1-butylpyrrolidin-2-one

Endpoint summary

Description of key information

- Acute oral toxicity: LD50 of 300-2000 mg/kg bw (OECD 423; Wistar rats; clinical signs, deaths, no effects on body weights and no findings at necropsy).

- Acute inhalation toxicity: LC50 > 5.1 mg/L (OECD 403, EPA OPPTS Guideline 870.1300; Crl:CD(SD) rats; no death, clinical signs included laboured respiration, ataxia, prostratio, hypoactivity, clonic convulsions, body cool to touch, red material around the nose, partial closure of the eye(s) unkempt appearance, impaired equilibrium and decreased defecation and urination)
- Acute dermal toxicity: LD50 > 2000 mg/kg bw (OECD 402; Wistar rats; no effects).

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:

2011-09-15 to 2011-10-18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Commission Regulation (EC) No 440/2008

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

other: RccHan: WIST(SPF)

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories B.V., Horst, The Netherlands.
- Age at study initiation: 10 weeks (when treated).
- Weight at study initiation: 172.2 g - 188.7 g (when treated).
- Fasting period before study: yes, overnight prior to treatment (18 to 19 hours) and approximately 3 - 4 hours post dose.
- Housing: In groups of three in Makrolon type-4 cages with wire mesh tops and standard softwood bedding ("Lignocel" J. Rettenmaier & Söhne GmbH CoKG, 73494 Rosenberg / Germany, imported by Provimi Kliba SA, 4303 Kaiseraugst / Switzerland) including paper enrichment Enviro Dri (Lillico) (batch no. 75).
- Diet (e.g. ad libitum): Pelleted standard Provimi Kliba 3433 rat/mouse maintenance diet, batch no. 44/11 (Provimi Kliba AG, 4303 Kaiseraugst / Switzerland) ad libitum (except for the overnight fasting period prior to treatment and approximately 3 - 4 hours post dose).
- Water (e.g. ad libitum): Community tap-water from Itingen was available ad libitum in water bottles.
- Acclimation period: 5 days; under laboratory conditions, after health examination. Only animals without any visible signs of illness were used for the study.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 30-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES:
From: 2011-09-15 To: 2011-09-20 (group 1: the 2000 mg/kg bw dose group);
From: 2011-09-22 To: 2011-10-06 (group 2: the 300 mg/kg bw dose group);
From: 2011-10-04 To: 2011-10-18 (group 3: the 300 mg/kg bw dose group).

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 0.2 g/mL and 0.03 g/mL.
- Amount of vehicle (if gavage): 10 mL/kg body weight.
- Justification for choice of vehicle: A 20% (weight/weight) mixture with bi-distilled water formed a clear solution suitable for oral gavage application.
- Purity: bi-distilled water

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg body weight.

DOSAGE PREPARATION:
The dose formulations were prepared shortly before each dosing occasion using a magnetic stirrer.
The test item was weighed into a tared glass beaker on a suitable precision balance and the vehicle added (weight : volume).
Homogeneity of the test item in the vehicle was maintained until and during administration using a magnetic stirrer.

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: not reported

Doses:

single doses of 300 and 2000 mg/kg bw

No. of animals per sex per dose:

3

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 viability, mortality and clinical signs (daily during the acclimatization period and at approximately 30 minutes and 1, 2, 3 and 5 hours after administration on test day 1 (in common with the clinical signs) and twice daily during days 2 - 15).
Body weight were recorded on test days 1 (prior to administration), 8 and 15.
- Necropsy of survivors performed: yes
All animals which died spontaneously during the observation period were necropsied. All surviving animals were killed at the end of the observation period by carbon dioxide asphyxiation and discarded after macroscopic examinations were performed. An external examination and opening of the abdominal and thoracic cavities for examinations of major organs were performed. The appearance of any macroscopic abnormalities was recorded. No organs or tissues were retained.
- Other examinations performed: clinical signs, body weight.

