Benzonitrile, 2,3-dichloro-

Endpoint summary

Description of key information

In order to evalute the acute oral toxic potential of 2,3 -Dichlorobenzonitrile a study according to OECD 425 and OPPTS 871 .1100 was performed.

Under the conditions of the present study the estimated LD50 of the test item 2,3-Dichlorobenzonitrile in rats is 550 mg/kg bw.

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:

14.01.- 14.06.2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

GLP compliance:

yes (incl. QA statement)

Test type:

up-and-down procedure

Limit test:

no

Specific details on test material used for the study:

Batch-No.: 529301

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, 97633 Sulzfeld, Germany
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 8 - 12 weeks
- Weight at study initiation:150 - 184 g
- Fasting period before study: 16 - 19 hours
- Housing: The animals were kept in groups in IVC cages, type III H, polysulphona cages on Altromin saw fibre beeding.
- Diet: Free access to Altromin 1324 maintenance diet for rats and mice (lot. no. 2922)
- Water: Free access to tap water, sulphur acified to a pH value of approximately 2.8 (drinking water, municipal residue control, microbiological controls at regular intervals)
- Acclimation period: At least five days under laboratory conditions.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3 °C
- Humidity (%): 55 +/- 10 %
- Air changes (per hr): 10 x/ hour
- Photoperiod: Artificial light, sequence being 12 hours light, 12 hours dark.

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

VEHICLE
- Amount of vehicle (if gavage): 10 mL/kg body weight
- Justification for choice of vehicle: While aqua ad injectionem (sterile water) was not adequate, preparation with corn oil yielded a suspension which was technically applicable to the animals.
- Lot/batch no.: 529301
- Purity: 99.7 %

MAXIMUM DOSE VOLUME APPLIED:
10 mL/kg body weight

Doses:

2000, 550 and 175 mg/kg body weight

No. of animals per sex per dose:

2000 mg/kg bw: 4 females
550 mg/kg bw: 4 females
175 mg/kg bw: 2 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: A careful examination was made several times on the day of dosing (at least once during the first 30 minutes and with special attention given during the first 4 hours post-dose). As soon as symptomy were noticed they were recorded. Thereafter, the animals were observed for clinical signs once daily until the end of the observation period. All abnormalities were recorded. Cageside observations included changes in the skin and fur, eyes and mucous membranes. Also respiratory, circulatory, automic and central nervous systems and somatomotor activitiy and behaviour pattern were examined. Particular attention was directed to observations of tremor, convulsions,salivation, diarrhoea, lethargy, sleep and coma.
- Frequency of weighing: The animals were weighed on day 1 (prior to the administration) and on days 8 and 15.
- Necropsy of survivors performed: yes

Key result

Sex:

female

Dose descriptor:

LD50 cut-off

Effect level:

550 mg/kg bw

Based on:

test mat.

Mortality:

All animals treated with the test item at a dose of 2000 mg/kg bw and one animal treated with the test item at a dose of 550 mg/kg had to be sacrified for ethical reasons on test day1. All remaining animals survived until the end of the study.

Clinical signs:

other: The most relevant clinical findings in the animals treated with the test item at a dose of 2000 mg/kg bw were reduced spontaneous activity, apathy, prone position, ataxia, slow movements, wasp waist, eyes half closed, eyes closed, abnormal breathing, hypo

Gross pathology:

With the expection of acute injection of blood vessels in the abdominal region, which is due to the euthanasia injection, no specific gross pathological changes were recordedfor any other animal. At necropsy, in the stomach of animal 1 (2000 mg/kg bw) residual test item was found.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Under the conditions of the present study and according to OECD Guideline 425 and OPPTS 871.1100 the estimated LD50 of the test item 2,3-Dichlorobenzonitrile in rats is 550 mg/kg bw (based on an assumed sigma of 0.5).

Executive summary:

In order to evalute the acute toxic potential of 2,3 -Dichlorobenzonitrile a study according to OECD 425 and OPPTS 871 .1100 was performed.

All animals treated with the test item at a dose of 2000 mg/kg bw and one animal treated with the test item at a dose of 550 mg/kg had to be sacrified for ethical reasons on test day1. All remaining animals survived until the end of the study.

The most relevant clinical findings in the animals treated with the test item at a dose of 2000 mg/kg bw were reduced spontaneous activity, apathy, prone position, ataxia, slow movements, wasp waist, eyes half closed, eyes closed, abnormal breathing, hypothermia, lacrimation and comatose. The most relevant clinical findings in the animals treated with the test item at a dose of 550 mg/kg bw were reduced spontaneous activity, prone position, hunched posture, ataxia, slow movements, moving the bedding, wasp waist, eyes half closed, piloerection, abnormal breathing, lacrimation and salivation. The most relevant clinical findings in the animals treated with the test item at a dose of 175 mg/kg bw were reduced spontaneous activity, hunched posture, slow movements, wasp waist, piloerection, eyes half closed and eyes closed.

All surviving animals gained weight during the observation period. Througout the 14-day observation period, the weight gain of surviving animals was within the normal range of variation for this strain.

With the expection of acute injection of blood vessels in the abdominal region, which is due to the euthanasia injection, no specific gross pathological changes were recorded for any other animal. At necropsy, in the stomach of animal 1 (2000 mg/kg bw) residual test item was found.

Under the conditions of the present study and according to OECD Guideline 425 and OPPTS 871.1100 the estimated LD50 of the test item 2,3-Dichlorobenzonitrile in rats is 550 mg/kg bw (based on an assumed sigma of 0.5).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

550 mg/kg bw

Justification for classification or non-classification

Under the conditions of the present study and according to OECD Guideline 425 and OPPTS 871.1100 the estimated oral LD50 of the test item 2,3-Dichlorobenzonitrile in rats is 550 mg/kg bw.

On the basis of the test results and the criteria given in GHS (Globally Harmonized System of Classification and Labelling of Chemicals) the substance 2,3 -Dichlorobenzonitrile should be classified into category 4 and labelled with H302: Harmful if swallowed.