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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: This study is classified as reliable without restriction because it is an acceptable, well-documented study report.
Cross-reference
Reason / purpose for cross-reference:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986
Report date:
1986

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
yes
Remarks:
skin was abraded; exposure was over 24 hours instead of 4 hours
Principles of method if other than guideline:
Method: Draize Test
GLP compliance:
yes

Test material

Constituent 1
Reference substance name:
64742-53-6
Cas Number:
64742-53-6
IUPAC Name:
64742-53-6
Constituent 2
Reference substance name:
Hydrotreated light naphthenic oil, insufficiently refined, IP346>3%
IUPAC Name:
Hydrotreated light naphthenic oil, insufficiently refined, IP346>3%
Test material form:
other: Oily liquid
Details on test material:
- Name of test material (as cited in study report): hydrotreated light naphthenic oil, CAS No. 64742-53-6
-Substance Type: Lubricant base oil (insufficiently refined, IP 346 > 3wt%)
- Physical state: Liquid

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Age at study initiation: young adults
- Weight at study initiation: range of 2,502 to 2,815 grams
- Housing: animals were housed individual in screen-bottom cages
- Diet: Purina Certified Rabbit Chow #5322 provided ad libitum
- Water: water provided ad libitum
- Acclimation period: fourteen days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 to 24°C
- Humidity (%): 62 to 78%
- Photoperiod (hrs dark / hrs light): 12 hours light/12 hours dark


IN-LIFE DATES: From: 1984-09-05 To: 1984-10-11

Test system

Type of coverage:
occlusive
Preparation of test site:
other: abraded and shaved
Vehicle:
other: None - undiluted
Controls:
no
Amount / concentration applied:
0.5 mL
Duration of treatment / exposure:
24 hour(s)
Observation period:
Animals were observed for erythema and oedema after the 24 hour exposure period, at 72 and 96 hours, and 7 and 14 days.
Number of animals:
6
Details on study design:
TEST SITE
- Area of exposure: hair was clipped from the back and flank of each rabbit
- Type of wrap if used: occlusive, covered with a gauze patch and secured with paper tape and overwrapped with Saran Wrap and Elastoplast tape.


REMOVAL OF TEST SUBSTANCE
- Washing (if done): the area was wiped clean with wet disposable towels
- Time after start of exposure: 24 hours


SCORING SYSTEM: Draize

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
primary dermal irritation index (PDII)
Time point:
other: 24 and 72 hours
Score:
5.4
Irritation parameter:
erythema score
Remarks:
Intact skin
Basis:
mean
Time point:
other: 24 to 72 hours
Score:
2.67
Irritation parameter:
edema score
Remarks:
Intact skin
Basis:
mean
Time point:
other: 24 to 72 hours
Score:
2.67
Irritation parameter:
erythema score
Remarks:
Abraded skin
Basis:
mean
Time point:
other: 24 to 72 hours
Score:
2.67
Irritation parameter:
edema score
Remarks:
Abraded skin
Basis:
mean
Time point:
other: 24 to 72 hours
Score:
2.83
Irritant / corrosive response data:
The primary dermal irritation score was 5.4. Signs of erythema and oedema were seen at all across all observation periods, except day 14 day, at both the intact and abraded sites.

Any other information on results incl. tables

Average Irritation scores are given below: 

ObservationPeriod

Erythema

OEdema

Irritation Score

Intact

Abraded

Intact

Abraded

24 hrs

2.3

2.3

2.7

2.7

5.0

72 hrs

3.0

3.0

2.5

3.0

5.8

96 hrs

2.7

2.8

2.7

3.0

5.6

7 days

1.3

2.2

0.8

1.7

3.0

14 days

0

0

0

0

0



Primary dermal irritation index:  5.4

Applicant's summary and conclusion

Interpretation of results:
Category 2 (irritant)
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The test material is classified as a mild irritant by the study report.
Executive summary:

In a primary dermal irritation study six male New Zealand White rabbits were dosed with 0.5 mL of hydrotreated light naphthenic oil on two areas of exposed skin, one shaved and one abraded. The treated area was then covered with an occlusive dressing. After 24 hours, the dressing was removed and the treated skin was wiped to remove any residue of test material. The degree of erythema and oedema was recorded according to the Draize scale. A second reading of skin responses was made at 72 hours and again at 96 hours, and 7 and 14 days.

Results of the 24 and 72-hour readings were used to determine the Primary Irritation Index. The primary dermal irritation score was 5.4. Signs of erythema and oedema were seen at all across all observation periods, except day 14 day, at both the intact and abraded sites. The mean erythema and oedema scores for the 24 to 72 hour period were 2.67 and 2.67 for intact skin. For abraded skin, the mean erythema and oedema scores for the 24 to 72 hour period were 2.67 and 2.82, repsectively, for abraded skin. This study was performed during 24 hours rather than 4 hours recommended by the current OECD guidelines. Consequently, the result from a shorter exposure time will likely not cause classification of the category. Lubricant base oils (IP 346 > 3 wt %) are not skin irritants based on a weight of evidence approach.

This study received a Klimisch score of 2 and is classified as reliable without restriction because it is an acceptable, well-documented study report.