2-methyl-3-butenenitrile

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Not stated

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to OECD 401. Study performed before GLP statement. Substance purity and composition are not stated.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

Principles of method if other than guideline:

Not applicable.

GLP compliance:

no

Remarks:

study performed before GLP statement.

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-methyl-3-butenenitrile

EC Number:

240-596-1

EC Name:

2-methyl-3-butenenitrile

Cas Number:

16529-56-9

Molecular formula:

C5H7N

IUPAC Name:

2-methylbut-3-enenitrile

Details on test material:

- Name of test material (as cited in study report): 2-methyl 3 butenenitrile (2M3BN)
- Substance type: no data
- Physical state: colorless liquid
- Impurities (identity and concentrations): no data
- Composition of test material, percentage of components: no data
- Isomers composition: no data
- Purity test date: no data
- Expiration date of the lot/batch: no data
- Stability under test conditions: no data
- Storage condition of test material: no data
- Other: no additional data

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: IFFRA CREDO
- Age at study initiation: no data
- Weight at study initiation: between 150 and 230 g
- Fasting period before study: no data
- Housing: in cage of 37.5 x 23.5 x 16 cm, 2 or 5 rats per cage, with a dusted and sterilized and sawdust litter
- Diet (e.g. ad libitum): IFFARAT food ad libitum
- Water (e.g. ad libitum): ad libitum except a 17/18 hours diet before treatment
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22° ± 1°C
- Humidity (%): 50 ± 10%
- Air changes (per hr): 8 per hour
- Photoperiod (hrs dark / hrs light): no data


IN-LIFE DATES: no data

Administration / exposure

Route of administration:

oral: unspecified

Vehicle:

other: aqueous dispersion of arabic gum

Details on oral exposure:

VEHICLE
- Concentration in vehicle: no data
- Amount of vehicle (if gavage): 10%
- Justification for choice of vehicle: no data
- Lot/batch no. (if required): no data
- Purity: no data


MAXIMUM DOSE VOLUME APPLIED: 700 mg/kg = 14.0 mL/kg


DOSAGE PREPARATION (if unusual): no data


CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: no data

Doses:

400, 480, 580 and 700 mg/kg

No. of animals per sex per dose:

5 animals/sex/dose

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observation for behaviour and mortality was performed 1, 2, 6 hours post treatment and daily for 14 days, weighing was performed on day 0, 1, 2, 4, 7 and 14 post treatment.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Statistics:

Probit method, Litchfield and Wilcoxon method and Arcsinus method were used.

Results and discussion

Preliminary study:

In a preliminary study, 2-methyl-3-butenenitrile was admistered by oral way to 5 groups of 4 Sprague-Dawley rats (2 males and 2 females) at doses of 100, 500, 1000, 2500 and 5000 mg/kg, after a diet period of 18 days. (See table 7.2.1/1)
At doses of 100 and 500 mg/kg, the test subtance was preliminary diluted in an aqueous dispersion of arabic gumm 10%.
Animals were observed and mortality noted at 1, 2 and 6 hours post-exposure and for 14 days (See table 7.2.1/3).
0% mortality was observed at dose level of 100 mg/kg, 50% mortality at 500mg/kg and 100% mortality at 1000, 2500 and 5000 mg/kg.

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD50

Effect level:

459 mg/kg bw

95% CL:

>= 380 - <= 555

Effect levels 2

Sex:

male

Dose descriptor:

LD50

Effect level:

232 mg/kg bw

Effect levels 3

Sex:

female

Dose descriptor:

LD50

Effect level:

622 mg/kg bw

Mortality:

See table 7.2.1/3
At 400 mg/kg, there was 40% of mortality for males and females.
At 480 mg/kg, there was 50% of mortality for males and females.
At 580 mg/kg, there was 70% of mortality for males and females.
At 700 mg/kg, there was 90% of mortality for males and females.

Clinical signs:

other: At 400 mg/kg and 480 mg/kg: Reduced on spontaneous activity, apathy and ptosis were observed at 1 and 2 hours post-exposure. At 6 hours/day 1 post-exposure, Tremor appeared. At day 2, All these effects disappear. At 580 mg/kg: the same signs as at lower d

Gross pathology:

In animals dead during experiment, haemorrhagic lungs, haemorrhagic digestive tract, haemorrhage and thickening of the peritoneum were observed at autopsy.
When survivors were sacrified, no abnormality were detected at 400 and 700 mg/kg, at 480 mg/kg pale kidneys were observed in one female and at 580 mg/kg thymic involution was observed in one female.

