Phenol, 2-methoxy-, reaction products with 2,2-dimethyl-3-methylenebicyclo[2.2.1]heptane, hydrogenated

Endpoint summary

Description of key information

LLNA (GLP and OECD 429 guideline study) (Gerbeix C., 2009): ambigous (SI= 11 at 25% but irritating effects are also observed).

Magnusson and Kligman test (GLP and OECD 406 guideline study) (Totok-Batho, M., 2015): The test item was shown to have no sensitisation potential.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Remarks:

Type of sensitisation: skin sensitisation in the guinea pig using Magnusson and Kligman method

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 03 August 2015 to 11 December 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Well documented GLP study performed according to OECD Guideline 406. Variations from the relative humidity were observed during the study. These deviations were considered to have no impact on the animal health or on the outcome of the study and interpretation of the results due to their low magnitude.

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

variations from relative humidity; no impact on animal health or outcome of the study and interpretation of results

GLP compliance:

yes (incl. QA statement)

Remarks:

22 september 2015

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

An LLNA test has been done showing ambiguous results due to irritation and no conclusion can be drawn. Since the substance is viscous the mice were scratched ears.

Species:

guinea pig

Strain:

other: LAL/HA/BR

Sex:

female

Details on test animals and environmental conditions:

- Source: LAB-ÁLL Bt. Budapest, 1174 Hunyadi u. 7., Hungary
- Justification of strain: The guinea pig is the standard species used for skin sensitisation studies.
- Body weight range at randomisation: 274-305 g
- Age of animals at arrival: young adult, 5 weeks at onset of the treatment
- Acclimatization time: 6 days
- Cage type: animals were housed in macrolon cages size IV (24x56x33.5 cm), with 5 animals/cage to allow socialization
- Diet: ad libitum
- Water: ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.1 - 23.0 °C
- Humidity (%): 34 - 79%
- Air changes (per hr): 15-20 air exchange/hour
- Photoperiod (hrs dark / hrs light): 12/12

Route:

intradermal

Vehicle:

corn oil

Concentration / amount:

100% (control group)

Day(s)/duration:

Day 1

Route:

intradermal

Vehicle:

corn oil

Concentration / amount:

5% w/v in corn oil (test group)

Day(s)/duration:

Day 1

Adequacy of induction:

other: highest concentration used causing no more than mild-to-moderate skin irritation and well tolerated systemically

Route:

epicutaneous, occlusive

Vehicle:

corn oil

Concentration / amount:

100% (control group)

Day(s)/duration:

Day 8 / 48 hours

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

100% (undiluted) (test group)

Day(s)/duration:

Day 8 / 48 hours

Adequacy of induction:

other: highest concentration used causing no more than mild-to-moderate skin irritation and well tolerated systemically

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

100% (undiluted) (control group)

Day(s)/duration:

Day 22 / 24 hours

Adequacy of challenge:

highest non-irritant concentration

No.:

#2

Route:

epicutaneous, occlusive

Vehicle:

corn oil

Concentration / amount:

50% (control group)

Day(s)/duration:

Day 22 / 24 hours

Adequacy of challenge:

highest non-irritant concentration

No.:

#3

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

100% (undiluted) (test group)

Day(s)/duration:

Day 22 / 24 hours

Adequacy of challenge:

highest non-irritant concentration

No.:

#4

Route:

epicutaneous, occlusive

Vehicle:

corn oil

Concentration / amount:

50% (test group)

Day(s)/duration:

Day 22 / 24 hours

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

Preliminary test: 8 male animals

Main test:
Intra-dermal induction exposure:
- control group: 5
- test group: 10
Dermal induction exposure:
- control group: 5
- test group: 10
Challenge exposure:
- control group: 5
- test group: 10

Details on study design:

RANGE FINDING TESTS:
Test item concentrations:
- intra-dermal injection: 0.5, 1, 2.5 and 5% (w/v)
- dermal application: 25, 50, 75 and 100% (w/v)
Time of observations for local effects:
- Preliminary study: daily, up to 6 days.
- Intra-dermal induction exposure: 24 hours after treatment.
- Dermal induction exposure: 1, 24, 48 and 72 hours after patch removal.
- Challenge exposure: 24 and 48 hours after patch removal.
Exposure time:
- For the dermal treatment: 48 hours.
Test item application and observations:
- For the intra-dermal application, 0.1 mL per concentration was injected intra-dermally into the hair free skin of the flanks. One concentration was injected on the right side and another concentration on the left side of the animals. Each concentration was injected in duplicate. Two animals were used per concentration.
- For the dermal application, approximately 0.5 mL per concentration was applied onto the clipped and shaved skin of the animals. A closed patch exposure was performed by means of an occlusive bandage using similar treatment procedures as for the main study. One concentration was used on the right side and another concentration on the left side of the animals. Two animals were used per concentration. Time of exposure was 48 hours.

MAIN STUDY
A. Intradermal induction exposure
- Control group: 5 animals
- Test group: 10 animals
Concentration of the test item:
- Control: corn oil
- Test group: 5% (w/v) in corn oil
Day of treatment: 1
Site of treatment: shoulder
Time of observations: 24 hours after the treatment

B. Dermal induction exposure
- Control group: 5 animals
- Test group: 10 animals
Concentration of the test item:
- Control: corn oil
- Test group: 100% (undiluted)
Day of treatment: 8
Site of treatment: shoulder
Duration of exposure: 48 hours
Time of observations: 1, 24, 48 and 72 hours after the patch removal

C. Challenge exposure
- Control group: 5 animals
- Test group: 10 animals
Concentration of the test item:
- Control: 100% (undiluted) and 50% (w/v) in corn oil
- Test group: 100% (undiluted) and 50% (w/v) in corn oil
Day of treatment: 22
Site of treatment: flank
Duration of exposure: 24 hours
Time of observations: 24 and 48 hours after the patch removal

Challenge controls:

As described in details on study design

Positive control substance(s):

yes

Remarks:

2-mercaptobenzothiazole

Positive control results:

Challenge with reference item 2-mercaptobenzothiazole resulted in a positive response in test animals previously sensitised. The net response values at the 24 and 48 hour observations represented an incidence rate of 100% and 90% and net score values of 1.00 and 0.90 respectively. In the control animals no visible changes were found either at the 24 or 48 hour examinations following challenge with the reference item.
The dermal scores represented discrete erythema (score 1) developed on the skin of sensitised guinea pigs.
On the basis of the results of the reliability check study, the reference item 2-mercaptobenzothiazole was classified as a skin sensitizer. This demonstrated that the experimental procedure and the test system were appropriate.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

100% (undiluted)

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no reactions were found

Remarks on result:

other: Reading: 1st reading. Hours after challenge: 24.0. Group: test group. Dose level: 100% (undiluted). No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no reactions were found.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

100% (undiluted)

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no reactions were found

Remarks on result:

other: Reading: 2nd reading. Hours after challenge: 48.0. Group: test group. 100% (undiluted). No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no reactions were found.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

100% (undiluted)

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

no reactions were found

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 100% (undiluted). No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: no reactions were found.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

100% (undiluted)

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

no reactions were found

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 100% (undiluted). No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: no reactions were found.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

50% (w/v) in corn oil

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no reactions were found

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

50 % (w/v) in corn oil

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no reactions were found

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

50% (w/v) in corn oil

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

no reactions were found

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

50% (w/v) in corn oil

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

no reactions were found

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

50%

No. with + reactions:

10

Total no. in group:

10

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

50%

No. with + reactions:

9

Total no. in group:

10

Interpretation of results:

GHS criteria not met

Conclusions:

In conclusion, under the conditions of the present assay the test item Rhodiantal original IBCH was shown to have no sensitisation potential and therefore it is classified as a non-sensitizer, according to current EU-regulations.

Executive summary:

A skin sensitisation study was performed in the guinea pig according to the Magnusson-Kligman method, using a maximisation method with Freund's Complete Adjuvant to evaluate the sensitisation potential of test item RHODIANTAL ORIGINAL IBCH. The study was performed according to OECD Guideline No. 406 (adopted in 1992) and in compliance with GLP guidelines.

Based on the results of a preliminary test, ten naive test animals were subjected to sensitisation procedures in a two-stage process, named induction phase: i.e. an intra-dermal treatment and a 48h topical application (dermal treatment under an occlusive dressing). The test item was used at a concentration of 5% (w/v) for intra-dermal injections and at a concentration of 100% (undiluted) for topical sensitisation treatment. Five naive control guinea pigs were simultaneously exposed to corn oil during the sensitisation phase.

Two weeks after the last induction exposure, a challenge dose (at a concentration of 100% (undiluted)) was administered on the left flank of all animals. The right flank area of the animals was treated with 50% dilution of the maximum dermal challenge dose as a safeguard dose (50% (w/v) in corn oil). Challenge was performed by dermal application of the test item. Skin reactions were measured 24 and 48 h after patch removal.

Incidence Rate:

No signs of systemic toxicity were observed in any animal.

During the induction period very slight erythema (score 1) was observed in test animals 1 and 24 hours after the dermal treatment (on Days 10 and 11). No further local skin effects were observed in either the test group or in the control group.

Intensity of Sensitisation Response:

Following challenge with the concentrations of 100% (undiluted) and 50% (w/v) RHODIANTAL ORIGINAL IBCH in corn oil, there were no skin reactions in the test or control animals.

The net response value represented an incidence rate of 0% after a challenge exposure at both 100% (undiluted) and 50% (w/v) RHODIANTAL ORIGINAL IBCH in corn oil.

In conclusion, under the conditions of the present assay the test item RHODIANTAL ORIGINAL IBCH (Batch No.: ZRP15010GD) was shown to have no sensitisation potential and classified as a non-sensitizer, according to current EU-regulations.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Two in vivo studies (LLNA and Magnusson and Kligman tests) (Klimish score 1) were conducted to assess the skin sensitisation potential of the registered substance.

First an in vivo test (LLNA) was performed in 2009 which gave ambiguous results due to irritating effects. The local lymph node assay (LLNA) was performed according to the OECD Guideline 429 and under GLP regulations. Neither mortality nor clinical signs were observed during the study. On day 6, a dryness of the skin was observed in all animals treated at the concentrations of 10 and 25%. An erythema was also noted on day 6 in all animals treated at the concentration of 25%, associated with crusts in one female. No significant increase in ear thickness was observed in the animals of the treated groups. A significant lymphoproliferation was noted in the positive control group given HCA. The study was therefore considered valid. A significant lymphoproliferation (SI > 3) was noted at the concentration of 25%. In the absence of excessive increase in ear thickness, the significant lymphoproliferative response observed should be attributed to delayed contact hypersensitivity. However, observed erythemas and crusts on the ears of the animals of the 25% concentration test item treated group may be a sign of skin lesions that could have interfere with the results of the present study. Therefore, the sensitizing potential of the test item at concentrations higher than 10% remains questionable. For this reasons, the EC3 value for the test item Rhodiantal IBCH (equal to 11%) should be considered as irrelevant. Under the experimental conditions of this study, the test item Rhodiantal IBCH induced no delayed contact hypersensitivity in the murine Local Lymph Node Assay at the maximum concentration of 10%. At concentrations higher than 10% the potential of the test item Rhodiantal IBCH to induce delayed contact hypersensitivity in the murine Local Lymph Node Assay remains questionable. Therefore based on the results of this study it was not possible to conclude on the sensitizer potential of the substance and no classification can be proposed.

In order to discriminate the sensitization potential from the irritating response, an other in vivo test in the guinea pig (Magnusson and Kligman assay) was performed according to the OECD Guideline 406 and under GLP regulations. Based on the results of a preliminary test, ten naive test animals were subjected to sensitisation procedures in a two-stage process, named induction phase: i.e. an intra-dermal treatment and a 48h topical application (dermal treatment under an occlusive dressing). The test item was used at a concentration of 5% (w/v) for intra-dermal injections and at a concentration of 100% (undiluted) for topical sensitisation treatment. Five naive control guinea pigs were simultaneously exposed to corn oil during the sensitisation phase. Two weeks after the last induction exposure, a challenge dose (at a concentration of 100% (undiluted)) was administered on the left flank of all animals. The right flank area of the animals was treated with 50% dilution of the maximum dermal challenge dose as a safeguard dose (50% (w/v) in corn oil). Challenge was performed by dermal application of the test item. Skin reactions were measured 24 and 48 h after patch removal. No signs of systemic toxicity were observed in any animal. During the induction period very slight erythema (score 1) was observed in test animals 1 and 24 hours after the dermal treatment (on Days 10 and 11). No further local skin effects were observed in either the test group or in the control group. Following challenge with the concentrations of 100% (undiluted) and 50% (w/v) RHODIANTAL ORIGINAL IBCH in corn oil, there were no skin reactions in the test or control animals.

The net response value represented an incidence rate of 0% after a challenge exposure at both 100% (undiluted) and 50% (w/v) RHODIANTAL ORIGINAL IBCH in corn oil. Under the conditions of the present assay, the test item was shown to have no sensitisation potential.

The Magnusson and Kligman assay in guinea pigs shows that the registered substance does not present any skin sensitizing potential. Based on this study the registered substance is not considered to be a skin sensitizer and no classification is required. The ambiguous results obtained in the LLNA study are considered to be secondary to the irritation. Since the substance is viscous the mice have scratching their ears.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Harmonized classification:

No harmonized classification is available according to the Regulation (EC) No 1272/2008.

 

Self classification:

Phenol, 2-methoxy-, reaction products with 2,2- dimethyl-3-methylenebicyclo[2.2.1]heptane, hydrogenated is not classified as a skin sensitiser according to the Regulation (EC) 1272/2008 (CLP) and to the Directive 67/548/EEC.