Dichlobenil

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

8 December 1993 to 19 May 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPP 81-2 (Acute Dermal Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Dichlobenil

EC Number:

214-787-5

EC Name:

Dichlobenil

Cas Number:

1194-65-6

Molecular formula:

C7H3Cl2N

IUPAC Name:

2,6-dichlorobenzonitrile

Test material form:

solid: particulate/powder

Details on test material:

- Physical state: solid
- Storage condition of test material: in the dark at ambient room temperature

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: four months old
- Weight at study initiation: 2.68-2.90 kg (male); 2.84-3.09 (female)
- Housing: individually in suspended stainless steel cages
- Diet: ad libitum
- Water: tap water ad libitum
- Acclimation period: at least five days

ENVIRONMENTAL CONDITIONS
- Temperature: 15-23 ºC
- Humidity: 40-70 %
- Air changes: at least 10
- Photoperiod: 12 hours light/12 hours dark

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: 12 cm x 14 cm
- % coverage: approximately 10 %
- Type of wrap if used: unmedicated gauze patch; occluded with aluminium foil

REMOVAL OF TEST SUBSTANCE
- Washing (if done): gently wiped with wet tissues

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

Five

Control animals:

no

Details on study design:

- Duration of observation period following administration: 15 days
- Frequency of observations and weighing: three separate observations were made during the first hour after administration and two further recordings were made during day 1. From day 2 onwards, the animals were inspected at least twice daily and recordings of systemic signs made once daily.
- Necropsy of survivors performed: yes
- Other examinations performed: body weights were recorded on the day before dosing and days 1, 8 and 15.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

Two female rabbits were found dead on day 5

Clinical signs:

other: Ante mortem signs comprised under-activity, pallor, cold to touch, pigmented straining of the snout and closed eyes. One surviving female rabbit showed pallor on day 4. The other surviving animals showed no systemic or local sign of reaction to treatment.

Gross pathology:

Necropsy of the deceased animals revealed blood staining around the mouth and nares of both animals, dark tracheal contents and dark areas on the left lung lobe of one animal and dark fluid in the thorax and abdomen of the other animal. The latter animal also had a thickened dermal application site with dark encrustations.

Necropsy of the surviving animals revealed no significant internal macroscopic lesion, although one animal had multiple dark areas in the musculature below the application site.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of the test, the LD50 of the test material was >2000 mg/kg.

Executive summary:

In a GLP compliant acute dermal toxicity study conducted in line with standardised guidelines OECD 402, EU Method B.3 and EPA FIFRA Guideline 81-2, the acute dermal toxicity of the test material was determined.

Under the conditions of the test, the LD₅₀ of the test material was determined to be >2000 mg/kg bw and so the substance is considered to be unclassified for this endpoint.