Statistics:

No statistical analysis was used.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 300 - < 2 000 mg/kg bw

Based on:

act. ingr.

Mortality:

All six animals treated with 300 mg/kg of N-Butylpyrrolidone survived until the end of the study period. Two females treated with 2000 mg/kg of the test item died after the administration and one of them was sacrificed in extremis also on the day of treatment.

Clinical signs:

other: The females treated with 2000 mg/kg showed shortly after treatment moderate convulsions, tachypnea, prostration, clear lacrimation in both eyes and were found unconscious and two of them were found dead after treatment. The females treated with 300 mg/kg

Gross pathology:

No macroscopic findings were recorded at necropsy.

Other findings:

No other findings were observed.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The median lethal dose of N-Butylpyrrolidone after single oral administration to female rats, observed over a period of 14 days is: 300 mg/kg body weight

Executive summary:

The study was conducted to assess the acute toxicity of N-Butylpyrrolidone in rats. Three female RccHan: WIST (SPF) rats, were treated with N-Butylpyrrolidone by oral gavage administration at a dosage of 2000 mg/kg body weight and two further groups of three females each were treated with 300 mg/kg body weight of the test item. The test item was formulated in purified water at a concentration of 0.2 g/mL and 0.03 g/mL and administered at a dosing volume of 10 mL/kg. The animals were examined daily during the acclimatization period and mortality, viability and clinical signs were recorded. All animals were examined for clinical signs approximately 30 minutes after treatment and again at approximately 1, 2, 3 and 5 hours after treatment on day 1 and once daily during test days 2 - 15. Mortality and viability was recorded together with clinical signs and twice daily during days 2 - 15. Body weights were recorded on day 1 (prior to administration) and on days 8 and 15. All animals were necropsied and examined macroscopically. All six animals treated with 300 mg/kg of N-Butylpyrrolidone survived until the end of the study period. Two females treated with 2000 mg/kg of the test item died after the administration and one of them was sacrificed in extremis also on the day of treatment. The females treated with 2000 mg/kg showed shortly after treatment moderate convulsions, tachypnea, prostration, clear lacrimation in both eyes and were found unconscious and two of them were found dead later. The females treated with 300 mg/kg of the test item had a slight to moderately decreased activity and slightly ruffled fur. The three further females treated with 300 mg/kg had no clinical signs. No clinical signs were observed during days two to 15. The body weight of the animals was within the range commonly recorded for this strain and age. No macroscopic findings were recorded at necropsy. The median lethal dose of N-Butylpyrrolidone after single oral administration to female rats, observed over a period of 14 days is: 300 mg/kg body weight < LD50 (female rat) < 2000 mg/kg body weight.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

300 mg/kg bw

Quality of whole database:

GLP guideline study

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental starting date:2017-02-08 - 2017-02-28 (gross necropsy) - 2017-04-28 (Issue of Final report)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

The initial target exposure level was slightly greater than the regulatory limit study concentration of 5 mg/L for aerosols (approximately 5.2 mg/L). Since there was no mortality observed at the limit test, additional exposure levels were not required.

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

traditional method

Limit test:

yes

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

Animal Receipt and Acclimation
The Crl:CD(SD) rats used for this study were received in good health from Charles River Raleigh on 07 Feb 2017. Each animal was inspected by a qualified technician upon receipt. The rats were uniquely identified by ear tags displaying the animal numbers and were acclimated to the laboratory for a minimum of 6 days. During the acclimation period, the rats were observed twice daily for mortality and moribundity. The animals were subjected to restraint in the nose only exposure holding tubes for 1 hour on 13 Feb 2017 prior to test substance exposure. Following the restraint period, each animal was observed and there were no clinical signs of injury or stress. Animals were held in restraint tubes for 20 minutes prior to initiation of exposure after they were delivered to the exposure room.

