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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to the O.E.C.D. test guideline 429 with GLP compliance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report Date:
2011

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
GLP compliance:
yes
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
As per IUCLID Sections 1.1. 1.2. and 4.1.

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
The animals were sourced from Harlan Sprague-Dawley; Indianapolis, IN. and acclimated for 5 days. The mice were identified by tail marking/ and age cards. The weight range on the first day of dosing was 17.8 - 22.6 g. the female animals were maintained in polycarbonate boxes with bedding, 1-5 per cage. The animal room was set to maintain relative humidity of 30-70% with 10-12 air changes/hour and a temperature 21 ± 3°C. A 12-hour light/dark cycle was maintained. PMJ Feeds Jnc.TM Formulab #5008 was made available ad libitum, Sugar Land, Texas municipal water supply analyzed by TCEQ Water Utilities Division, was available ad libitum from automatic water system.

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, open
Vehicle:
other: Acetone/olive oil 3:1.
Concentration / amount:
25, 50 and 100% (undiluted).
Challengeopen allclose all
Route:
other: No challenge treatment, study is designed to evaluate induction only.
Vehicle:
other: Acetone/olive oil 3:1.
Concentration / amount:
25, 50 and 100% (undiluted).
No. of animals per dose:
5

Study design: in vivo (LLNA)

Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
25, 50 and 100% (undiluted)
No. of animals per dose:
5
Details on study design:
Five females were selected for each of three Test groups (Groups I - III). On Days 1, 2 and 3, each Test animal in its group received an open application of 25 uL of an appropriate dilution (25% or 50%) of the test substance, or 100% test substance undiluted, to the dorsum of both ears. The Vehicle Control group (5 females) was treated in the same way as test animals, but with vehicle alone (acetone:olive oil 3:1) instead of test substance.The Positive Control group (5 females) was treated with 80% aipha-hexylcinnamaldehyde in acetone:olive oil. All Test and Control animals were given a two-day rest period on Days 4 and 5. On Day 6 of the study, all Test and Control animals were injected in the tail vein with 250 uL of 0.01 M phosphate-buffered saline (PBS; Sigma, Lot 0451(8210, Exp Jul 2015), pH 7.4, containing 20 p.Ci of [methyl, 11, 2’-3H] Thymidine (PerkinsElmer, Lot 201103, Exp Mar 2012). Five hours after the injection, the aninials were sacrificed with an overdose of C02, the draining auricular lymph nodes were excised and pairs from each individual animal were processed.

A single cell suspension was prepared by gentle mechanical disintegration through 200 mesh stainless steel gauze. The cells were washed twice with an excess of PBS and precipitated with 5% trichloroacetic acid (TCA) at 4°C for 18 hours. The pellets were resuspended in 1 mL of TCA and transferred to 10 mL of scintillation fluid. Incorporation of tritiated thymidine was measured by liquid scintillation counting as disintegrations per minute (DPM) from the paired lymph nodes of each animal, and mean DPM/aninial was calculated for each group.


Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
No data

Results and discussion

Positive control results:
The positive control, 80% aipha-hexylcinnamaldehyde inducted a Stimulation Index of 7.7.

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: Group I 25% 10.1 Group ii 50% 9.4 Group iii 100% 9.8
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: Vehicle Control NA 966 Test Group I 25% 9763 Test Group II 50% 9042 Test Group III 100% 9431 Positive Control NA 7401

Applicant's summary and conclusion

Interpretation of results:
sensitising
Remarks:
Migrated information Criteria used for interpretation of results: other: Test guidelines and published liturature.
Conclusions:
The test substance is capable of the induction of a sensitization state under the conditions of the study. The Lowest Observed Adverse Effect Level (LOAEL) in the study was 25% of the test substance with a Stimulation Index of 10.1. Based on ECHA guidance (Chapter R.8. page 127) the test substance is considered to be a Moderate sensitizer. Based on the formula provided by ECHA (Chapter R8. page 128) and applying a 3-fold Assessment Factor (LOAEL to NOAEL) the DNEL dermal = approximately 21 ug/cm2.
Executive summary:

The test substance, 4,4'-Isopropylidenedicyclohexanol, oligomeric reaction products with 1-chloro-2,3-epoxypropane, was evaluated for its potential to induce a sensitzation state in an O.E.C.D. test guideline 429 mouse LLNA study. The test substance is capable of the induction of a sensitization state under the conditions of the study. The Lowest Observed Adverse Effect Level (LOAEL) in the study was 25% of the test substance with a Stimulation Index of 10.1. Based on ECHA guidance (Chapter R.8. page 127) the test substance is considered to be a Moderate sensitizer.