bw, for acute oral toxicity. Thus, comparing this value with the criteria of CLP regulation, the given test chemical can be classified in “Category 4” for acute oral toxicity.

 

Acute Inhalation Toxicity:

The acute inhalation toxicity study need not be conducted because exposure to humans via inhalation route is not likely taking into account due to low vapour pressure of the test chemical, which is reported to be 0.385 Pa. Thus, exposure to inhalable dust, mist and vapour of the chemical is highly unlikely. Therefore this study is considered for waiver. 

 

Acute Dermal Toxicity:

The acute dermal toxicity study was done by using the given test chemical according to OECD Guideline 402 (Acute Dermal Toxicity) in groups of 5 male and female wistar rats at dose concentration of 2000 mg/kg bw. Distilled water was used as vehicle. Five male and five female healthy young adult rats were randomly selected and used for conducting acute dermal toxicity study. Rats free from injury and irritation of skin were selected for the study. Twenty four hours prior to dermal application of test item, approximately 10% of body surface area of each rat was clipped. A limit dose of 2000 mg/ kg body weight of test item moistened with 0.2 ml distilled water was applied by single dermal application and observed for 14 days after treatment. On test day 0, an amount of test item moistened with 0.2 ml distilled water was applied directly on the intact skin of clipped area of rats; the surgical gauze patch was put on to the intact skin of clipped area. This gauze patch was covered with a non-irritating adhesive tape. The dressing was wrapped around the abdomen and anchored with non-irritating adhesive tape. After the 24-hour application period, the dressings were removed and the skin was gently wiped with distilled water. The skin reactions were assessed. The animals were observed daily for mortality and clinical signs, during the acclimatization period. All animals were observed for clinical signs at approximately 1, 2, 3 and 4 hours after treatment on day 0 and once daily during test days 1‑14. Mortality was recorded after application on test day 0 and twice daily during days 1-14 (at least once on the day of sacrifice). Local signs / Skin reactions were observed daily from test days 1-14 (in common with clinical signs). Body weights were re­corded on day 0 (prior to application) and on day 7 and 14. All animals were necropsied and examined macroscopically. No mortality was observed in any animal till the end of the experimental period. No systemic or local signs of toxicity were observed at limit dose of 2000 mg/kg body weight of test item during the experimental period, except mild erythema from day 2 to 9 and scab from day 10 to 12 was observed in female animal no. 10. There was declined mean body weight gain of male (on day 7) and female animals (on day 7 and 14) was observed as compared to day 0, whereas only male animals were observed with body weight gain on day 14 as compared to day 0. The external and internal gross pathological observation of all terminally sacrificed animals did not show any pathological abnormality.

Under the condition of the study, the LD50 value was considered to be >2000 mg/kg bw, when groups of 5 male and female wistar rats were semiocclusively treated with test chemical by dermal application following 14 days of observation period according to OECD Guideline 402 (Acute Dermal Toxicity).

 

Justification for classification or non-classification

Based on the above studies for the test chemical, it can be concluded that LD50 value is between 300-2000 mg/kg bw, for acute oral toxicity and LD50 value is >2000 mg/kg bw, for acute dermal toxicity. Thus, comparing these range and value with the criteria of CLP regulation, the given test chemical can be classified in “Category 4” for acute oral toxicity and cannot be classified for acute dermal toxicity. For acute inhalation toxicity wavier was added so, not possible to classify.