Animal Housing
Upon arrival, all animals were housed individually in suspended wire-mesh cages. Caging was cleaned at appropriate intervals. The animals were maintained in accordance with Charles River Ashland SOPs and the Guide for the Care and Use of Laboratory Animals (National Research Council, 2011). On the day of exposure, the animals were placed in nose only exposure holding tubes in the animal room, transported to the exposure room, exposed for the requisite duration, and then returned to their home cages.

Diet, Drinking Water, and Maintenance
The basal diet used in this study, PMI Nutrition International, LLC, Certified Rodent LabDiet® 5002 (block), is a certified feed with appropriate analyses performed by the manufacturer and provided to Charles River Ashland. Reverse osmosis-treated water supplying the facility is analyzed for contaminants according to Charles River Ashland SOPs. Filters servicing the automatic watering system are changed regularly according to Charles River Ashland SOPs. The results of the diet and water analyses are retained with the Charles River Ashland facility data. No contaminants were present in animal feed or water at concentrations sufficient to interfere with the objectives of this study. The basal diet and reverse osmosis-treated water, delivered by an automatic watering system, were provided ad libitum, except during acclimation to the nose only restraint and during the exposure period. Water bottles were provided as appropriate following exposure.

Environmental Conditions
The animal room was maintained with controlled temperature, humidity, and fluorescent lighting (12 hours light/12 hours dark). The light status (on or off) was recorded once every 15 minutes. The room temperature and humidity controls were set to maintain conditions of 73°F ± 5°F (approximately 23°C ± 3°C) and 50% ± 20% relative humidity. Room temperature and relative humidity were monitored continuously using the Metasys DDC Electronic Environmental control system and were scheduled for data collection on an hourly basis. Actual mean daily temperature ranged from 72.5°F to 73.2°F (22.5°C to 22.9°C) and mean daily relative humidity ranged from 40.9% to 48.0% during the study. Air handling units were set to provide a minimum of 10 fresh air changes per hour, 100% fresh air.

Enrichment
Each animal was provided devices for environmental enrichment and to aid in maintaining the animals’ oral health (starting during acclimation). Enrichment devices were not available during the restraint acclimation and the exposure period and were sanitized approximately weekly. Additional enrichment was provided following acclimation to nose only exposure restraint tubes.

Assignment of Animals to Treatment Groups
Animals used in the study were selected from available stock and were arbitrarily assigned to an exposure group based on age and body weight requirements and on the appearance of general good health. The selected animals were approximately 8 weeks old at initiation of exposure; body weight values ranged from 261 g to 272 g for males and from 200 g to 207 g for females. Individual body weights at assignment were within ca. 20% of the mean for each sex.

Route of administration:

inhalation: vapour

Type of inhalation exposure:

nose only

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

2.4 µm

Geometric standard deviation (GSD):

1.67

Remark on MMAD/GSD:

N = 2

Details on inhalation exposure:

Temperature (°C): 22
Standard Deviation: 0.5
Relative Humidity (%): 23
Standard Deviation: 2.6
Airflow Rate (LPM): 33.5
Standard Deviation: 0.30
N = 4
In order to achieve the target concentration, additional humidified air was not added to the exposure system, resulting in a relative humidity for the test substance atmosphere which was less than the protocol-specified minimum of 30%. Low humidity for a liquid aerosol atmosphere is considered acceptable for a single 4-hour exposure and does not adversely affect the results or interpretation of the data.

Nominal Exposure Concentration:
Test substance used: 48.2 g; Exposure Time: 240 min; Nominal Concentraiton 6.0 mg/L)
Actual Exposure Concentration:
Target concentration: 5.2 mg/L, Mean actual concentration: 5.1 mg/L, Standard Deviation: 0.22, N = 8

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

5.1 mg/L

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observed for mortality twice daily, observed for clinical signs once during exposure, after the 4-hour exposure, 1 - 2 hours post exposure and once daily for 14 days following exposure, body weight were obtained on Study Days 0, 1, 3, 7, and 14.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.1 mg/L air (nominal)

Mortality:

None of the animals died during exposure or during the 14-day post-exposure observation period.

