1,1-dimethoxy-2-phenylethane

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 Oct - 06 Nov 2015

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

occlusive conditions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

1987

Deviations:

yes

Remarks:

occlusive instead of semi-occlusive conditions

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1,1-dimethoxy-2-phenylethane

EC Number:

202-945-6

EC Name:

1,1-dimethoxy-2-phenylethane

Cas Number:

101-48-4

Molecular formula:

C10H14O2

IUPAC Name:

(2,2-dimethoxyethyl)benzene

Test animals

Species:

rat

Strain:

other: Crl:CD(SD), SPF

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 8 weeks (males), 9 weeks (females)
- Weight at study initiation: 270.3 - 285.4 g (males), 215.4 - 248.0 (females)
- Housing: individually in stainless wire mech cages (260W x 350D x 210H mm)
- Diet: Teklad Certified Irradiated Global 18% Protein Rodent Diet 2918C (Harlan Laboratories, Inc., USA), ad libitum
- Water: public tap water filtered and irradiated by ultraviolet light, ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.9 - 22.6
- Humidity (%): 46.9 - 56.0
- Air changes (per hr): 10 - 15
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

A preliminary study was conducted to select the dose level for the main study.

TEST SITE
- Area of exposure: skin of the subscapular dorsal surface (approx. 5 cm x 6 cm)
- Type of wrap if used: After the application of the test substance to a lint tape, the application site was covered with the lint tape and plastic film. The back of the animals was over-wrapped with Soft Cloth Tape with Liner (5 cm width) and surgical tape.The application site of control animals was covered with the lint tape, plastic film and Soft Cloth Tape with Liner and surgical tape in the same manner as dosed animals.

REMOVAL OF TEST SUBSTANCE
- Washing: Any residual test substance was removed using absorbent cotton moistened with tepid water.
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount applied: 4.98 mL/kg bw
- Constant concentration used: yes

Duration of exposure:

24 h

Doses:

Preliminary study: 5000 mg/kg bw
Main study: 0 and 5000 mg/kg bw

No. of animals per sex per dose:

Preliminary study: 1 male and 1 female
Main study: 5 males and 5 females

Control animals:

yes, concurrent no treatment

Details on study design:

Preliminary study:
- Duration of observation period following administration: 3 days
- Frequency of observations: Individual body weights were recorded on the day of treatment and on Day 3.
- Necropsy of survivors performed: no

Main study:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed 30 min and 1, 2, 4 and 6 h after dosing and thereafter once daily for 14 days. Individual body weights were recorded prior to dosing on Day 0 and on Days 3, 7 and on the day of necropsy, Day 14.
- Necropsy of survivors performed: yes

Statistics:

Statistical analysis was performed using SAS Program (version 9.3). Body weights were analyzed utilizing Folded-F test for homogeneity of variance (significance level: 0.05). Student t-test was employed on homogeneous data (significance level: 0.05) or Aspin-Welch t-test was employed on heterogeneous data (significance level: 0.05) for confirming significance (significance levels: 0.05 and 0.01, two-tailed), respectively.

Results and discussion

Preliminary study:

No deaths or clinical signs of toxicity were noted at 5000 mg/kg bw throughout the 3-day observation period. The dose level selected for the main study was therefore 5000 mg/kg bw.

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred during the study period of the main study.

Clinical signs:

other: No signs of systemic toxicity were noted during the main study.

Gross pathology:

No abnormalities were noted at necropsy.

Applicant's summary and conclusion

Interpretation of results:

other: CLP/EU GHS criteria not met, no classification required according to Regulation (EC) No 1272/2008

Conclusions:

In this acute dermal toxicity study a LD50 value > 5000 mg/kg bw in male and female rats was found.

Executive summary:

The acute dermal toxicity of the test substance was assessed in a study according to OECD Guideline 402 and in compliance with GLP (2015b). In a preliminary study, 1 male and female rat, respectively, were treated dermally with 5000 mg/kg bw test substance. Since no mortality was observed at 5000 mg/kg bw this dose level was selected for the main study. In the main study, 5 male and female rats, respectively, were treated dermally with test substance under occlusive conditions for 24 hours. Additionally, a control group consisting of 5 male and female rats, respectively, was treated in the same manner as dosed animals except that the test substance was omitted. Animals were subjected for mortality, general condition and clinical signs at 0.5, 1, 2, 4 and 6 hours after dosing on Day 0 and subsequently once daily for 14 days. Individual body weights were recorded prior to application of the test substance on Day 0 and on Days 3, 7 and 14 days after treatment. Macroscopic examination was performed in the end of the observation period at terminal sacrifice. There was no mortality and no effects on body weight gain during the 14-day observation period. No clinical abnormalities were evident in any animal throughout the study. Macroscopic postmortem examination did not reveal any abnormalities. The LD50 value for dermal toxicity was considered to be > 5000 mg/kg bw.