Resinoid of Liquidambar styraciflua (Hamamelidaceae) obtained from exudate by organic solvents extraction

Endpoint summary

Description of key information

In vivo: Skin sensitiser Cat. 1 (WoE - Constituent approach, Guinea pig study, non OECD, non GLP, rel.4)

QSAR: Skin sensitiser Cat. 1 (WoE - Constituent approach, QSAR models, rel.2)

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation, other

Remarks:

QSAR approach

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Study period:

27 March 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Remarks:

No QPRF report was provided as model output. Those predictions have been considered sufficient, together with in vivo data on the main constituant (non-LLNA), to classify the registered substance without further testing using a weight of evidence approach.

Justification for type of information:

1. SOFTWARE
- VEGA v1.1.4
- Danish QSAR Database
- OECD QSAR Toolbox v4.1
- Toxtree v2.6.13

2. MODEL (incl. version number)
- Skin Sensitisation model (CAESAR) (version 2.1.6) of VEGA 1.1.4
- SciQSAR, LeadScope and CASE Ultra of Danish QSAR Database
- Structural alerts for protein binding of OECD QSAR Toolbox v4.1:
Protein binding by OASIS
Protein binding by OECD
Protein binding potency Cys (DPRA 13%)
Protein binding potency Lys (DPRA 13%)
Keratinocyte gene expression
Protein binding alerts for skin sensitisation according to the GHS
Protein binding alerts for skin sensitisation by OASIS
Protein binding potency h-CLAT
- Decision trees of Toxtree v2.6.13:
Skin sensitisation reactivity domains
Protein binding alerts

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
SMILES code / CAS Number : C(=O)(C=Cc1ccccc1)OCC=Cc1ccccc1 / 122-69-0

Qualifier:

no guideline followed

Principles of method if other than guideline:

The Skin Sensitisation potential of the main constituent of the registered substance was determined using available structural alert systems and Quantitative Structure-Activity Relationship (QSAR) models.

GLP compliance:

no

Justification for non-LLNA method:

Those predictions have been considered sufficient, together with in vivo data on the main constituant (non-LLNA), to classify the registered substance without further testing using a weight of evidence approach.

Key result

Parameter:

other: Classification

Remarks on result:

positive indication of skin sensitisation

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

Cinnamyl cinnamate, the main constituent of the registered substance, was associated with protein binding alerts with Toxtree and Toolbox and classified as a skin sensitiser by the VEGA QSAR model and Danish QSAR Database. The registered substance has not been tested itself in appropriate in vitro or in vivo tests but its main constituent Cinnamyl cinnamate is present above the CLP generic concentration limit of 1% that triggers classification of the mixture. Therefore, the registered substance is classified as a skin sensitiser Cat. 1 according to the Regulation (EC) No 1272/2008.

Executive summary:

Regarding the profile of Cinnamyl cinnamate, the main constituent of the registered substance, we conclude that at least this constituant is classified as Skin Sensitiser 1.

No QSAR evaluations were therefore performed on the remaining constituents.

The registered substance is a UVCB composed of several constituents and in that, it can be considered as a mixture according to the definition of the CLP Regulation. The decision logic for classification of mixtures from the ECHA Guidance on the Application of the CLP Criteria (2017) was used to determine the skin sensitising potential of the registered substance.

Cinnamyl cinnamate, the main constituent of the registered substance, was associated with protein binding alerts with Toxtree and Toolbox and classified as a skin sensitiser by the VEGA QSAR model and Danish QSAR Database. The registered substance has not been tested itself in appropriate in vitro or in vivo tests but its main constituent Cinnamyl cinnamate is present above the CLP generic concentration limit of 1% that triggers classification of the mixture. Therefore, the registered substance is classified as a skin sensitiser Cat. 1 according to the Regulation (EC) No 1272/2008.

Those predictions have been considered sufficient, together with in vivo data on the main constituant, to classify the registered substance without further testing using a weight of evidence approach.

Reference 2

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1995

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Remarks:

Those in vivo data have been considered sufficient, together with QSARs predictions on the main constituant, to classify the registered substance without further testing using a weight of evidence approach.

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: Sensitization was performed with Cinnamyl Cinamate according to a modified Freund's complete adjuvant technique (Guinea pigs modified FCA method). The method was developed from Freund's complete adjuvant test (FCAT) and the guinea pig maximisation test (GPMT) in order to determine the sensitizing capacity of medium and weak allergens.
- Short description of test conditions:
Induction by 6 intradermal injections on day 1, day 5 and day 9 of Cinnamyl cinnamate dissolved in FCA and physiologicals aline.
Topical challenge on day 20 by open application. The challenge doses were 3 and 10% Cinnayl cinnamate in acetone.
Reading at 24, 48 and 72 hours.
The mean response was computed as the quotient of the sum of all reactions obtained divided by the total number of treated animals. A mean response of 0 to 1 was considered as weak, 1 to 2 as moderate, and greater than 2 as strong.
- Parameters analysed / observed: Skin irritation. Scoring of the response 0 to 1 was considered as weak, 1 to 2 as moderate, and greater than 2 as strong

GLP compliance:

not specified

Type of study:

other: modified Freund's complete adjuvant method

Justification for non-LLNA method:

At the time of study completion (1995), the LLNA OECD test method was not adopted.

Species:

guinea pig

Strain:

other: Pirbright white strain

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: not reported
- Females (if applicable) nulliparous and non-pregnant: not specified
- Age at study initiation: ot reported
- Weight at study initiation: 280 to 350 g
- Housing: 3 to a cage
- Diet (e.g. ad libitum): yes, pellets
- Water (e.g. ad libitum): yes
- Acclimation period: not reported

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 to 24 °C
- Humidity (%): 50 to 55 %
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 10 hours light
- IN-LIFE DATES: not reported

Route:

intradermal

Vehicle:

other: Freund's complete adjuvant (FCA) + physiological saline (1:1)

Concentration / amount:

15 mg of Cinnamyl cinnamate in 8 mL of solvent

Day(s)/duration:

6 intradermal injections on day 1, 5 and 9.

Adequacy of induction:

not specified

No.:

#1

Route:

epicutaneous, open

Vehicle:

other: acetone

Concentration / amount:

3%

Day(s)/duration:

Eleven days after induction

Adequacy of challenge:

highest non-irritant concentration

No.:

#2

Route:

epicutaneous, open

Vehicle:

other: acetone

Concentration / amount:

10%

Day(s)/duration:

Eleven days after induction

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

10

Details on study design:

RANGE FINDING TESTS: determination of irritancy
Ten guinea pigs were treated with the emulsion of FCA and physiological saline but without the tested material. They served also to determine patterns of irritation. One day before challenge, these animals were tested by applying different molar concentrations of test material to the right flank (0.1, 0.3 and 1.0 mol). The results were read after 24 hours.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: Induction by 6 intradermal injections on day 1, day 5 and day 9 of Cinnamyl cinnamate dissolved in FCA and physiologicals aline.
- Test groups: yes
- Control group: see range finding test
- Concentrations: 15 mg of Cinnamyl cinnamate in 8 mL of solvent

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: Day 20 (eleven days following induction)
- Exposure period: open application
- Site: clipped and shave flank of the animals
- Concentrations: 3 and 10% in acetone
- Evaluation (hr after challenge): 24, 48 and 72 hours

OTHER:
The mean response was computed as the quotient of the sum of all reactions obtained divided by the total number of treated animals. A mean response of 0 to 1 was considered as weak, 1 to 2 as moderate, and greater than 2 as strong.

Challenge controls:

Not reported

Positive control substance(s):

not specified

Positive control results:

Not applicable

Key result

Reading:

1st reading

Group:

test chemical

Dose level:

3% in acetone

Total no. in group:

10

Clinical observations:

not reported

Remarks on result:

positive indication of skin sensitisation

Remarks:

detailed results not reported

Key result

Reading:

1st reading

Group:

test chemical

Dose level:

10 % in acetone

Total no. in group:

10

Clinical observations:

not reported

Remarks on result:

positive indication of skin sensitisation

Remarks:

detailed results

Reading:

1st reading

Group:

negative control

Dose level:

Acetone

No. with + reactions:

0

Total no. in group:

0

Clinical observations:

not reported

Remarks on result:

not measured/tested

Remarks:

No negative control reported in the available public data

Reading:

1st reading

Group:

positive control

Dose level:

Not reported

No. with + reactions:

0

Total no. in group:

0

Clinical observations:

not reported

Remarks on result:

not measured/tested

Remarks:

No positive control reported in the available public data

Mean response at 3 % (24, 48 and 72h after challenge) = 0.10

Mean response at 10 % (24, 48 and 72h after challenge) = 0.47

Cinnamyl cinnamate was concluded as weak sensitiser

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

Under the test conditions, Cinnamyl cinnamate, the main constituent of the registered substance, is classified as sensitiser category 1 according to Regulation (EC) No. 1272/2008 (CLP) and to the GHS. The registered substance has not been tested itself in appropriate in vitro or in vivo tests but its main constituent Cinnamyl cinnamate is present above the CLP generic concentration limit of 1% that triggers classification of the mixture. Therefore, the registered substance is classified as a skin sensitiser Cat. 1 without further testing according to the Regulation (EC) No 1272/2008.

