Bis(2-ethylhexyl) 2-(4-hydroxy-3,5-dimethoxybenzylidene)malonate

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2004-09-03 to 2004-12-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

adopted 24 February 1987

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

29 December 1992

Deviations:

no

Principles of method if other than guideline:

None

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Test material

Reference

Name:

Unnamed

Type:

Constituent

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Test system
Species: Rat, Wistar HsdCpb: WU, males (m) and females (f)
Age: approx. 9 to 13 weeks

- Identification and adaptation
Healthy young animals were allocated to the study group at least 7 days before dosing to allow for acclimatization.
The rats were identified by an ear punching and additionally with an ear tattoo.

- Housing and diet
The rats were housed in an air-conditioned room of about 25 m^2. Lighting was controlled by a timer to provide a 12 hour light - 12 hour dark regime.

The rats were kept separately in type III Makrolon cages with a shelter, placed on mobile racks. Conventional softwood granulate was used
as the bedding. One day before treatment, and up to 24 hours after dosing, metal grids were placed above the softwood granulate.
The cages and the metal grids had been machine-cleaned before the start of the experimental part. The bedding was changed two times per
week.

Temperature and humidity were measured using a thermohygrograph. The room temperature during the experimental period was 22 to 24 °C
and the relative atmospheric humidity 42 to 62 %.

Diet, Provimi Kliba 3433.0, and tap water from Makrolon drinking bottles were available to the rats ad libitum.

The die had been checked according to the specifications of the manufacturer by independent laboratories.
Analysis included qualitative and quantitative evaluation for heavy metals, aflatoxins, pesticides, and antibiotics.
The drinking water was periodically analyzed according to the German regulations for human drinking water.

The softwood granulate was analytically checked by independent laboratories.

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

The backs and abdomens of the rats were shaved with an electric hair clipper not later than one hour before treatment.
The test material was prepared, spread on the shaven skin in an area of 6 x 6 cm, and covered with a gauze patch. This was kept in place by a self-adhesive fabric (Fixomull® stretch, Beiersdorf). The time of exposure was 24 hours. Then the gauze and adhesive fabric were removed and any remaining test material was wiped off carefully.

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5 (males) / 5 (females)

Control animals:

no

Details on study design:

-- Observation for clinical symptoms
On the day of treatment the general condition and motility of the rats were slightly affected by the tape. It was difficult to distinguish between slight clinical findings and reactions due to fixation by the tape. The behavior and general condition of all rats were monitored for at least 6 hours after administration and then checked daily.

-- Body weight
All animals were weighed before treatment and on days 2, 4, 6, 8, 11, 13, and 15 of the experimental part.

-- Pathology
All rats were sacrificed at the end of the experimental part by CO2-asphyxia. They were subjected to a gross pathological investigation.

Statistics:

The body weight data were processed using a PC-program. The body weight development of each rat and group was determined. The group mean value was calculated for each measurement and printed on tables.

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:

One animal was accidentally hurt removing the gauze patch and was sacrificed for human reasons on day 1 of the experimental part.
All the other rats survived the observation period.

Clinical signs:

No signs of toxicity were detected in the 5 male and 5 female rats after dermal treatment with 2000 mg/kg of the test item.

Body weight:

The body weight development of the treated rats was inconspicuous.

Gross pathology:

At necropsy, no organ alterations were seen.

Other findings:

None

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the result of this study in rats, the test substance can be considered to have no acute toxic potential after dermal administration and the LD50 value is higher than the limit dose of 2000 mg/kg.

Executive summary:

Purpose

The purpose of this assay was to provide information on possible health hazards of the test item and serve as a rational basis for risk assessment to the potential of acute dermal toxicity of the test item in man.

Study design

The study was performed according to the OECD Guideline for Testing of Chemicals, No. 402 and according to Commission Directive 92/69/EEC B3.

Results

No signs of toxicity were detected in the rats (4 males and 5 females) after treatment with 2000 mg/kg. One animal was accidentally hurt removing the gauze patch and was sacrificed for human reasons on day 1 of the experimental part. All the other rats survived the observation period.

The body weight development was inconspicuous The gross pathological examination revealed no organ alterations.

Conclusions

Based on the result of this study, the test item can be considered to have no acute toxic potential and the expected LD50 value is higher than 2000 mg/kg after dermal administration to rats.