1,3-dimethyl-1,3-diphenylurea

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21.11.-7.12.2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was carried out in accordance with internationally valid GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1,3-diethyldiphenylurea

EC Number:

201-645-2

EC Name:

1,3-diethyldiphenylurea

Cas Number:

85-98-3

Molecular formula:

C17H20N2O

IUPAC Name:

1,3-diethyl-1,3-diphenylurea

Test material form:

other: crystalline

Details on test material:

- Name of test material (as cited in study report): Centralit- Substance type: pure substance- Physical state: white crystalline powder- Analytical purity: 99.9% (w/w)- Expiration date of the lot/batch: 16.9.2016- Stability under test conditions: stable- Storage condition of test material: in dry room at the laboratory temperature- pH: approximately 7

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Breeding farm VELAZ s.r.o., Koleč u Kladna, Czech Republic
- Weight at study initiation: average-females: 213.9 g, average-males: 252.34 g
- Housing: animal room with monitored conditions – one animal in one plastic cage
- Diet (e.g. ad libitum): ST 1 BERGMAN – standard pelleted diet
- Water (e.g. ad libitum): drinking tap water
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22+/-3°C
- Humidity (%): 30-70%
- Air changes (per hr): approximately 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 hour light/12 hour dark

STUDY TIME SCHEDULE
Animal supply: 16. 11. 2011
Experimental part of study: 21. 11. – 07. 12. 2011

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: 6x6 cm
- % coverage: aprox. 10% of the body surface
- Type of wrap if used: The application site was covered by mull and held in contact by plaster (strapping).

REMOVAL OF TEST SUBSTANCE
- Washing (if done): water
- Time after start of exposure: 24 hrs

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): according to its body weight and the dose (2000 mg/kg)
- For solids, paste formed: no

Duration of exposure:

24 hrs

Doses:

2000 mg/kg bw.

No. of animals per sex per dose:

5 females and 5 males

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
- body weight: before application, 8th day of clinical observation and at the end of study (15th day)
- mortality: daily
- clinical signs: daily
- Necropsy of survivors performed: yes

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

The test substance did not cause death of animals.

Clinical signs:

No clinical signs of intoxication were observed.

Body weight:

In males and females, the weight increments were adequate to species and age of animals in the experiment.

Gross pathology:

No macroscopic changes were diagnosed during pathological examination in all animals.

Applicant's summary and conclusion

Interpretation of results:

practically nontoxic

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

According to the results of the dermal toxicity study, the value of LD50 (dermal) of test substance, Centralit, for rats is higher than 2000 mg/kg of body weight.

Executive summary:

The test substance, Centralit, was tested for acute dermal toxicity using Wistar rats.

Testing was performed according to the Method B.3 Acute Toxicity (Dermal), Council Regulation (EC) No.440/2008, published in O.J. L 142, 2008.

The study was performed as limit test: two groups of animals – 5 males and 5 females at the dose of 2000 mg/kg of body weight. The pre-test was performed with 1 male and 1 female from each group. After end exposure test substance of these pilot animals, the other animals of the group were dosed.

The test substance was applied on the shaved skin of the test animals in delivered form for 24 hours.

The test animals were observed 14 days after exposure test substance, afterwards they were sacrificed, and the necropsy for macroscopic examination of the organs was performed.

The test substance applied at the dose of 2000 mg/kg of body weight did not cause death of animals. No clinical signs of intoxication were observed. No macroscopic change was diagnosed during pathological examination of animals.

According to the results of study, the value of LD50 (dermal) of the test substance, Centralit, for rats of both sexes is higher than 2000 mg/kg of body weight.