Reaction mass of 1-methyl-3-(4-methyl-3-pentenyl)cyclohex-3-ene-1-carbaldehyde and 1-methyl-4-(4-methyl-3-pentenyl)cyclohex-3-ene-1-carbaldehyde

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 June, 1999 - 19 July, 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been performed according to OECD guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

(1993)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

(1996)

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

LLNA not available at time of testing

Test material

Test material information

Constituent 1

Reference substance name:

1-methyl-4-(4-methyl-3-pentenyl)cyclohex-3-ene-1-carbaldehyde

EC Number:

257-942-2

EC Name:

1-methyl-4-(4-methyl-3-pentenyl)cyclohex-3-ene-1-carbaldehyde

Cas Number:

52475-86-2

Molecular formula:

C14H22O

IUPAC Name:

1-methyl-4-(4-methylpent-3-en-1-yl)cyclohex-3-ene-1-carbaldehyde

Constituent 2

Reference substance name:

1-methyl-3-(4-methyl-3-pentenyl)cyclohex-3-ene-1-carbaldehyde

EC Number:

257-941-7

EC Name:

1-methyl-3-(4-methyl-3-pentenyl)cyclohex-3-ene-1-carbaldehyde

Cas Number:

52474-60-9

Molecular formula:

C14H22O

IUPAC Name:

1-methyl-3-(4-methylpent-3-en-1-yl)cyclohex-3-ene-1-carbaldehyde

Specific details on test material used for the study:

- Name of test material (as cited in study report): Precyclemone B
- Description: colorless to pale yellow liquid
- Analytical purity: 99.3 %
- Lot/batch No.: 9000320077
- Expiration date of the lot/batch: 25 March 2000
- Storage condition of test material: In the original container, in the refrigerator (range 2-8 °C), away from direct sun-light.

In vivo test system

Test animals

Species:

guinea pig

Strain:

other: Ibm: GOHI; SPF-quality (synonym: Himalayan spotted)

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: RCC Ltd., Biotechnology & Animal Breeding Division, Wölferstrasse 4, CH-4414 Füllinsdorf, Switzerland
- Age at study initiation: 5-7 weeks
- Weight at study initiation: 329-423 g
- Housing: Individually in Makrolon type-4 cages
- Diet: Pelleted standard Nafag Ecosan 845 25W4, guinea pig breeding/maintenance diet, ad libitum
- Water" Community tap water from Füllinsdorf, ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 (except on test days 12-13 where the temperature reached 26-28 °C)
- Humidity (%): 40 - 70 (values above 70% during cleaning process possible)
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

other: PEG 400

Induction 2

Concentration / amount:

5% for the intradermal induction and 100% for the epidermal induction.
1% for the challenge phase.

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

other: PEG 400

Challenge 2

Concentration / amount:

5% for the intradermal induction and 100% for the epidermal induction.
1% for the challenge phase.

No. of animals per dose:

Test animals: 10
Control animals: 5

Details on study design:

RANGE FINDING TESTS: (5 animals, weight between 304 and 472)

Intradermal injections:
Four intradermal injections (0.1 mL/site) of a 1:1 (v/v) mixture of FCA/physiological saline were made into the shaved neck of one animal. One week later intradermal injections (0.1 mL/site) were made into the clipped flank of the same animal at concentrations of 5, 3 and 1% of the test substance in PEG400. Dermal reactions were assessed 24 hours later.
- Results: A test substance concentration of 5% was selected for intradermal induction in the main study as mild reactions were observed.

Epidermal applications:
Four test substance concentrations were used (100, 75, 50 and 25%). The volume applied was approximately 0.2 mL per animal to the clipped flanks, using filter paper (3x3 cm). The patches were covered by a strip of aluminium foil and firmly secured by elastic plaster wrapped around the trunk and covered with impervious adhesive tape. The dressings were removed after an exposure period of 24 hours. An approved depilatory cream was used in order to visualize any resulting erythema. No highest non-irritating concentrations could be determined, therefore a second pretest was performed with concentrations 15, 10, 5 and 1%.
- Results: Test substance concentration of 100% was selected for the epidermal exposure as weak irritation was observed. 1% for epidermal challenge, highest non-irritant concentration.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 1

