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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 based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
1984-11-07 to 1984-12-12
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: This study report is classified as reliable with restrictions because it is an acceptable and a well-documented study report.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1985

Materials and methods

Test guideline
Qualifier:
equivalent or similar 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
Type:
Constituent
Test material form:
other: low viscosity hydrocarbon liquid
Details on test material:
Test substance (as identified in study report): API 83-08 (CAS# 64741-59-9)
Physical description: brown liquid
Gravity API: 24.2
Nitrogen, ppm: 312
Flash point: 142 °F
Viscosity at 40°C cST: 2.8

Paraffins 22.3%
Olefins 5.5%
Naphthenes 10.7%
Aromatics 61.5%
Saturates 33.0%

Distillation ASTM D86 Equivalent:
Initial Boiling Pt °F: 382
Boiling Pt Range (10-90%): 466-603
Final Boiling Pt °F: 642

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Hazleton Dutchland, Inc., Denver, Pennsylvania
- Age at study initiation: 5 to 6 weeeks old
- Weight at study initiation: 375 to 516 g
- Housing: individually housed
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 14 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 to 25°C
- Humidity (%): 42 to 66%
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 12 hours light/12 hours dark


IN-LIFE DATES: From: 1984-11-07 To: 1984-12-12

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
paraffin oil
Concentration / amount:
For the sensitising phase, test material (0.4 mL) was administered undiluted in paraffin oil. For the challenge phase, a 10% v/v dilution in paraffin oil was used (also at 0.4 mL).
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
paraffin oil
Concentration / amount:
For the sensitising phase, test material (0.4 mL) was administered undiluted in paraffin oil. For the challenge phase, a 10% v/v dilution in paraffin oil was used (also at 0.4 mL).
No. of animals per dose:
10 treated, 10 naive controls, 10 vehicle controls, 20 positive controls, 20 naive positive controls, and dose-range group of 6 guinea pigs were used.
Details on study design:
RANGE FINDING TESTS:
Six guinea pigs were used for the range-finding test with each animal exposed to two concentrations of test material. Sample was initially administered as undiluted, 25%, 50%, and 75% v/v solution in paraffin oil. Since irritation was observed at the lowest level, 1% anfd 10% v/v solutions were added to the range-finding study. No dermal irritation resulted at 1% v/v, and very slight dermal irritation was observed at 25% v/v. The two 10% applications produced very slight irritation in one instance and no response in the other. The 50%, 75%, and undiluted test material applications produced very slight to well-defined responses. Based on this study, the sensitising phase was chosen to be undiluted test material, and for the challenge phase, 10% v/v in paraffin oil was selected.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3 exposures
- Exposure period: 3 weeks
- Test groups: 0.4 millilitres of undiluted test material was applied to an adhesive pad (Hilltop Chamber, 25-millimetre diameter) and secured onto the clipped dorsal area (left anterior quadrant) of the animals with dental dam and elastoplast tape.
- Control group: naive controls did not receive any treatment, vehicle controls were dosed with paraffin oil undiluted at 0.4 millilitres, positive controls were dosed with 2,4-dinitrochlorobenzene at 0.3% w/v in 80% aqueous ethanol at 0.4 millilitres
- Site: clipped dorsal area
- Frequency of applications: once per week
- Duration: 6-hour duration after which patches and wrappings were removed and test sites were wiped with wet disposable paper towels
- Concentrations: undiluted


B. CHALLENGE EXPOSURE
- No. of exposures: one
- Day(s) of challenge: two weeks following the third sensitising dose
-Test groups: 0.4 millilitres of 10% v/v test material in paraffin oill was applied to an adhesive pad (Hilltop Chamber, 25-millimetre diameter) and secured onto the clipped dorsal area (right anterior quadrant) of the animals with dental dam and elastoplast tape.
-Control group: naive controls were dosed with the test material mixture in the same manner as the test group, vehicle controls were dosed with paraffin oil undiluted at 0.4 millilitres, positive controls were dosed with 2,4-dinitrochlorobenzene at 0.1% w/v in acetone at 0.4 millilitres
- Exposure period: single-exposure, 6-hour duration after which patches and wrappings were removed and test sites were wiped with wet disposable paper towels
- Site: naive site on the clipped dorsal area
- Concentrations: 10% v/v in paraffin oil
- Evaluation (hr after challenge): 24 and 48 hour after challenge dose

Challenge controls:
10 naive control animals and 10 naive positive controls were used.
Positive control substance(s):
yes
Remarks:
2,4-dinitrochlorobenzene (0.3% w/v in 80% aqueous ethanol)

Results and discussion

Positive control results:
Positive Control Group: Very slight to severe irritation was exhibited by all 20 animals. The reactions of 19 animals exceeded the highest
reaction observed in the naive positive control animals.

Naive Positive Control Group: Five of the 20 animals exhibited very slight erythema reactions while 15 exhibited no reaction.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
other: challenge
Group:
test group
Dose level:
10% v/v in paraffin oil
No. with + reactions:
0
Total no. in group:
9
Clinical observations:
One animal found dead on day 15; highest erythema score was 1, highest oedema score was 0
Remarks on result:
other: Reading: other: challenge. Group: test group. Dose level: 10% v/v in paraffin oil. No with. + reactions: 0.0. Total no. in groups: 9.0. Clinical observations: One animal found dead on day 15; highest erythema score was 1, highest oedema score was 0.
Reading:
other: challenge
Group:
negative control
Dose level:
10% v/v dilution
No. with + reactions:
0
Total no. in group:
9
Clinical observations:
Highest erythema score was 1, highest oedema score was 0
Remarks on result:
other: Reading: other: challenge. Group: negative control. Dose level: 10% v/v dilution. No with. + reactions: 0.0. Total no. in groups: 9.0. Clinical observations: Highest erythema score was 1, highest oedema score was 0.
Reading:
other: challenge
Group:
positive control
Dose level:
0.1% w/v dilution
No. with + reactions:
20
Total no. in group:
20
Clinical observations:
Highest erythema score was 3.5, highest oedema score was 3.0
Remarks on result:
other: Reading: other: challenge. Group: positive control. Dose level: 0.1% w/v dilution. No with. + reactions: 20.0. Total no. in groups: 20.0. Clinical observations: Highest erythema score was 3.5, highest oedema score was 3.0.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
At the challenge phase, the highest observed erythema score was 1 and the highest observed oedema score was 0. Based on the comparison between the test group and the naive control group, the test material is classified as not sensitising.
Executive summary:

In a dermal sensitisation study (Beuhler method), undiluted light catalytically cracked distillate was dermally applied to the clipped backs of 10 male Hartley albino guinea pigs during the induction phase, and a subsequent challenge dose was applied at a 10% v/v dilution of test substance in paraffin oil. Approximately 0.4 mL of test material was applied under occlusion for a 6 -hour exposure to one clipped area on each animal, once per week for 3 weeks during induction (total of three applications). The same test site was used for each application. Two weeks following the administration of the final induction application, a challenge dose (0.4 mL) was administered to the test groups on a different site and reactions recorded at 24 and 48 hours.

One control animal was found dead on day 16. Following the challenge application, very slight erythema was present in three of the nine surviving animals. These reactions did not exceed the highest reaction of the naïve control animals. The other test animals exhibited no reaction following challenge treatment. The naïve control group also exhibited very slight erythema in three of the control animals, indicating a lack of a sensitising response in the treated animals. Based on these results, light catalytically cracked distillate was not a skin sensitiser when tested using a closed patch technique in guinea pigs.

This study received a Klimisch score of 2 and is classified as reliable with restrictions because it is an acceptable and well documented study report.