Clinical signs:

other: The only clinical observation noted during exposure was labored respiration for 1 female. Clinical observations following exposure consisted of ataxia (this incidence was reduced at the next observation period and was not observed thereafter), prostration

Body weight:

All animals lost weight from Study Day 0 to Study Day 1 (5 g to 29 g). All animals surpassed their initial (Study Day 0) body weight by Study Day 14 and were considered normal.

Gross pathology:

The only macroscopic finding noted at the scheduled necropsy was clear fluid content in the uterus for 1 female.

Text Table 8
Clinical Observations following Exposure
Clinical Observation	Group (mg/L) 5.1
	M	F
Ataxia	5	2
Prostration	0	3
Hypoactivity	1	0
Clonic Convulsions	0	2
Body Cool to Touch	0	2
Labored Respiration	0	1
Decreased Respiration	3	4
Partial Closure Left Eye	1	3
Partial Closure Right Eye	1	3
Wet Red Material Around Nose	1	1

Text Table 9
Clinical Observations 1-2 Hours Post-Exposure
Clinical Observation	Group (mg/L) 5.1
	M	F
Ataxia	3	1
Unkempt Appearance	1	0
Hypoactivity	0	1
Impaired Equilibrium	0	2
Prostration	0	3
Labored Respiration	0	1
Partial Closure Left Eye	1	3
Partial Closure Right Eye	1	3
Dried Red Material Around Nose	1	0

Text Table 10
Clinical Observations during the 14-Day Post-Exposure Period
Clinical Observation	Group (mg/L) 5.1
	M	F
Unkempt Appearance	0/0	2/2
Defecation Decreased	1/1	3/3
Urination Decreased	0/0	1/1
Small Feces	0/0	2/1
Dried Clear Material Ventral Neck	0/0	2/2
Dried Clear Material Ventral Trunk	0/0	3/3
Dried Clear Material Urogenital Area	0/0	1/1
Wet Yellow Material Urogenital Area	0/0	1/1
Dried Red Material Around Nose	0/0	2/2

Interpretation of results:

GHS criteria not met

Conclusions:

The LC50 of the test substance was > 5.1 mg/L when male and female Crl:CD(SD) rats were exposed to an aerosol of the test substance as a single, 4-hour, nose only exposure.

Executive summary:

The objective of this study was to determine the acute inhalation toxicity of the test substance when administered as a single, 4-hour, nose only inhalation exposure to rats. The protocol was designed in accordance with the US EPA OPPTS Guideline 870.1300, Acute Inhalation Toxicity, August, 1998 and the OECD Guidelines for the Testing of Chemicals, Section 403, Acute Inhalation Toxicity, September, 2009. The test substance was administered to 1 group of 5 male and 5 female Crl:CD(SD) rats via nose only inhalation exposure as a liquid droplet aerosol at a concentration of 5.1 mg/L. The aerosol exposure atmosphere was characterized by a mean particle size of 2.4 ± 1.67 μm (MMAD ± GSD). Mortality, clinical observations, body weights, and body weight changes were evaluated over a 14-day post-exposure observation period. Necropsies were conducted on all animals.

None of the animals died during the study. The only clinical observation noted during exposure was labored respiration for 1 female. Clinical observations following exposure consisted of ataxia, prostration, hypoactivity, clonic convulsions, body cool to touch, laboured and decreased respiration, partial closure of the eye(s), and red material around nose. Clinical observations at the 1 to 2 hour post-exposure observation period consisted of ataxia, hypoactivity, unkempt appearance, impaired equilibrium, prostration, labored respiration, partial closure of the eye(s), and red material around nose.

