Methanal, reaction products with 1,3-bis(aminomethyl)benzene and hydroxybenzene

Skin sensitisation

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 LLNA with GLP compliance.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

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

Test material information

Constituent 1

Reference substance name:

Reaction products of 2-methylimidazole and 2,2'-[(1- methylethylidene)bis(4,1-phenyleneoxymethylene)]bisoxirane

EC Number:

701-436-0

Molecular formula:

(C15H16O2.C4H6N2.C3H5ClO)x

IUPAC Name:

Reaction products of 2-methylimidazole and 2,2'-[(1- methylethylidene)bis(4,1-phenyleneoxymethylene)]bisoxirane

Test material form:

other: Liquid at room temperature.

Details on test material:

As per IUCLID5 Sections 1.1. 1.2. 1.3. and 4.1.

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

The experimental animals were purchased from Harlan Sprague-Dawley; Indianapolis, IN and weighted 20.1 - 24.5 gm at Experimental initiation. The mice were housed in polycarbonate boxes with bedding 1-5 per cage. The animal room was operated at 19-22°C with a relative humidity range of 49-91% and a 10-12 air changes/hour with 12-hour light/dark cycle. PMI Feeds Inc.TM Formulab #5 008 was available ad libitum and
Municipal water supply analyzed by TCEQ Water Utilities Division was available ad libitum from automatic water system.

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

25, 50 and 100 % v/v in 80% acetone:20% olive oil

No. of animals per dose:

5

Details on study design:

Five female mice were selected for each of three Test groups. 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) instead of test substance. The Positive Control group (5 females) was treated with 80% alpha-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 1uL of 0.01 M phosphate-buffered saline (PBS) pH 7.4 at 25°C per manufacturer, containing 20 uCi of {methyl-3H1 Thymidine. Five hours after the injection, the animals were sacrificed with an overdose of CO2, 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% trich1oroacetic acid 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/animal was calculated for each group.

Individual body weights were recorded on Day 1 prior to dosing, and Day 6, prior to injection. All Test and Control animals were observed daily for clinical signs of toxicity and any signs of excessive irritation at the test site.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

Not conducted.

Results and discussion

Positive control results:

The mean Stimulation Index (SI) or Test/Vehicle Control DPM Ratio was 6.8.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: Test Substance 25% 6.8 Test Substance 50% 3.2 Test Substance 100% 10.3 Positive control 6.8

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: see Remark

Remarks:

Group Mean DPM Vehicle control 33494 Test Substance 25% 23786 Test Substance 50% 11128 Test Substance 100% 35829 Positive Control 23807

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information Criteria used for interpretation of results: other: Peer reviewed publication

Conclusions:

The test substance is a skin sensitizer under the conditions of the study inducing a SI of > 3-fold at all three dose levels. The Estimated Concentration (EC) is 10-11%. Therefore, the test substance is a weak to moderate skin sensitizer.

Executive summary:

The test substance, Formaldehyde, polymer with 1,3 -benzenedimethanamine and phenol was evaluated dermal sensitizing potential in an O.E.C.D. test guideline 429 mouse LLNA study. The test substance is a skin sensitizer under the conditions of the study inducing a SI of > 3-fold at all three dose levels. The Estimated Concentration (EC) is 10-11%. Therefore, the test substance is a weak to moderate skin sensitizer.