Ethoxyquin

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

Peer-reviewed assessment report (attached in section 13)

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EPA OPP 81-2 (Acute Dermal Toxicity)

Version / remarks:

US EPA FIFRA Guideline §81-2

Deviations:

yes

Remarks:

Purity of the test compound was not determined by the laboratory prior to conduct of the test.

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

not applicable

GLP compliance:

yes

Remarks:

self-certified to US EPA regulations at 40 CFR Parts 160 and 792

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Ethoxyquin

EC Number:

202-075-7

EC Name:

Ethoxyquin

Cas Number:

91-53-2

Molecular formula:

C14H19NO

IUPAC Name:

ethoxyquin

Details on test material:

Chemical name
IUPAC: 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline
CAS: 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline

Test animals

Species:

rat

Strain:

other: Crl:CD®BR albino rats

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc. Portage MI USA

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: clipped, intact skin

REMOVAL OF TEST SUBSTANCE yes

Duration of exposure:

24h

Doses:

2000 mg/kg bw / 1.98 mL/kg bw

No. of animals per sex per dose:

5/sex/dose

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, dermal findings

Results and discussion

Effect levels

Effect levels 1

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Remarks:

There were no deaths up to the limit dose of 2000 mg/kg bw

Effect levels 2

Sex:

male/female

Dose descriptor:

LD0

Effect level:

>= 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Remarks:

There were no deaths up to the limit dose of 2000 mg/kg bw

Mortality:

There were no deaths up to the limit dose of 2000 mg/kg bw.

Clinical signs:

There were no test material-related clinical observations up to the limit dose of 2000 mg/kg bw.

Body weight:

There were no body weight changes up to the limit dose of 2000 mg/kg bw.

Gross pathology:

There were no gross necropsy findings up to the limit dose of 2000 mg/kg bw.

Other findings:

The test material induced very slight to slight erythema on eight rats. Ten sites had desquamation. There was no edema or other dermal findings. With the exception of desquamation noted for two females, all dermal irritation completely subsided by day 12 or earlier.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

As information was provided via a peer-reviewed assessment report, it can be considered as sufficiently reliable to assess the acute dermal toxicity of ethoxyquin towards rats. Ethoxyquin was found to be of a low order of acute toxicity following exposure of rats via the dermal route. On the basis of this study and in accordance with Annex VI of Commission Directive 2001/59/EC ethoxyquin shall not be classified with respect to acute dermal toxicity. The same applies to Regulation 1272/2008, as the LD50 is clearly above the limit dose for classification of 2000 mg/kg bw.

Executive summary:

In an acute dermal toxicity study (US EPA FIFRA Guideline §81-2, which is equivalent to OECD 402), groups of Crl:CD®BR albino rats (5/sex/dose) were dermally exposed to neat ethoxyquin for 24hours at a limit dose of 2000 mg/kg bw.  Animals then were observed for 14 days.

Dermal LD₅₀> 2000 mg/kg bw

Dermal LD₀≥ 2000 mg/kg bw

There were no deaths, test material-related clinical observations, body weight changes, or gross necropsy findings in this limit test. The test material induced very slight to slight erythema on eight rats.

Ethoxyquinis of low Toxicity and does not need to be classified according to Regulation 1272/2008.