2-hydroxy-4-(methylthio)butyronitrile

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 9 july 1990 To 27 February 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study (OECD TG 401) without data on purity of the substance.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-hydroxy-4-(methylthio)butyronitrile

EC Number:

241-756-3

EC Name:

2-hydroxy-4-(methylthio)butyronitrile

Cas Number:

17773-41-0

Molecular formula:

C5H9NOS

IUPAC Name:

2-hydroxy-4-(methylsulfanyl)butanenitrile

Details on test material:

- Name of test material (as cited in study report): cyanhydrine de l'aldehyde methylthiopropionique (AMTP)
- Physical state: pale yellow clear liquid
- Analytical purity: no data
- Purity test date: no data
- Lot/batch No.: GL-1141-C
- Expiration date of the lot/batch: no data
- Storage condition of test material: at room temperature, away from light

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Iffa-Crédo (69592 L'Arbresle Cedex- France)
- Age at study initiation: between 5 an 7 weeks old
- Weight at study initiation: from 134 to 177 g
- Housing: housed by sex and in group of 5
- Diet : ad libitum, (U.A.R formula A.04 CR - U.A.R, 91360 Epinay-sur-Orge, France)
- Water : ad libitum, water filtered by a FG Millipore membrane (0.22 micron)
- Acclimation period: 10 days before the beginning of the study


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 to 24
- Humidity (%): 28 to 80
- Air changes (per hr): at least 10
- Photoperiod : 12 hrs dark / 12 hrs light


IN-LIFE DATES: From: 1999 To: 1999

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 0.064 ml/kg

Doses:

0, 67, 133, 255, 500 and 1010 mg/kg (preliminary study)
0, 35.5, 44.4, 56.6 and 71 mg/kg (main study)

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: clinical signs were noted 15 minutes after administration of the test article, then at 1, 2 and 4 hours and then daily for the 14 day study period, animals were weighed the day before treatment (Day - 1), immediately before administration of the test article (Day 1), at Days 8 and 15 as well as at the time of death from Day 2 onwards.
- Necropsy of survivors performed: yes

Statistics:

Two methods were used and compared:
- Bliss method (1938): Given that the hypothesis of the effect/logarithm of the dose is linear, this is the most rigorous method.
- Litchfield & Wilcoxon's method (1949): A simplified manual version of the above, with less reliable results. It was used a great deal before the general introduction of computers and is retained to facilitate comparison with other studies.

The two methods use the fact that the straight line of least squares expresses the probit of a lethal fraquency as a function of a Neperian logarithm of the dose. The results obtained from an initial calculation will be then analysed differently for each method. In Bliss (1938), all the data points are used and compared according to their distance from the LD50. In Litchfield & Wilcoxon (1949) only those data points at 0% and 100% of effect are plotted and all the other points are placed equally between.

Results and discussion

Preliminary study:

44 mg/kg: 2 /2 males died and 0/2 females died
67 mg/kg: 2/2 males died and 2/2 females died
133 mg/kg: 1/2 males died and 2/2 females died
255 mg/kg: 2/2 males died and 1/2 females died
500 mg/kg: 2/2 males died and 2/2 females died
1010 mg/kg: 2/2 males died and 2/2 females died

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD50

Effect level:

49 mg/kg bw

95% CL:

41 - 57

Remarks on result:

other: BLISS method

Effect levels 2

Sex:

male/female

Dose descriptor:

LD50

Effect level:

48 mg/kg bw

95% CL:

40 - 58

Remarks on result:

other: Litchfield & Wilcoxon method

Mortality:

Mortality occured during the study with all dose levels tested. For more details see Table 1 in Remark field.

Clinical signs:

other: Lethargy or ataxia were observed in some animals at each dose levels.

Gross pathology:

Dead animals during the study revealed congestif or slightly congestif intestin and lung.
Sacrified animals at the end of the test revealed no anomaly

Other findings:

none

Any other information on results incl. tables

Table 1: Number of animals dead and time range within which mortality occurred

Dose (mg/kg bw)	Mortality (# dead/total)			Time range of deaths (hours)	total mortality %
	Male	Female	Combined
0	0	0	0	-	0
35.5	0	2	2	1 - 2	20
44.4	3	2	5	1 - 4	50
56.6 (lot 1)	2	0	2	1 - 2	20
56.6 (lot 2)	4	1	5	1 - 4	50
71.0	5	4	9	0 - 1	90

Applicant's summary and conclusion

Interpretation of results:

other: category 2

Remarks:

Criteria used for interpretation of results: other: CLP

Conclusions:

Under the conditions of this test, cyanhydrine de l'AMTP induced mortality and is classified as toxic according to Directive 67/548/EEC and category 2 according to CLP (EU-GHS classification).

Executive summary:

In an acute oral toxicity study, groups of fasted Sprague-Dawley rats (5 males and 5 females) were given a single oral dose by gastric gavage of cyanhydrine de l'AMTP at dose levels of 0, 35.5, 44.4, 56.6 and 71 mg/kg bw and observed for 14 days. The dose levels were chosen as a function of the results of a preliminary study and calculated according to a logarithmic progression of 1.26. Mortality occured at each dose level and was treatment related. Lethargy, sleeping or coma were the clinical signs observed in some animals after test substance administration. Congestive lung and intestine were observed in treated related dead animals. No macroscopic abnormalities were observed in surviving animals. From the results obtained under the experimental conditions employed, the LD50 by the oral route, of the test article is equal to 49 mg/kg according to Bliss'method and 48 mg/kg according to Litchfield & Wilcoxon's method.

Under the conditions of this test, cyanhydrine de l'AMTP is therefore classified as toxic according to Directive 67/548/EEC and category 2 according to CLP (GHS classification).

This acute oral study is classified as reliable with restriction considering that the study was performed according to OECD guideline requirements (401) and according to GLP procedure but without data on the purity of the test substance.