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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Observations on dermal irritation effects during an acute dermal toxicity study with occlusive application for 24 hrs at a test concentration similar to OECD Guideline 404; study acceptable for weight of evidence approach to waive a skin irritation study
Cross-reference
Reason / purpose:
reference to same study

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Hydroquinone: Acute and subchronic toxicity studies with emphasis on neurobehavioral and nephrotoxic effects.
Author:
Topping DC, Bernard LG, O'Donoghue JL, English JC
Year:
2007
Bibliographic source:
Food Chem Toxicol 45, 70 - 78
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report Date:
2001

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Dermal effects observed during acute dermal toxicity study
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): hydroquinone
- Analytical purity: at least 99%
- Lot/batch No.: no data
- Stability under test conditions: test substance assumed to be stable under test conditions

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Covance Reseaerch Products, Denver, PA, USA
- Age at study initiation: at least 3 mo
- Body weight at study initiation: males 2.329-2.492 kg, females 2.040-2.592 kg
- Fasting period before study: no
- Housing: single
- Diet: PMI #5325 ad libitum
- Water: ad libitum
- Acclimation period: 5 d

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.8-22.9
- Humidity (%): 47.8-70
- Air changes (per hr): not specified
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:
occlusive
Preparation of test site:
shaved
Vehicle:
other: moistened with water
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg
Duration of treatment / exposure:
24 h
Observation period:
14 d
Number of animals:
5 males and 5 females
Details on study design:
TEST SITE
- Area of exposure: dorsal skin
- % coverage: 10% of body surface
- Type of wrap if used: occlusive wrap (no further data)


REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes
- Time after start of exposure: 24 h


SCORING SYSTEM: only qualitative visual inspection of effects

Results and discussion

In vivo

Results
Irritation parameter:
other: qualitative assessment of skin irritation
Time point:
other: 24 h
Score:
ca. 0
Remarks on result:
other: Score of 0 assumed as default value for absence of adverse skin effects
Irritant / corrosive response data:
No adverse dermal effects reported

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: not specified
Conclusions:
Based on the absence of any dermal effects at the application site, there was no indication of skin irritation in rabbits during a dermal toxicity study with test concentrations comparable to those used for skin irritation studies. A more severe test condition with a 24-hour occlusive application was applied than is usual for skin irritation studies according to OECD Guideline 404 .
Executive summary:

Groups of 5 male and 5 female rabbits were exposed to HQ moistened with water for 24 h under an occlusive dressing during a dermal toxicity study and skin findings were reported qualitatively (no skin scoring system applied to describe findings). These test conditions deviate from OECD Guideline 404 which requests a 4-h semi-occlusive exposure. However, as the test concentrations of 27-36 mg/cm2, which were estimated based on the applied dose of 2000 mg/kg bw, are comparable to the 30 mg/cm2 requested by OECD Guideline 404, this study can be used for the assessment of skin irritation. No adverse dermal effects were reported indicating the absence of an irritating potential of pure HQ (no vehicles used) under the conditions of this test.