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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
Study period:
07 Apr - 14 Apr 1998
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP guideline study with acceptable restrictions; analytical purity of test item was not given.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1998

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Version / remarks:
adopted in 1992
Deviations:
yes
Remarks:
analytical purity of test substance not specified
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): methyl laurate
- Substance type: Fatty acid methyl ester
- Physical state: liquid, colourless
- Analytical purity: not indicated by sponsor, treated as 100% pure
- Storage condition of test material: room temperature, protected from light

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Broekman Institute, The Netherlands
- Age at study initiation: 8 weeks
- Weight at study initiation: 1523, 1526 and 1611 g
- Housing: individually in cages with perforated floors
- Diet: approx 100 g/day of standard laboratory rabbit diet (LKK-20, pellet diameter 4 mm, Hope Farms, The Netherlands) and hay once a week
- Water: tap water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21
- Humidity (%): 50
- Air changes: approx. 15/hour
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:
semiocclusive
Preparation of test site:
other: clipped
Vehicle:
unchanged (no vehicle)
Controls:
other: not required, untreated sites of the same animal served as control
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL
Duration of treatment / exposure:
4 h
Observation period:
7 days
Reading time points: 1, 24, 48, 72 hours and 7 days
Number of animals:
3 males
Details on study design:
TEST SITE
- Area of exposure: dorsal skin, 6 cm²
- Type of wrap if used: Scotchpak-non-woven patch mounted on micropore taping secured with Coban elastic bandage

REMOVAL OF TEST SUBSTANCE
- Washing was done at the end of the 4 hour exposure period by means of a tissue moistened with water and subsequently a dry tissue

SCORING SYSTEM: Draize scoring system

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
other: mean over 24, 48 and 72h
Score:
2
Max. score:
4
Reversibility:
not fully reversible within: 7 days
Remarks on result:
other: scaliness was seen at day 7
Irritation parameter:
edema score
Basis:
animal #1
Time point:
other: mean over 24, 48 and 72h
Score:
1
Max. score:
4
Reversibility:
not fully reversible within: 7 days
Remarks on result:
other: see above
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
other: mean over 24, 48 and 72h
Score:
2
Max. score:
4
Reversibility:
not fully reversible within: 7 days
Remarks on result:
other: scaling and bald skin at the edges of the application site were seen at day 7
Irritation parameter:
edema score
Basis:
animal #2
Time point:
other: mean over 24, 48 and 72h
Score:
2.3
Max. score:
4
Reversibility:
not fully reversible within: 7 days
Remarks on result:
other: see above
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
other: mean over 24, 48 and 72h
Score:
2.3
Max. score:
4
Reversibility:
not fully reversible within: 7 days
Remarks on result:
other: scaling and bald skin at the edges of the application site were seen at day 7
Irritation parameter:
edema score
Basis:
animal #3
Time point:
other: mean over 24, 48 and 72h
Score:
1.3
Max. score:
4
Reversibility:
not fully reversible within: 7 days
Remarks on result:
other: see above
Irritant / corrosive response data:
Four hours exposure resulted in well defined or moderate to severe erythema and moderate edema in the treated skin areas of the three rabbits. Both, erythema and edema, had resolved within 7 days after exposure in all animals. However, at the end of the observation period, scaliness was noted in all animals and in addition bald skin at the edges of the application area was noted in two animals.

Any other information on results incl. tables

Table 1: Individual erythema scores at all reading time points:

Animal Number

1 h

24 h

48 h

72 h

7 days

Mean

(24, 48 and 72 h)

1

3

2

2

2

0

2.0

2

2

2

2

2

0

2.0

3

2

3

2

2

0

2.3

 

Table 2: Individual edema scores at all reading time points:

Animal Number

1 h

24 h

48 h

72 h

7 days

Mean

(24, 48 and 72 h)

1

3

2

1

0

0

1.0

2

3

3

2

2

0

2.3

3

3

2

1

1

0

1.3

Table 3: Additional findings

Animal Number

Additional skin findings with time points

Erythema at the edges of the application site

Scaliness

Bald skin at the edges of the application site

1

Yes (48 h and 72 h)

Yes (day 7)

No

2

Yes (48 h and 72 h)

Yes (day 7)

Yes (day 7)

3

Yes (72 h)

Yes (day 7)

Yes (day 7)

Applicant's summary and conclusion

Interpretation of results:
irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
CLP: Cat. 2, H315
DSD: Xi, R38