1,3- AND 1,4-CYCLOHEXANDICARBOXYALDEHYDE

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP/Guideline Study

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

482-020-3

EC Name:

-

Molecular formula:

C8H12O2

IUPAC Name:

cyclohexane-1,3-dicarbaldehyde; cyclohexane-1,4-dicarbaldehyde

Test material form:

gas under pressure: refrigerated liquefied gas

Details on test material:

- Name of test material (as cited in study report): unoxolTM 3 ,4 Dialdehyde
- Isomers composition: +/- 53% 1,3-cyclohexanedicarboxdialdehyde (CAS 55309-54-1);
+/- 47% 1,4-cyclohexanedicarboxdialdehyde (CAS 33424-83-8)
- Lot/batch No.: 200502771-6M
- Expiration date of the lot/batch: 31 December 2006
- Stability under test conditions: Stable
- Storage condition of test material: In refrigerator (2-8°C) in the dark under nitrogen

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River France, L'Arbresle Cedex, France
- Age at study initiation: Approximately 10 weeks old
- Housing: groups housed in Macrolon cages
- Diet (e.g. ad libitum): Free access to standard pelleted laboratory diet (from Altromin (code VRF 1), Lage, Germany)
- Water (e.g. ad libitum): Free access to tap water
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18.8-23.5°C
- Humidity (%): 33-77%
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, open

Vehicle:

propylene glycol

Induction 2

Concentration / amount:

50, 100%

Challenge

Concentration / amount:

50, 100%

No. of animals per dose:

1

Study design: in vivo (LLNA)

Vehicle:

propylene glycol

Concentration:

5%, 25%, and 50% of test substance

No. of animals per dose:

5

Details on study design:

Three groups of five experimental animals were treated with test substance concentrations of
5%, 25% or 50% on three consecutive days, by open application on the ears. Five vehicle control animals were
similarly treated, but with vehicle alone (Propylene glycol). Three days after the last exposure, all animals were
injected with 3H-methyl thymidine and after five hours the draining (auricular) lymph nodes were excised.
After precipitating the DNA of the lymph node cells, radioactivity measurements were performed. The activity
was expressed as the number of Disintegrations Per Minute (DPM) and a stimulation index was subsequently
calculated for each group.

Positive control substance(s):

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

Statistics:

DPM values are presented for each animal and for each dose group. A Stimulation Index (SI) is calculated for each group. The SI is the ratio of the DPM/group compared to DPM/vehicle control group.

Results and discussion

Positive control results:

The six month reliability chech with Hexylcinnamic aldehyde indicates that the Local Lymph Node Assay as performed at NOTOX is an appropriate
model for testing for contact hypersensitivity.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: see Remark

Remarks:

The SI values for the substance concentrations 5, 25, and 50% were 7.6, 48.0, and 54.2 respectively. These results show that the test substance elicited an SI ≥ 3. The data showed a dose-response and the EC3 value was established to be between 0 and 5%

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Mean DPM/animal values for the experimental groups treated with test substance concentrations 5, 25, and 50% were 1484, 9339, and 10539 respectively. The mean DPM/animal value for the vehicle control group was 195.

Any other information on results incl. tables

TABLE 1: SKIN REACTIONS AFTER 3RD INDUCTION AND RELATIVE SIZE NODES

		Day 3				Day 6
Group	Animal	skin grading dorsal surface ear				size nodes
Treatment	Number	left		right		left	right
		erythema	oedema	erythema	oedema
1	1	0	0	0	0	n	n
Vehicle*	2	0	0	0	0	n	n
Control	3	0	0	0	0	n	n
	4	0	0	0	0	n	n
	5	0	0	0	0	n	n
2	6	1	0	1	0	n	n
5% test	7	0	0	1	0	n	n
substance	8	0	0	0	0	n	n
	9	0	0	0	0	n	n
	10	1	0	0	0	n	n
3	11	1	0	2	0	+	+
25% test	12	1	0	1	0	+	+
substance	13	1	0	1	0	+	+
	14	1	0	1	0	+	+
	15	1	0	1	0	+	+
4	16	1	0	1	0	++	++
50% test	17	2	0	2	0	++	++
substance	18	1	0	2	0	+	++
	19	2	0	2	0	++	++
	20	1	0	2	0	+	++

n: considered to be normal

+: enlarged

* Vehicle: Propylene glycol

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

According to the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) of the United Nations (New York and Geneva, 2003), Unoxol 3,4 Dialdehyde should be classifed as a skin sensitizer (Category 1).

Executive summary:

In the main study, three groups of five experimental animals were treated with test substance concentrations of 5%, 25%, or 50% on three consecutive days, by an open application on the ears. Five vehicle control animals were similarly treated, but with vehicle alone(Propylene glycol). Three days after the last exposure, all animals were injected with 3H-methyl thymidine and after five hours the draining (auricular) lymph nodes were excised. After precipitating the DNA of the lymph node cells, radioactivity measurements were performed. The activity was expressed as the number of Disintegrations Per Minute (DPM) and a stimulation index was subsequently calculated for each group.

Mean DPM/animal values for the experimental groups treated with test substance concentrations 5, 25, and 50% were 1484, 9339 and 10539 respectively. The mean DPM/animals value for the vehicle control group was 195.

The SI values calculated for the substance concentrations 5, 25, and 50% were 7.6, 48.0, and 54.2 respectively.

The results show that the test substance elicited an SRI ≥ 3. The data showed a dose-response and the EC3 value was established to be between 0 and 5%.

The six month reliability check with Hexylcinnamic aldehyde indicates that the Local Lymph Node Assay as performed at NOTOX is an appropriate model for testing for contact hypersensitivity. Based on these results:

- according to the recommendations make in the test guidelines, Unoxol 3,4 Dialdehyde would be regarded as a skin sensitizer.

- according to the globally Harmonized System of Classification and Labeling of Chemicals (GHS) of the United Nations (New York and Geneva, 2003), Unoxol 3,4 Dialdehyde should be classified as a skin sensitizer (Category 1).

- according to the EC criteria for classification and labeling requirements for dangerous substances and preparations (Council Directive 67/548/EEC) Unoxol 3,4 Dialdehyde should be labeled as: may cause sensitization by skin contact (R 43).