2-Ethylhexyl trans-4-methoxycinnamate

Endpoint summary

Description of key information

Guinea Pig Maximisation Test (GPMT) (75 % ethylhexyl methoxycinnamate in olive oil): not sensitising (OECD 406, GLP)

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

according to guideline, GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

According to Column 2 of Annex VII (point 8.3.2), in vivo skin sensitisation studies that were carried out or initiated before 11 October 2016, and that meet the requirements set out in Article 13(3), first subparagraph, and Article 13(4) shall be considered appropriate to address this standard information requirement.

Species:

guinea pig

Strain:

Pirbright-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Lippische Versuchstierzucht, Hagemann GmbH & Co. KG, D-W4923 Extertal 1, FRG
- Age at study initiation: Young adult animals
- Weight at study initiation: 270 - 335 g
- Housing: Makrolon, type IV cages, 5 animals per cage, Bedding: Granulat Typ 3/4 (staubfrei); SSNIFF
- Diet (e.g. ad libitum): Kliba Labordiät 341 (Kaninchen-Meerschweinchen-Haltungsdiät) ad libitum
- Water (e.g. ad libitum): Water ad libitum (tap water; about 2 g of ascorbic acid per 10 l water was added to the drinking water twice a week)
- Acclimation period: 7 days before the beginning of the study in the laboratory

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): 30 - 70
- Photoperiod (hrs dark / hrs light): 12 h light (6.00 - 18.00 hours) / 12 h darkness (18.00 - 6.00 hours)

Route:

intradermal and epicutaneous

Vehicle:

other: Freund's adjuvant, olive oil DAB 9

Concentration / amount:

Pretest: 5 % (intradermal), 75 %/ 100 % (epicutaneous)
Main test:
Induction: 5 % (intradermal), 75 %/ 100 % (epicutaneous)
Challenge: 75 %

Route:

epicutaneous, occlusive

Vehicle:

other: Freund's adjuvant, olive oil DAB 9

Concentration / amount:

Pretest: 5 % (intradermal), 75 %/ 100 % (epicutaneous)
Main test:
Induction: 5 % (intradermal), 75 %/ 100 % (epicutaneous)
Challenge: 75 %

No. of animals per dose:

Pretest: 4
control group: 10
Test group: 20

Details on study design:

RANGE FINDING TESTS:
Exposure period: 2 times for 24 hours within a period of 96 hours,
Exposure: 2 x 2 cm filter paper strips (soaked in the test substance = about 0.15 g) , occlusive (rubberized linenpatches 4 x 4 cm from Russka and Fixomull® Stretch (adhesive fleece) from Beiersdorf AG)
Site of application: flank, respective on the same area
Readings: about 24 and 48 h after the beginning of application

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2 (intradermal, epicutaneous)
- Exposure period: 48 hours (epicutaneous), occlusive
- Site: shoulder, same area for intradermal / epicutaneous application
- Frequency of applications: Percutaneous induction was carried out one week after intradermal induction
- Concentrations:
Intradermal:
A) 0.1 mL Freund's adjuvant, emulsified with 0.9 % aqueous NaCl-solution (1 : 1)
B) 0.1 mL test substance (5 % in olive oil DAB 9 )
C) 0.1 mL Freund's adjuvant in 0.9% aqueous NaC1-solution (1 : 1) containing test substance (5 % in olive oil DAB 9)
Epicutaneous: approx. 0.3 g undiluted test substance
- Control group: Intradermal: test substance injections (A, B, C) but without test substance; epicutaneous: no treatment
B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 21 days after intradermal induction
- Exposure period: 48 hours epicutaneous, occlusive
- Control group: treated as test group
- Site: intact flank
- Concentrations: test substance 75 % in olive oil DAB 9
- Evaluation (hr after challenge): 24 and 48 h after the removal of the patch

Challenge controls:

Induction: Intradermal: test substance injections (A, B, C) but without test substance; epicutaneous: no treatment
Challenge: treated as test group

Positive control substance(s):

yes

Remarks:

1-chlor-2,4-dinitro-benzol

Positive control results:

Challenge with 1 % of 1-chlor-2,4-dinitro-benzol in ethanol led to visual skin findings in 20 of 20 animals
Moderate to severe erythema and very slight edema in 2 of 20 test group animals.
Well-defined erythema in 14 of 20 test group animals; in 11 additionally very slight edema.
Very slight erythema in 4 of 20 test group animals.
No skin reactions in control group animals.
The vehicle did not cause any skin reactions in all animals.

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

1 % of 1-chlor-2,4-dinitro-benzol in ethanol

No. with + reactions:

20

Total no. in group:

20

Clinical observations:

Visual skin findings in 20 of 20 animals: Moderate to severe erythema and very slight edema

Remarks on result:

positive indication of skin sensitisation

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

1 % of 1-chlor-2,4-dinitro-benzol in ethanol

No. with + reactions:

20

Total no. in group:

20

Clinical observations:

Visual skin findings in 20 of 20 animals: Moderate to severe erythema and very slight edema

Remarks on result:

positive indication of skin sensitisation

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

Olive oil DAB9/ test substance solely at challenge

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No clinical signs were observed

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

Olive oil DAB9/ test substance solely at challenge

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No clinical signs were observed

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

75 % in olive oil DAB9

No. with + reactions:

1

Total no. in group:

20

Clinical observations:

Well-defined signs of irritation (grade 2 erythema) in one test group animal

Remarks on result:

no indication of skin sensitisation

Remarks:

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

75 % in olive oil DAB9

No. with + reactions:

1

Total no. in group:

20

Clinical observations:

Well-defined signs of irritation (grade 2 erythema) in one test group animal

Remarks on result:

no indication of skin sensitisation

Intradermal induction caused slight to well-defined signs of irritation in the test group animals. Percutaneous induction caused in animals of the test group incrustation, partially open (caused by the intradermal induction) in addition to slight to well-defined signs of irritation. Challenge: Well-defined signs of irritation (grade 2 erythema) in one test group animal. No skin reaction was seen at skin sites of the test animals treated with vehicle or treated with test substance solely at challenge.

 

According to the authors, a second challenge application was not necessary on the basis of the inequivocal results of the first challenge.

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the results of the study under the test conditions chosen, it was concluded that Uvinul MC 80 does not have a sensitizing effect on the skin of the guinea pig in the Maximization Test.

Reference 2

Endpoint:

skin sensitisation: in vitro

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

an in vitro skin sensitisation study does not need to be conducted because adequate data from an in vivo skin sensitisation study are available

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The GPMT study was performed according to OECD guideline 406 and GLP (BASF SE, 1993). The results show that the 75% solution of ethylhexyl methoxycinnamate in olive oil only induces a minor skin reaction in the guinea pig. It can therefore be concluded that the substance ethylhexyl methoxycinnamate does not have sensitising properties to the skin according to the criteria outlined in the regulation 1272/2008/EC (CLP/EU-GHS).

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

Not relevant, as inhalation of ethylhexyl methoxycinnamate is not expected.

Justification for classification or non-classification

Both the key and supporting sensitisation studies indicate that ethylhexyl methoxycinnamate does not provoke significant positive immunogenic reactions. The sensitisation rate in the key study does not exceed the critical value of 30 %. Therefore, it can be concluded that the substance is not sensitising and therefore does not need to be classified as such according to the criteria outlined in 1272/2008/EC (CLP/EU-GHS).