(E)-2-methoxy-4-(prop-1-enyl)phenol

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From November 21, 1978 to April 23, 1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

This study was performed prior to the OECD test guideline No. 402 but the protocol is similar to that guidance.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

(occlusive dressing, 3 animals/sex used; no details on environmental condition of animal room)

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

(E)-2-methoxy-4-(prop-1-enyl)phenol

EC Number:

227-678-2

EC Name:

(E)-2-methoxy-4-(prop-1-enyl)phenol

Cas Number:

5932-68-3

Molecular formula:

C10H12O2

IUPAC Name:

2-methoxy-4-prop-1-en-1-ylphenol

Test material form:

liquid

Details on test material:

- Physical state: Clear liquid

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: C.S.E. colony, Branchville, N.J.
- Weight at study initiation: 2-3.4 kg
- Housing: Animals were housed individually under standard laboratory conditions.
- Diet: Purina Rabbit Chow, ad libitum
- Water: Water, ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS: Animals were housed and maintained according to 'Guide for the Care and use of Laboratory Animals'. DHEW Publication No. (NIH) 78-23. Revised 1978.

IN-LIFE DATES: From: November 11 1978 To: March 1979

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: Dorsal surface of the trunk
- % coverage: 20 % of the entire body surface
- Type of wrap if used: Opened plastic sleeves (Baggies) were placed over the trunk and the posterior end was taped against the animal. Test material was applied over the prepared skin and the anterior end of the sleeve was taped against the animal, allowing the central portion to balloon. Elastic tape (Elastikon) was then lightly wrapped around the sleeve to reduce the chance of puncture or dislocation of the sleeve.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Excess material was cleansed from the skin using a clean disposable napkin moistened with saline.
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.8, 1.25, 1.57, 1.98, 3.15 and 5 mL/kg bw

Duration of exposure:

24 h

Doses:

0.8, 1.25, 1.57, 1.98, 3.15 and 5 mL/kg bw

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed for signs of toxicity or mortality twice daily (once daily on Saturday and Sunday) for 14 days.
- Necropsy of survivors performed: yes; any dead animals and all survivors were subjected to gross necropsy.

Statistics:

The LD50, slope and fiducial limits of the combined male and female mortality were estimated by the graphic method of Litchfield and Wilcoxon (1949)

Results and discussion

Preliminary study:

Not applicable

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1.77 mL/kg bw

Based on:

test mat.

95% CL:

> 1.35 - < 2.32

Remarks on result:

other: Equivalent to 1911.6 mg/kg bw (fiducial limits 1458-2506 mg/kg bw)

Mortality:

- No mortality was observed at 0.8 mL/kg bw.
- 1/6, 2/6, 4/6, 6/6 and 6/6 animals died at 1.25, 1.57, 1.98, 3.15 and 5 mL/kg bw, respectively. The majority of the deaths occurred within 24 hours.

Clinical signs:

other: - Systemic toxicity occurred in animals at all doses except 0.8 mL/kg bw. - At 1.25 mL/kg bw, skin became erythematous and haemorrhagic areas were developed. Following drying and thickening, the skin was healed by termination. - At 1.57 mL/kg bw, intrade

Gross pathology:

- At 5 mL/kg bw effects observed at necropsy were congestion of the lungs.
- At 3.15 mL/kg bw, the major effects observed at necropsy were congestion of the lungs and failure of the vascular system characterized by haemorrhage, either locally into treated skin or into visceral organs
- At 1.98 mL/kg bw the major effects observed at necropsy were eschar formation and bruising of the skin and congestion of the lungs.
- At 1.57 and 1.25 mL/kg bw, 2/6 and 1/6 rabbits had congested lungs, respectively.
- At 0.8 mL/kg bw, no meaningful lesions were detected at necropsy.

Other findings:

None

Any other information on results incl. tables

None

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

Under the test conditions, test material is classified Category 4 (H312: Harmful iin contact with skin) according to the Regulation (EC) No. 1272/2008 and to the GHS as the LD50 value is comprised between 300 and 2000 mg/kg bw.

Executive summary:

In an acute dermal toxicity study, groups of New Zealand White rabbits (3/sex/dose) were given a single dermal application of undiluted test material at 0.8, 1.25,1.57, 1.98, 3.15 and 5.0 mL/kg bw to intact skin on the back. Test sites were covered with an occlusive dressing for 24 h. Animals were observed for mortality, clinical signs and bodyweights for 14 days. Animals which died and all survivors were subjected to gross necropsy.

No mortality was observed at 0.8 mL/kg bw. 1/6, 2/6, 4/6, 6/6 and 6/6 animals died at 1.25, 1.57, 1.98, 3.15 and 5 mL/kg bw, respectively. Thickening of the skin and varying degrees of erythema were observed. Eschar formation developed and necrotic patches began to exfoliate at about Day 7, continuing until termination, and leaving a healthy healing skin under the slough. Systemic toxicity occurred in animals at all doses except 0.8 mL/kg bw. Animals had dyspnea (either slow and laboured or very rapid breathing), nasal discharge (ranging from blood-tinged and frothy to thick and opaque) and congested lungs were found upon necropsy. The incidence and severity of the signs were least in the lower dose groups. All surviving animals showed normal bodyweight gain over the 14-day study period, except for three males (one each from 0.8, 1.25 and 1.98 mL/kg bw group) and one female treated with 0.8 mL/kg bw which showed body weight loss.

Dermal LD50 Combined = 1.77 mL/kg bw (fiducial limits1.35-2.32 mL/kg bw) [equivalent to 1911.6 mg/kg bw (fiducial limits 1458-2505.6 mg/kg bw).

Under the test conditions, test material is classified Category 4 (H312: Harmful iin contact with skin) according to the Regulation (EC) No. 1272/2008 and to the GHS as the LD50 value is comprised between 300 and 2000 mg/kg bw.

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