SUMILIZER GP

Endpoint summary

Description of key information

Skin sensitisation (OECD 406, GPMT): not sensitising

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09 Oct - 08 Dec 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

adopted in 1996

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

adopted in 2008

Deviations:

yes

Remarks:

environmental condition for animals: the temperature was outside the recommended range (24 ± 2 °C instead of 20 ± 3 °C)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

adopted in1992

Deviations:

yes

Remarks:

environmental condition for animals: the temperature was outside the recommended range (24 ± 2 °C instead of 20 ± 3 °C)

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

A non-LLNA test is available that was performed prior to the current data requirements, stipulated in Regulation (EC) No 1907/2006. In accordance with the same Regulation, the data was included to avoid unnecessary testing.

Species:

guinea pig

Strain:

Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River Japan, Co., Ltd. (Kanagawa, Japan)
- Females nulliparous and non-pregnant: yes
- Age at study initiation: approx. 4 weeks
- Weight at study initiation: 351 - 460 g
- Housing: 5/sex in aluminium cages (W450 x D550 x H350 mm)
- Diet: GC-4 (Oriental Yeast Co., Ltd., Tokyo, Japan), ad libitum)
- Water: filtered tap water, ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 ± 2
- Humidity (%): 50 ± 20
- Air changes (per hr): > 10
- Photoperiod (hrs dark / hrs light): 12/12

Route:

intradermal and epicutaneous

Vehicle:

other: intradermal induction: corn oil; epicutaneous induction: acetone

Concentration / amount:

intradermal induction on Day 0: 5%
epicutaneous induction on Day 7: 50%

Day(s)/duration:

intradermal induction: single treatment; epicutaneous induction: 48 h

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

No.:

#1

Route:

epicutaneous, semiocclusive

Vehicle:

other: acetone

Concentration / amount:

5%

Day(s)/duration:

24 h

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

10 (controls), 20 (in test groups)

Details on study design:

RANGE FINDING TESTS:
A dose-finding study was conducted in order to select suitable concentrations for sensitisation and challenge.
For intradermal injection, concentrations in the range of 0.1 - 5% of the test substance in corn oil were applied. 6 test item concentrations and vehicle control were injected at a volume of 0.1 mL into 3 guinea pigs (7 doses/body). For epicutaneous exposure, concentrations in the range of 5 - 50% of the test substance in acetone were applied for 24 h. 4 test item concentrations were applied to the skin of 6 guinea pigs (2 doses/body). Skin reactions were evaluated 24 and 48 h post application. Concentrations for the main experiment were chosen to cause mild irritation after intradermal and epicutaneous induction. Concentrations for the main experiment challenge were chosen to represent the highest non-irritating concentration.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2 (intradermal and epicutaneous, respectively)
- Exposure period: single injection (intradermal) and 48 h (epicutaneous)
- Test groups:
Intradermal (3 pairs of injections):
Injection 1: 1:1 (v/v) mixture complete Freund's adjuvant (FCA) and water (water in oil emulsion)
Injection 2: 5% test substance in corn oil
Injection 3: 5% test substance in a 1:1 mixture of complete Freund's adjuvant (FCA) and distilled water
Epicutaneous: 0.4 mL test substance 50%
- Control group:
Intradermal (3 pairs of injections):
Injection 1: 1:1 (v/v) mixture complete Freund's adjuvant (FCA) and water (water in oil emulsion)
Injection 2: corn oil
Injection 3: 5% corn oil in a 1:1 mixture of complete Freund's adjuvant (FCA) and distilled water
Epicutaneous: 0.4 mL acetone
- Site: dorsal skin in the scapular region
- Frequency of applications: topical induction was performed 1 week after the intradermal induction
- Duration: Days 0 - 7
- Concentrations: intradermal 5%, epicutaneous 50%

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Days of challenge: 3 weeks after intradermal induction
- Exposure period: 24 h
- Test groups: test substance and vehicle
- Control group: test substance and vehicle
- Site: left flank (test item) and right flank (vehicle)
- Concentrations: 5%
- Evaluation (hr after challenge): 24 and 48 h after patch removal

OTHER:
All animals were observed for clinical signs of toxicity and body weight development during the course of the study.

Challenge controls:

The control group is actually a challenge control

Positive control substance(s):

yes

Remarks:

a-hexylcinnamaldehyde (HCA)

Positive control results:

The positive control substance (a-hexylcinnamaldehyde in acetone, 5% for intradermal induction, 100% for epicutaneous induction and 10% for epicutaneous treatment at challenge) induced positive reactions in 4/5 animals (80%), thus meeting the reliability criteria for the GPMT test (≥ 30% positive response).

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

challenge 5% epicutaneous

No. with + reactions:

0

Total no. in group:

10

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

induction: 5% intradermal, 50% epicutaneous; challenge 5% epicutaneous

No. with + reactions:

0

Total no. in group:

20

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

induction: 5% intradermal, 100% epicutaneous; challenge 10% epicutaneous

No. with + reactions:

4

Total no. in group:

5

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

challenge 5% epicutaneous

No. with + reactions:

0

Total no. in group:

10

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

induction: 5% intradermal, 50% epicutaneous; challenge 5% epicutaneous

No. with + reactions:

0

Total no. in group:

20

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

induction: 5% intradermal, 100% epicutaneous; challenge 10%

No. with + reactions:

4

Total no. in group:

5

No clinical signs of systemic toxicity were observed for any animal. In addition, the body weights of all animals increased similarly during the study period.

Interpretation of results:

other: CLP/EU GHS criteria not met, no classification required according to Regulation (EC) No. 1272/2008.

Conclusions:

CLP: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

A GPMT assay analysing the skin sensitising properties of Sumilizer GP was conducted according to OECD guideline 406 and compliant with GLP. Test item concentrations for the study were selected based on the results of a preliminary toxicity study, and chosen to cause mild irritation after intradermal and epicutaneous induction. 

In the main study, twenty female Hartley guinea pigs were induced intradermally with 5% test substance formulated in corn oil on study Day 0, followed by epicutaneous induction with 50% test substance formulated in acetone on study Day 7. After 48 h of exposure under semi-occlusive conditions, the patch was removed. Three weeks after the induction, the animals were challenged by epicutaneous treatment with 5% test item formulated in acetone. A similar constituted group of 10 vehicle control animals was induced, but remained untreated during the challenge. Further, a group of 5 positive control animals was induced intradermally with 5% and epicutaneously with 100% alpha-hexylcinnamaldehyde and challenged with 10% alpha-hexylcinnamaldehyde. Following 24 h of challenge exposure under semi-occlusive conditions, the patches were removed. Skin reactions were evaluated 24 and 48 h after removal of the test substance.

No clinical signs of systemic toxicity were observed for any animal. In addition, the body weights of all animals increased similarly during the study period. There were no skin reactions recorded at any reading time point in any test item-treated animal. Solvent and positive control treated animals showed the expected results, thus demonstrating the sensitivity and validity of the test system.

Based on the results of the study, the test item is not considered to be a skin sensitiser.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The available data on skin sensitisation do not meet the criteria for classification according to Regulation (EC) No. 1272/2008 (CLP) and are therefore conclusive but not sufficient for classification.