Other findings:

No additional data

Any other information on results incl. tables

Table 7.2.1/3: Preliminary study results of acute toxicity on rats

Administration			Animals		Cumulated mortality
Dose mg/kg	Volume Ml/kg	Concentration %	Weight (g)	Number	1 hr	2 hrs	6 hrs	1 d	2 d	4 d	7 d	14 d	%
100	2.00	5	M 165 F 165	2 2	0 0	0 0	0 0	0 0	0 0	0 0	0 0	0 0	0
500	10.00		M 168 F 165	2 2	0 0	0 0	0 0	2 0	2 0	2 0	2 0	2 0	50
1000	1.23	Undiluted	M 160 F 155	2 2	0 0	0 0	1 0	2 2	2 2	2 2	2 2	2 2	100
2500	3.10		M 154 F 155	2 2	0 0	0 0	0 0	2 2	2 2	2 2	2 2	2 2	100
5000	6.20		M 158 F 154	2 2	0 1	2 2	2 2	2 2	2 2	2 2	2 2	2 2	100

Table 7.2.1/4: Acute toxicity on rats

Administration			Animals		Cumulated mortality
Dose mg/kg	Volume Ml/kg	Concentration %	Weight (g)	Number	1 hr	2 hrs	6 hrs	1 d	2 d	4 d	7 d	14 d	%
Control	14.0	SG 10%	M 162 F 162	5 5	0 0	0 0	0 0	0 0	0 0	0 0	0 0	0 0	0
400	8.0	5	M 164 F 163	5 5	0 0	0 0	1 0	4 0	4 0	4 0	4 0	4 0	40
480	9.6		M 163 F 161	5 5	0 0	0 0	3 0	5 0	5 0	5 0	5 0	5 0	50
580	11.6		M 161 F 160	5 5	0 0	0 0	1 0	5 2	5 2	5 2	5 2	5 2	70
700	14.0		M 161 F 161	5 5	0 0	0 0	1 0	5 2	5 4	5 4	5 4	5 4	90

Table 7.2.1/5: Body weight evolution after exposure of female Sprague-Dawley rats to 2 -methyl-3 -butenenitrile

Dose mg/kg	Mean body weight
	0	1	2	4	7	14
Control	162	176	182	194	201	220
400	163	148*	162*	184*	196	220
480	161	143*	160*	178*	191*	207*
580	160	138	150	162	185	205
700	161	140	155	164	180	206

*Significant at threshold 95%

Applicant's summary and conclusion

Interpretation of results:

Toxicity Category III

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the test conditions of this study, males were more sensitive than females. Therefore, based on the oral LD50 of male rats (= 232 mg/kg bw)
considering as the worst case, 2 -methyl-3 -butenenitrile was classified in Category III (H301: Toxic if swallowed) according to the Regulation 1272/2008/EC and as harmful if swallowed (Xn, R22) according to the Directive 67/548/EEC.

Executive summary:

In an acute toxicity study, 2-methyl-3-butenenitrile was administered by oral route to 5 groups of 10 Sprague-Dawley rats (5 males and 5 females) at dose levels of 0, 400, 480, 580 and 700 mg/kg, after a diet period of 17 days. This study was equivalent or similar to OECD 401 guideline. The test subtance was diluted in an aqueous dispersion of arabic gumm 10%. Animals were observed and mortality noted at 1, 2 and 6 hours post-exposure and for 14 days, and they were weighed on day 0, 1, 2, 4, 7 and 14.

At 400, 480, 580 and 700 mg/kg, there was respectively 40, 50, 70 and 90% of mortality. No death was observed in the control group with vehicle alone administered.

For all dose levels, reduced on spontaneous activity, apathy and ptosis were observed at 1 and 2 hours post-exposure. At 6 hours/day 1 post-exposure, tremor appeared. At day 2 and 3, All these effects disapear.

For females, the body weight decreased significantly at 400 mg/kg from day 1 to day 4 and at 480 mg/kg from day 1 to day 14 (sacrified). In animals dead during experiment, haemorrhagic lungs, haemorrhagic digestive tract, haemorrhage and thickening of the peritoneum were observed at autopsy. When survivors were sacrified, no abnormality was detected at 400 and 700 mg/kg, at 480 mg/kg pale kidneys were observed in one female and at 580 mg/kg thymic involution was observed in one female.

Based on Litchfield and Wilcoxon:

LD50 (males and females) was 459 mg/kg bw (380 -555 mg/kg)

LD50 (males) was 232 mg/kg bw

LD50 (females) was 622 mg/kg bw

Under the test conditions of this study, the male was more sensitive than the female rat. Therefore, based on the oral LD50 of male rats considering as the worst case, 2 -methyl-3 -butenenitrile was considered in Category III (H301: Toxic if swallowed) according to the Regulation 1272/2008/EC and as harmful if swallowed (Xn, R22) according to the Directive 67/548/EEC.