Clinical observations during the 14-day post-exposure observation period consisted of unkempt appearance, defecation and urination decreased, small feces, red material around nose, yellow material urogenital area, and clear material neck, trunk, and urogenital area. All animals were considered clinically normal by Study Day 4. All animals lost weight from Study Day 0 to Study Day 1. All animals surpassed their initial (Study Day 0) body weight by Study Day 14. The only macroscopic finding noted at the scheduled necropsy was clear fluid content in the uterus for 1 female.

Based on the results of this study, the LC50 of the test substance was > 5.1 mg/L when male and female Crl:CD(SD) rats were exposed to an aerosol of the test substance as a single, 4-hour, nose only exposure.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

5 100 mg/m³ air

Quality of whole database:

GLP guideline study

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:

Experimental Starting Date: 29 May 2014; Experimental Completion Date: 19 June 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study.

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

GLP compliance:

yes (incl. QA statement)

Remarks:

UK GLP standards (Schedule 1, Good Laboratory Practice Regulations 1999 (SI 1999/3106 as amended by SI 2004/0994)). The Department of Health of the Government of the United Kingdom.

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
- Wistar (RccHan™:WIST) strain rats
- Source: Harlan Laboratories UK Ltd., Oxon, UK.
- Age at study initiation: eight to twelve weeks
- Weight at study initiation: at least 200 g
- Fasting period before study: no
- Housing: individually during the 24-hour exposure period and in groups of up to four, by sex, for the remainder of the study.
- Diet (e.g. ad libitum): ad libitum (2014C Teklad Global Rodent diet supplied by Harlan Laboratories UK Ltd., Oxon, UK).
- Water (e.g. ad libitum): ad libitum (tap water)
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 25
- Humidity (%): 30 to 70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: the back and flanks (shorn skin)
- % coverage: 10 % of of the total body surface area
- Type of wrap if used: A piece of surgical gauze was placed over the treatment area and semi occluded with a piece of self adhesive bandage

REMOVAL OF TEST SUBSTANCE
- Washing (if done): wiped with cotton wool moistened with distilled water to remove any residual test item
- Time after start of exposure: 24 hours

TEST MATERIAL
For the purpose of the study the test item was used as supplied. The specific gravity was determined and used to calculate the appropriate dose volume for the required dose level. Specific gravity was 0.952
- Amount(s) applied (volume or weight with unit): 2.11 mL/kg
- Constant volume used: yes

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

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 0.5, 1, 2 and 4 hours after dosing and subsequently once daily for fourteen days. Individual body weights were recorded prior to application of the test item on Day 0 and on Days 7 and 14.
- Necropsy of survivors performed: yes. 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.
- Other examinations performed: 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 following scale:
Erythema and Eschar Formation:
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.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: no effects

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.

Dermal Reactions

Very slight erythema was noted at the test sites of two females. Small superficial scattered scabs and glossy skin were also noted at the test site of one of these females. No signs of dermal irritation were noted at the test sites of all males and three females.

Table 1. Individual dermal reactions (males)

Dose Level mg/kg	Animal Number and Sex	Observation	Effects Noted After Initiation of Exposure (Days)
			1	2	3	4	5	6		8	9	10	11	12	13	14
	1-0 Male	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-0 Male	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-1 Male	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
2000		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-2 Male	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-3 Male	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0

Table 2. Individual dermal reactions (females)

Dose Level mg/kg	Animal Number and Sex	Observation	Effects Noted After Initiation of Exposure (Days)
			1	2		4	5	6		8	9	10	11	12	13	14
	2-0 Female	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	4-0 Female	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	4-1 Female	Erythema					0	0	0	0	0	0	0	0	0	0
2000		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	SsG	SsG	SsG	0	0	0	0	0	0	0	0
	4-2 Female	Erythema	1	0	0	0	0	0	0	0	0	0	0	0	0	0
		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	4-3 Female	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0

0 - No reactions;

Ss - Small superficial scattered scabs;

