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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation / corrosion, other
Remarks:
in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant, guideline study, available as unpublished report, no restrictions, fully adequate for assessment

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report Date:
1989

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): DCPD 75%
- Physical state: clear, yellow coloured liquid
- Analytical purity: not reported
- Composition of test material, percentage of components: endo dicyclopentadiene: 71.1, exo dicyclopentadiene: 0.8, m-bicyclozonadiene: 1.4, CPD-MCPD codimers: 15.2, tricyclopentadiene: 0.3, CPD-butadiene codimer: 1.3, CPD-piperylene codimer: 0.3, CPD-isoprene codimer: 0.3, benzene: <0.1, misc.hydrocarbons: balance.
- Lot/batch No.: PD Sample 1
- Stability: Not determined
- Specific gravity (15/15°C) 0.9811
- Other: Gardner colour: 4+; total sulfur: 60 ppm (w/w); flashpoint 39°C pct (w/w)

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: David Percival Ltd., Moston, Sandbach, Cheshire, UK
- Age at study initiation: 12-16 weeks
- Weight at study initiation: 2.22-2.54kg
- Housing: Individually in suspended metal cages
- Diet: Rabbit Diet ad libitum (Preston Farmers Ltd., New Leake, Boston, Lincolnshire, UK)
- Water: Mains water ad libitum
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 16-22°C
- Humidity: 54-67%
- Air changes (per hr): Approximately 15/hour
- Photoperiod: 12 hrs dark / 12 hrs light):

IN-LIFE DATES: From: 9 November 1988 To: 16 November 1988

Test system

Type of coverage:
semiocclusive
Preparation of test site:
other: clipped
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
0.5 mL
Duration of treatment / exposure:
4 hours
Observation period:
7 days
Number of animals:
3
Details on study design:
TEST SITE
- Area of exposure: 2.5 x 2.5 cm
- % coverage: not specified
- Type of wrap if used: gauze patch held in place with surgical adhesive tape under a Tubigrip corset

REMOVAL OF TEST SUBSTANCE
- Washing (if done): swabbed with water
- Time after start of exposure: 4 hr after application

SCORING SYSTEM: Draize scale

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
mean
Time point:
other: 24, 48 & 72 h
Score:
2
Max. score:
4
Reversibility:
fully reversible within: 7 days.
Remarks on result:
other: possible hyperkeratinisation at 7 days in all 3 animals.
Irritation parameter:
edema score
Basis:
mean
Time point:
other: 24, 48 & 72 h
Score:
2.3
Max. score:
4
Reversibility:
fully reversible within: 7 days

Any other information on results incl. tables

Skin irritation scores according to the Draize scheme

Time

Erythema (Test/Control sites)

Oedema (Test/Control sites)

 Animal number

34F

43F

80M

34F

43F

80M

after 1 hour

1

2

1

1

2

1

after 24 hours

2

2

2

4

4

3

after 48 hours

2

2

2

2

2

1

after 72 hours

2

2

2

2

2

1

mean scores 24-72h

2

2

2

2.6

2.6

1.7

Overall mean score (24-72 h)

2

2.3

Well-defined erythema persisted at all treated skin sites at 24, 48 and 72 hour observations. Signs of possible hyperkeratinisation were noted on day 7. No oedema was noted on day 7. No other adverse dermal reactions were noted during the study.

Applicant's summary and conclusion

Interpretation of results:
moderately irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
In a skin irritation study with dicyclopentadiene 75% in rabbits, overall mean scores (24, 48 & 72 hr) were 2 for erythema and 2.3 for oedema. Dicyclopentadiene 75% was therefore considered to be a moderate irritant to rabbit skin.
Executive summary:

Skin irritation was assessed in a group of 3 New Zealand white rabbits. 0.5 mL of dicyclopentadiene 75% was applied to an area of clipped, intact skin under a semi-occlusive dressing for 4 hours. Animals were observed at 1 and 4 hours after removal of the patch and then daily for 7 days. Well-defined erythema and slight to severe oedema was present at skin sites of all rabbits at 24, 48 and 72 hour observations. On day 7 no oedema was noted but there were signs of possible hyperkeratinisation. No other adverse dermal reactions were noted during the study. The overall mean scores (24, 48 & 72 hr) were 2 for erythema and 2.3 for oedema, and the mean oedema score exceeded 2.3 for two of the three animals. DCPD 75% was a therefore considered a moderate irritant to rabbit skin and, according to EEC labelling regulations, the symbol "Xi" and risk phrase R38 "IRRITATING TO SKIN" are required.