diuron (ISO); 3-(3,4-dichlorophenyl)-1,1-dimethylurea

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1983

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1983

Report date:

1983

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

1984

GLP compliance:

not specified

Test type:

acute toxic class method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Diuron

EC Number:

206-354-4

EC Name:

Diuron

Cas Number:

330-54-1

Molecular formula:

C9H10Cl2N2O

IUPAC Name:

3-(3,4-dichlorophenyl)-1,1-dimethylurea

Details on test material:

- Substance type: organic
- Physical state: white to yellowish solid
- Analytical purity: 98.8%
- Lot/batch No.: 232114080

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Winkelmann, Borchen, Germany
- Weight at study initiation: 160 - 200 g
- Fasting period before study: over night
- Housing: conventional Makrolon cages, 5 animals per cage
- Diet: "Altromin Diet for rats and mice"
- Acclimation period: at least three days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 25
- Humidity (%): 40 - 60
- Photoperiod (hrs dark / hrs light): 12 h dark/ 12 h light

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: distilled water with Cremophor EL

Details on oral exposure:

VEHICLE
- Concentration in vehicle: Cremophor EL (5 drops/10 mL distilled water)

Doses:

25, 50, 1000, 2500, 5000 and 7100 mg/kg bw
total volume applied: 1 mL/100 g b.w.

No. of animals per sex per dose:

10 per group

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs

Method of determination of LD50: Litchfield & Wilcoxon (1949)

Results and discussion

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

4 150 mg/kg bw

Based on:

test mat.

Mortality:

Mortalities occurred at 2500 mg/kg and above within 2 days.

Clinical signs:

other: At the lowest dose level, no clinical signs were noted. Higher dose levels revealed behavioural, respiratory and motility disorders. Some animals exhibited a narcosis-like state and lying on side or stomach. Signs were noted between 27 min (high dose l

Gross pathology:

Sacrificed animals at study termination showed a dark and slightly enlarged spleen.
In animals that died during the entire study, gross pathological findings were:
patchy, distended lungs, patchy spleen, liver and kidneys, reddened glandular stomach, dark spleen

Applicant's summary and conclusion

Executive summary:

In a reliable acute toxicity study comparable to guideline OECD 401 female rats were dosed with 25, 50, 100, 2500, 5000 and 7100 mg/kg bw Diuron (Heimann and Thyssen, 1983). At the lowest dose level, no clinical signs were noted. Higher dose levels revealed behavioural, respiratory and motility disorders. Some animals exhibited a narcosis-like state and lying on side or stomach. Signs were noted between 27 min (high dose levels) and 2 hours at lower doses following administration. Mortalities occurred at 2500 mg/kg and above within 2 days. Therefore, the LD50 was calculated to be 4150 mg/kg bw.