G - Glossy skin

Table 3. Individual Body Weights and Body Weights Changes

Dose Level (mg/kg bw)	Animal Number and Sex	Body Weight (g) at Day			Body Weight Change (g) during Week
		0	7	14	1	2
2000	1-0 Male	229	245	263	16	18
	3-0 Male	266	270	301	4	31
	3-1 Male	257	272	298	15	26
	3-2 Male	241	250	282	9	32
	3-3 Male	264	285	306	21	21
	2-0 Female	216	221	234	5	13
	4-1 Female	233	230	243	-3	13
	4-2 Female	218	218	230	0	12
	4-3 Female	214	220	227	6	7
	4-4 Female	226	227	244	1	17

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 2000 mg/kg body weight.
The test item does not meet the criteria for classification according to the Globally Harmonized System of Classification and Labelling of Chemicals.

Executive summary:

The study was performed to assess the acute dermal toxicity of the test item in the Wistar strain rat. Initially, two animals (one male and one female) were given a single, 24 hour, semi-occluded dermal application of the undiluted test item to intact skin at a dose level of 2000 mg/kg body weight. Based on the results of the initial test, a further group of eight animals (four males and four females) was similarly treated. Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy.

There were no deaths and no signs of systemic toxicity in treated animals. Very slight erythema was noted at the test sites of two females. Small superficial scattered scabs and glossy skin were also noted at the test site of one female. No other signs of dermal irritation were noted. Animals showed expected gains in body weight except for two females which showed no gain in body weight or body weight loss during the first week with expected gain in body weight during the second week. No abnormalities were noted at necropsy. 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. The test item does not meet the criteria for classification according to the Globally Harmonized System of Classification and Labelling of Chemicals.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

GLP guideline study

Additional information

Acute oral toxicity

The study was conducted to assess the acute toxicity of N-Butylpyrrolidone in rats according to OECD 423 Guideline (Harlan Laboratories, 2013; Report No. D41574). Three female RccHan: WIST (SPF) rats, were treated with N-Butylpyrrolidone by oral gavage administration at a dosage of 2000 mg/kg body weight and two further groups of three females each were treated with 300 mg/kg body weight of the test item. The test item was formulated in purified water at a concentration of 0.2 g/mL and 0.03 g/mL and administered at a dosing volume of 10 mL/kg. The animals were examined daily during the acclimatization period and mortality, viability and clinical signs were recorded. All animals were examined for clinical signs approximately 30 minutes after treatment and again at approximately 1, 2, 3 and 5 hours after treatment on day 1 and once daily during test days 2 - 15. Mortality and viability was recorded together with clinical signs and twice daily during days 2 - 15. Body weights were recorded on day 1 (prior to administration) and on days 8 and 15. All animals were necropsied and examined macroscopically. All six animals treated with 300 mg/kg of N-Butylpyrrolidone survived until the end of the study period. Two females treated with 2000 mg/kg of the test item died after the administration and one of them was sacrificed in extremis also on the day of treatment. The females treated with 2000 mg/kg showed shortly after treatment moderate convulsions, tachypnea, prostration, clear lacrimation in both eyes and were found unconscious and two of them were found dead later. The females treated with 300 mg/kg of the test item had slightly to moderately decreased activity and slightly ruffled fur. The three further females treated with 300 mg/kg had no clinical signs. No clinical signs were observed during days two to 15. The body weight of the animals was within the range commonly recorded for this strain and age. No macroscopic findings were recorded at necropsy. The median lethal dose of N-Butylpyrrolidone after single oral administration to female rats, observed over a period of 14 days is: 300 mg/kg body weight < LD50 (female rat) < 2000 mg/kg body weight.