1) Intradermal injections on day 1:
- Site: scapular region.
Three pairs of intradermal injections:
1) 0.1 mL: FCA (50% in physiological saline)
2) 0.1 mL: test substance at a 5% concentration in PEG400 (control animals: 0.1 mL PEG400)
3) 0.1 mL: test substance at a 5% concentration in PEG400 in a 1:1 mixture of FCA and physiological saline (control animals: 1:1 mixture of PEG 400 in a 1: 1 mixture of FCA and physiological saline)

2) Topical application on day 8:
- Amount: 0.3 mL (control animals: 0.3 mL PEG 400) 100% test substance
- Area: approximately 8 cm^2
- Exposure period: 48 hours (occlusive)
- Readings: scores were rated 24 and 48 hours after patch removal

B. CHALLENGE EXPOSURE (all animals, with the 1% test substance and the vehicle)
- Day of challenge: day 22
- Exposure period: 24 hours (occlusive)
- Site: flank
- Amount: 0.2 mL
- Readings: scores were rated 24 and 48 hours after patch removal

OBSERVATIONS:
Viability/Mortality: Daily from delivery of the animals to the termination of the test.
Clinical signs (local/systemic): Daily from delivery of the animals to the termination of the test.
Skin reactions: At the times specified during the pretest, induction and challenge periods.
Body weights: At pretest I, II and acclimatization start, on test days 1, 8 (test article treatment start in the pretest II) and termination of the test.
Necropsy: Necropsy was performed in one animal of the pretest II which was found dead. No necropsies were performed in the second animal of pretest II and in the animals of the control and test group sacrificed at termination of the observation period nor in the animals of the pretest I sacirficed on test day 1 of the main study.

Challenge controls:

Not applicable.

Positive control substance(s):

yes

Remarks:

the results of the latest reliability check, performed in Dec 1998/Jan 1999 with 2-Mercaptobenzothiazole, are reported.

Results and discussion

Positive control results:

The latest reliability check shows a sensitisation rate of 90-100%

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

vehicle

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: vehicle. No with. + reactions: 0.0. Total no. in groups: 5.0.

Results 2

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

1%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 1%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Results 3

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

vehicle

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: vehicle. No with. + reactions: 0.0. Total no. in groups: 5.0.

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

1%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 1%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Any other information on results incl. tables

Skin effects after intradermal induction:

The expected and common findings were observed in the control and test group after the different applications using FCA intradermally and consisted of erythema, oedema, necrotizing dermatitis, encrustation and exfoliation of encrustation.

Skin effects after epidermal induction:

No erythema or oedema reactions were observed in the control group. In the test group, discrete/patchy erythema was observed in all animals at the 24 -hour reading and in 7 out of 10 animals in the 48 -hour reading after treatment with the undiluted test substance.

Skin effects after the challenge:

No skin reactions were observed in the control and test group animals when treated with either PEG 400 or with test article at 1% in PEG 400.

Viability/mortality/macroscpic findings:

One animal of the epidermal pretest II group was found dead on day 17. At necropsy, no findings were noted. The cause of death could not be established.

Clinical signs, systemic: No signs of systemic toxicity were observed in the animals.

Body weights: The body weight of the animals was within the range commonly recorded for animals of this strain and age.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In a guinea pig maximisation test method the potential of Precyclemone B for skin sensitisation was tested according to OECD 406 guideline and GLP principles, no sensitization was observed.

Executive summary:

In a guinea pig maximisation test method the potential of Precyclemone B for skin sensitisation was tested according to OECD 406 guideline and GLP principles.

Skin effects after intradermal induction: The expected and common findings were observed in the control and test group after the different applications using FCA intradermally and consisted of erythema, oedema, necrotizing dermatitis, encrustation and exfoliation of encrustation.

Skin effects after epidermal induction: No erythema or oedema reactions were observed in the control group. In the test group, discrete/patchy erythema was observed in all animals at the 24 -hour reading and in 7 out of 10 animals in the 48 -hour reading after treatment with the undiluted test substance.

Skin effects after the challenge: No skin reactions were observed in the control and test group animals when treated with either PEG 400 or with test article at 1% in PEG 400.

Based on these results Precyclemone B does not have to be classified and has no obligatory labelling requirement for sensitization by skin contact according to Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures.