(4E)-4-methyl-5-(4-methylphenyl)pent-4-enal

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12-26 March 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP study conducted in compliance with OECD Guideline No. 402 without any deviation.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

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))

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

UK GLP Compliance Programme (inspected on July 10, 2012/ signed on November 30, 2012)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(4E)-4-methyl-5-(4-methylphenyl)pent-4-enal

Cas Number:

1226911-69-8

Molecular formula:

C13H16O

IUPAC Name:

(4E)-4-methyl-5-(4-methylphenyl)pent-4-enal

Test material form:

liquid

Details on test material:

- Physical state: Pale yellow liquid
- Storage condition of test material: Approximately 4 °C in the dark under nitrogen

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories UK Limited, Bicester, Oxon, UK.
- Females nulliparous and non-pregnant: Yes
- Age at study initiation: 8-12 weeks
- Weight at study initiation: 241-252 g (males); 207-216 g (females)
- Housing: Animals were housed in suspended solid-floor polypropylene cages furnished with woodflakes. Animals were housed individually during the 24 hour exposure period and in groups of five by sex for the remainder of the study
- Diet: Food (2014 Teklad Global Rodent diet supplied by Harlan Laboratories UK Ltd., Oxon, UK), ad libitum
- Water: Mains drinking water, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 19-25 °C
- Humidity: 30-70 %
- Air changes: 15 changes/h
- Photoperiod: 12 h dark / 12 h light

IN-LIFE DATES: 12-26 March 2014

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Pretreatment: On the day before treatment the back and flanks of each animal were clipped free of hair.
- Area of exposure: Back and flank area
- % coverage: Approximately 10 % of the total body surface area.
- Application of test item: Test item was used as supplied. The test item was applied as evenly as possible to an area of shorn skin (approximately 10 % of the total body surface area) using a graduated syringe.
- Type of wrap if used: A piece of surgical gauze was placed over the treatment area and semi-occluded with a piece of self-adhesive bandage. The animals were caged individually for the 24 hour exposure period. Shortly after dosing the dressings were examined to ensure that they were securely in place.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): After the 24 hour contact period the bandage was carefully removed and the treated skin and surrounding hair wiped with cotton wool moistened with distilled water to remove any residual test item. The animals were returned to group housing for the remainder of the study period.
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg bw
- Specific gravity of test item: 0.991
- Constant volume or concentration used: Yes; 2.02 mL/kg bw

Duration of exposure:

24 h

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: Animals were observed for mortality or clinical signs of toxicity at 0.5, 1, 2 and 4 h after dosing and subsequently once daily for 14 days. After removal of the dressings and subsequently once daily for 14 days, the test sites were examined for evidence of primary irritation and scored according to Draize scale.
- Frequency of weighing: Individual body weights were recorded prior to application of the test item on Day 0 and on Days 7 and 14.
- Necropsy of survivors performed: Yes; at the end of the study animals were killed by cervical dislocation and subjected to gross necropsy.

Statistics:

None

Results and discussion

Preliminary study:

Not applicable

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: no mortality was observed

Mortality:

No mortality was observed.

Clinical signs:

No signs of systemic toxicity were noted during the observation period.

Body weight:

- Three females showed body weight loss or no gain in body weight during the first week with expected gain in body weight during the second week.
- The remaining animals showed expected gains in body weight over the study period.

Gross pathology:

No abnormalities were noted at necropsy.

Other findings:

There were no signs of dermal irritation.

Any other information on results incl. tables

None

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Dermal LD50 Combined > 2000 mg/kg bw. Under the experimental conditions of this study, the test item is not classified according to Regulation (EC) No. 1272/2008 (CLP) and to GHS.

Executive summary:

In an acute dermal toxicity study (limit test) performed according to OECD Guideline No. 402 and in compliance with GLP, a group of Wistar (RccHan™:WIST) rats (5/sex) was given a single dermal application of the undiluted test item at 2000 mg/kg bw to intact skin of the back and flank area at the dose volume of 2.02 mL/kg bw. Test sites were covered with a semi-occlusive dressing for 24 h. Animals were observed for mortality, clinical signs and bodyweights for 14 days and at the end of the study the surviving animals were sacrificed for macroscopic examination. Skin irritation was assessed and scored according to the Draize scale at 24 h after removal of the dressings and then daily for 14 days.

 

No mortality, signs of dermal irritation or systemic toxicity were observed. Three females showed body weight loss or no gain in body weight during the first week with expected gain in body weight during the second week. The remaining animals showed expected gains in body weight over the study period. No abnormalities were noted at necropsy.

 

Dermal LD50 Combined > 2000 mg/kg bw

 

Under the experimental conditions of this study, the test item is not classified according to Regulation (EC) No. 1272/2008 (CLP) and to GHS.

This study is considered as acceptable and satisfies the requirement for acute dermal toxicity endpoint.