Acute inhalation toxicity:

The study was conducted to determine the acute inhalation toxicity of the test substance when administered as a single, 4-hour, nose only inhalation exposure to rats. The protocol was designed in accordance with the US EPA OPPTS Guideline 870.1300, Acute Inhalation Toxicity, August, 1998 and the OECD Guidelines for the Testing of Chemicals, Section 403, Acute Inhalation Toxicity, September, 2009. The test substance was administered to 1 group of 5 male and 5 female Crl:CD(SD) rats via nose only inhalation exposure as a liquid droplet aerosol at a concentration of 5.1 mg/L. The aerosol exposure atmosphere was characterized by a mean particle size of 2.4 ± 1.67 μm (MMAD ± GSD). Mortality, clinical observations, body weights, and body weight changes were evaluated over a 14-day post-exposure observation period. Necropsies were conducted on all animals. None of the animals died during the study. The only clinical observation noted during exposure was labored respiration for 1 female. Clinical observations following exposure consisted of ataxia, prostration, hypoactivity, clonic convulsions, body cool to touch, labored and decreased respiration, partial closure of the eye(s), and red material around nose. Clinical observations at the 1 to 2 hour post-exposure observation period consisted of ataxia, hypoactivity, unkempt appearance, impaired equilibrium, prostration, labored respiration, partial closure of the eye(s), and red material around nose. Clinical observations during the 14-day post-exposure observation period consisted of unkempt appearance, defecation and urination decreased, small feces, red material around nose, yellow material urogenital area, and clear material neck, trunk, and urogenital area. All animals were considered clinically normal by Study Day 4. All animals lost weight from Study Day 0 to Study Day 1. All animals surpassed their initial (Study Day 0) body weight by Study Day 14. The only macroscopic finding noted at the scheduled necropsy was clear fluid content in the uterus for 1 female.

Based on the results of this study, the LC50 of the test substance was > 5.1 mg/L when male and female Crl:CD(SD) rats were exposed to an aerosol of the test substance as a single, 4-hour, nose only exposure.

Acute dermal toxicity

The study was performed to assess the acute dermal toxicity of the test item in the Wistar strain rat (Harlan Laboratories, 2014a; Report No. 41401170). Initially, two animals (one male and one female) were given a single, 24 hour, semi-occluded dermal application of the undiluted test item to intact skin at a dose level of 2000 mg/kg body weight. Based on the results of the initial test, a further group of eight animals (four males and four females) was similarly treated. Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy.

There were no deaths and no signs of systemic toxicity in treated animals. Very slight erythema was noted at the test sites of two females. Small superficial scattered scabs and glossy skin were also noted at the test site of one female. No other signs of dermal irritation were noted. Animals showed expected gains in body weight except for two females which showed no gain in body weight or body weight loss during the first week with expected gain in body weight during the second week. No abnormalities were noted at necropsy. 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. The test item does not meet the criteria for classification according to the Globally Harmonized System of Classification and Labelling of Chemicals.

Justification for classification or non-classification

N-Butylpyrrolidone produced clinical signs and deaths of two female rats treated with 2000 mg/kg bw in the oral acute toxicity study. The median lethal dose was: 300 mg/kg bw < LD50 (female rat) < 2000 mg/kg bw. Therefore, the substance meets the criteria for classification and labelling for oral toxicity (Cat 4, H302: Harmful if swallowed) in accordance with European Regulation (EC) No. 1272/2008.

N-Butylpyrrolidone did not produce mortality, only transient clinical effects, and only one macroscpic finding (clear fluid content in the uterus) in 1 female in the acute inhalation toxicity study. the LC50 was greater than 5.1 mg/L, correspoding to 5100 mg/m³. Therefore, the substance does not meet the criteria for classification and labelling for inhalation toxicity in accordance with Regulation (EC) No 1272/2008.

N-Butylpyrrolidone did not produced mortality, clinical signs, affected body weights or findings at necropsy in the acute dermal toxicity study. LD50 was greater than 2000 mg/kg bw. No dermal irritation was observed. Therefore the substance does not meet the criteria for classification and labelling for dermal toxicity in accordance with Regulation (EC) No 1272/2008.