3-{[2-(2-hydroxyethoxy)ethyl]imino}-2,2-dimethylpropyl dodecanoate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008-09-10 to 2008-10-27

Reliability:

1 (reliable without restriction)

Cross-reference

Cross-reference 1

Reason / purpose:

reference to same study

Cross-reference 2

Reason / purpose:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report Date:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Version / remarks:

2002

Deviations:

no

Test guideline 2

Qualifier:

according to

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Version / remarks:

2004

Deviations:

no

Principles of method if other than guideline:

NA

GLP compliance:

yes (incl. certificate)

Type of study:

mouse local lymphnode assay (LLNA)

Test material

Reference

Name:

Unnamed

Type:

Constituent

Type:

Constituent

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report): Aldimine 2
- Physical state: liquid, almost colourless / faint yellow
- Analytical purity: 96.7 %
- Lot/batch No.: ub2.398B/11
- Expiration date of the lot/batch: 04 August 2011
- Stability under test conditions: stable for at least 3 years
- Storage condition of test material: room temperature, closed bottle

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Hungarian Supplier: WOBE Kereskedelmi Kft., H-1164, Budapest, Garmada u. 10.

- Age at study initiation: Young adult, 9-10 weeks old, age-matched within one week
- Housing: Individual caging
- Diet (e.g. ad libitum): ssniff® SM R/M-Z+H , ad libitum
- Water (e.g. ad libitum): tap water from municipal supply, ad libitum
- Acclimation period: 21 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 °C
- Humidity (%): 30 - 70 %
- Air changes (per hr): 8-12 air exchange/hour by central air-condition system.
- Photoperiod (hrs dark / hrs light): 12 hours daily, from 6.00 a.m. to 6.00 p.m.

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

25;50;100 % (w/v) (25µl)

No. of animals per dose:

4

Details on study design:

In the main assay sixteen female CBA/Ca mice were allocated to four groups of four animals each:
- three groups received the appropriate formulation of Sika Hardener LG at concentrations of 100 %*, 50 % or 25 %,
- the negative control group received the vehicle (AOO).

Each substance was applied on the external surface of each ear (25 µl/ear) of the animals for three consecutive days (Day 1, 2 and 3). There was no treatment on Days 4, 5 and 6. On Day 6, the cell proliferation in the local lymph nodes was measured by incorporation of tritiated methyl thymidine (3HTdR) and the obtained values were used to calculate stimulation indices (SI).

Positive control substance(s):

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

Statistics:

NA

Results and discussion

Positive control results:

The positive control substance α-Hexylcinnamaldehyde (HCA) was examined at a concentration of 25 % in the relevant vehicle. A significant lymphoproliferative response (SI ≥ 3) was noted for HCA with stimulation index value of 11.3 in accordance with our historical data, demonstrating the test reliability.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: see Remark

Remarks:

A significant lymphoproliferative response (SI >= 3) was noted for Sika Hardener LG at a concentration of 100 %. The stimulation index values were 5.0, 2.6 and 1.4 at concentrations of 100 % (undiluted test item), 50 % and 25 %, respectively. The stimulation index values were compatible with the conventional biological dose-response.

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: NA

Any other information on results incl. tables

clinical signs and mortality:

No mortality or signs of systemic toxicity were observed during the study. No significant effects were observed on animal body weights. No irritation or other cutaneous effect was observed in any of the groups treated.

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information

Conclusions:

Under the conditions of the present assay Sika Hardener LG, tested as supplied and in a suitable vehicle, was shown to have weak sensitisation potential (weak-sensitiser) in the Local Lymph Node Assay.

Executive summary:

A LLNA test was conducted with Sika Hardener LG. No mortality or signs of systemic toxicity were observed during the study. No significant effects were observed on animal body weights. No irritation or other cutaneous effect was observed in any of the groups treated.

The EC3 value (the theoretical concentration of the test item in the test solution, leading a three fold increase of lymph node cell proliferation over the control) was estimated by linear interpolation using the reported SI values and the corresponding concentrations immediately above and below the SI value of 3. The estimated EC3 value of Sika Hardener LG was 58.3 % in this LLNA. On the basis of published classification of contact allergens according to their potency Sika Hardener LG can be ranked among weak sensitisers (100 >= EC3 (%) >=10).

Under the conditions of the present assay Sika Hardener LG was shown to have weak sensitisation potential (weak-sensitiser) in the Local Lymph Node Assay.