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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
1980-11-18 to 1980-12-27
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: This study was classified as reliable without restrictions because it was conducted according to OECD guideline 406.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1982
Report Date:
1982

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
GLP compliance:
yes
Type of study:
Buehler test
Justification for non-LLNA method:
The first-choice method according to REACH Annex VII §8.3, the Murine Local Lymph Node Assay, is known to give false positive results with hydrocarbon substances.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Read Across to Other Lubricant Base Oils
- Name of test material (as cited in study report): API 78-9 Solvent dewaxed light paraffinic oil, CAS No. 64742-56-9
- Molecular weight (if other than submission substance): 322
- Substance type: Other Lubricant base oil (Sufficiently refined, IP 346 <3%)
- Physical state: Liquid
- Analytical purity: Not reported
- Composition of test material, percentage of components: Saturates - 88.3%; Aromatics - 11.3%
- Purity test date: Not reported
- Lot/batch No.: Not reported
- Expiration date of the lot/batch: Not reported
- Stability under test conditions: Not reported
- Storage condition of test material: Room temperature
- Other:
Specific gravity 60/60: 0.8490
Viscosity: 64.2 SUS @ 100°F

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: CAMM Research Institute (Wayne, New Jersey)
- Age at study initiation: Not reported
- Weight at study initiation: Not reported
- Housing: Individually in polycarbonate cages
- Diet (e.g. ad libitum): Purina Guinea Pig Chow® ad libitum
- Water (e.g. ad libitum): Fresh water ad libitum
- Acclimation period: 14 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): Not reported
- Humidity (%): Not reported
- Air changes (per hr): Not reported
- Photoperiod (hrs dark / hrs light): Not reported


IN-LIFE DATES: From: 1980-11-04 To: 1980-12-27

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
Dose Titration - 0.1, 0.5, 1.0, and 2.0 mL
Induction and Challenge - 1.0 mL
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
Dose Titration - 0.1, 0.5, 1.0, and 2.0 mL
Induction and Challenge - 1.0 mL
No. of animals per dose:
10 male guinea pigs/dose
Details on study design:
RANGE FINDING TESTS: A range-finding study was conducted by administering API 78-9 at doses of 0.1, 0.5, 1.0, and 2.0 mL to 3 guinea pigs with the first two doses administered to one animal at separate sites. The test material was applied to 1 square inch guaze pads backed by plastic occlusive wrap held in place by elastic tape. The test material was applied for 6 hours and then removed. Thereafter, the test sites were scored for edema and erythema based on the method of Draize and the highest non-irritating dose was used in the subsequent main study.


MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 10
- Exposure period: 6 hours
- Test groups: single test group with 10 male guinea pigs
- Control group:not utilized
- Site: Either side of thorax, half-way down from the shoulders to the hips
- Frequency of applications: 3/week for 3 weeks
- Duration: 3 weeks
- Concentrations: 1.0 mL


B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: ~ Day 35
- Exposure period: 6 hours
- Test groups: single test group with 10 male guinea pigs
- Control group: not utilized
- Site: Right side of thorax, half-way down from the should
- Concentrations: 1.0 mL
- Evaluation (hr after challenge): 24 hours post challenge

Challenge controls:
Not utilized
Positive control substance(s):
yes
Remarks:
0.5 mL of a 0.05% w/v solution of chlorodinitrobenzene in ethanol

Results and discussion

Positive control results:
At challenge, 9 of 10 animals in the positive control group exhbited very slight erythema (1) while 1 animals exhibited well-defined erythema (2) 24 hours post-exposure. There was no edema observed at challenge in any animal in the positive control group.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
1.0 mL
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None reported
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 1.0 mL. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: None reported.
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
0.5 mL
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
None reported
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: positive control. Dose level: 0.5 mL. No with. + reactions: 10.0. Total no. in groups: 10.0. Clinical observations: None reported.
Reading:
1st reading
Group:
negative control
Remarks on result:
not measured/tested

Any other information on results incl. tables

Table 1. Mean Erythema and Edema Scores for Treatments and Challenge

Parameter

Mean Score

Difference (Mean)

T-Value

Degrees of Freedom

Two Tail Probability

API 78-8

Erythema

 

 

 

 

 

    Sensitizing

0.18

0.18

3.86

9

0.004+

    Challenge

0.00

Edema

 

 

 

 

 

    Sensitizing

0.00

0.00

No T value (SD = 0)

9

 

    Challenge

0.00

Positive Control

Erythema

 

 

 

 

 

    Sensitizing

0.47

-0.63

-7.24

9

0.000*

    Challenge

1.10

Edema

 

 

 

 

 

    Sensitizing

0.05

0.05

3.00

9

0.015+

    Challenge

0.00

*Statistically significant difference (p<0.05)

+Statistically significant difference, but challenge mean is less than the sensitizing mean.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
Under the conditions of the test, Solvent dewaxed light paraffinic oil is considered non-sensitizing.
Executive summary:

Read across justification

The physical and chemical properties of foots oils are comparable to the other lubricant base oil intermediate streams from which they are derived. Hence their health effects are also similar to those of other lubricant base oils, and the conclusions of the hazard assessment for other lubricant base oils also apply to foots oils.

In a guinea pig skin sensitization test, 10 male Hartley guinea pigs were induced and subsequently challenged by topical administration of Solvent dewaxed light paraffinic oil.

Initially 3 guinea pigs were tested with 0.1, 0.5, 1.0, and 2.0 mL of Solvent dewaxed light paraffinic oil in a range-finding study. Based on the results of the range-finding study, the 1.0 mL dose was selected for the subsequent induction and challenge phases of the experiment. 24 hours prior to exposure, the guinea pigs were shaved with a clipper blade on either side of the thorax from the shoulders down till the hips. 1.0 mL of the test material was applied to 1 square inch guaze sponges backed by an occlusive plastic wrap that was then kept in contact with the skin for 6 hours with elastic tape. 24 hours after patch removal, the animals were scored for irritation based on the method of Draize. The test material was subsequently applied (following the same procedure) three times per week for three consecutive weeks following which the animals were held for a period of two weeks and then challenged with 1.0 mL of Solvent dewaxed light paraffinic oil. the procedure followed for the challenge phase was the same as that employed during induction. A positive control group of 10 male guinea pigs was dosed with 0.5 mL of 0.05% w/v solution of chlorodintrobenzene in ethanol and data generated was analyzed using the student's t test.

A significant difference was observed in the mean erythema scores between the induction (sensitizing) and challenge phases. However, the challenge mean scores were zero for both parameters observed (erythema and edema) indicating that Solvent dewaxed light paraffinic oil is not a sensitizer. In the positive control group, challenge erythema scores were significantly higher than those observed in the induction phase indicating that chlorodintrobenzene is a dermal sensitizer.

Under the conditions of this study, Solvent dewaxed light paraffinic oil is not considered to be a dermal sensitzer.

This study was classified as reliable without restrictions because it was conducted according to OECD guideline 406.