Executive summary:

Sensitization was performed with Cinnamyl Cinamate according to a modified Freund's complete adjuvant (FCA) test method. The method was developed from Freund's complete adjuvant test (FCAT) and the guinea pig maximisation test (GPMT) in order to determine the sensitizing capacity of medium and weak allergens.

Ten female albino Guinea pigs of the Pirbright white strain were treated as follows: Induction by 6 intradermal injections on day 1, day 5 and day 9 with Cinnamyl cinnamate dissolved in FCA and physiologicals aline (1:1) (15 mg in 8 mL). Topical challenge on day 20 by open application. The challenge doses were 3 and 10% Cinnamyl cinnamate in acetone. Reading was done at 24, 48 and 72 hours.

The mean response was computed as the quotient of the sum of all reactions obtained divided by the total number of treated animals. A mean response of 0 to 1 was considered as weak, 1 to 2 as moderate, and greater than 2 as strong.

Cutaneous reactions were observed and considered to be sensitisation reactions. Mean responses of 0.1 at 3% and 0.47 at 10% indicate that Cinnamyl cinnamate is a weak sensitiser.

Mortality, body weight gain and clinical signs were not reported.

Under the test conditions, Cinnamyl cinnamate is considered as sensitiser.

The registered substance is a UVCB composed of several constituents and in that, it can be considered as a mixture according to the definition of the CLP Regulation. The decision logic for classification of mixtures from the ECHA Guidance on the Application of the CLP Criteria (2017) was used to determine the skin sensitising potential of the registered substance.

Cinnamyl cinnamate, the main constituent of the registered substance, was considered as a skin sensitiser in a in vivo study. The registered substance has not been tested itself in appropriate in vitro or in vivo tests but its main constituent Cinnamyl cinnamate is present above the CLP generic concentration limit of 1% that triggers classification of the mixture. Therefore, the registered substance is classified as a skin sensitiser Cat. 1 according to the Regulation (EC) No 1272/2008.

Those in vivo data have been considered sufficient, together with QSARs predictions on the main constituant, to classify the registered substance without further testing using a weight of evidence approach.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

The registered substance is a UVCB composed of several constituents and in that, it can be considered as a mixture according to the definition of the CLP Regulation. The decision logic for classification of mixtures from the ECHA Guidance on the Application of the CLP Criteria (2017) was used to determine the skin sensitising potential of the registered substance.

Cinnamyl cinnamate, the main constituent of the registered substance, was tested in an in vivo study using modified Freund's complete adjuvant (FCA) test method (Hausen, 1995, rel. 4).

Ten Guinea pigs were treated as follows: Induction by 6 intradermal injections on day 1, day 5 and day 9 with Cinnamyl cinnamate dissolved in FCA and physiological saline (1:1) (15 mg in 8 mL). Topical challenge on day 20 by open application. The challenge doses were 3 and 10% Cinnamyl cinnamate in acetone. Reading was done at 24, 48 and 72 hours.

The mean response was computed as the quotient of the sum of all reactions obtained divided by the total number of treated animals. A mean response of 0 to 1 was considered as weak, 1 to 2 as moderate, and greater than 2 as strong. Cutaneous reactions were observed and considered to be sensitisation reactions. Mean responses of 0.1 at 3% and 0.47 at 10% indicate that Cinnamyl cinnamate is a weak sensitiser. Mortality, body weight gain and clinical signs were not reported. Under the test conditions, Cinnamyl cinnamate is considered as sensitiser.

This study was reported as a scientific publication. In view of low level of details available, it was considered more appropriate to conclude using a weight of evidence with prediction tools. Indeed Cinnamyl cinnamate was associated with protein binding alerts with Toxtree and Toolbox and classified as a skin sensitiser by the VEGA QSAR model and Danish QSAR Database.

The registered substance has not been tested itself in appropriate in vitro or in vivo tests but its main constituent Cinnamyl cinnamate is present above the CLP generic concentration limit of 1% that triggers classification of the mixture. Therefore, considering all the data available on its main constituent, the registered substance is classified as a skin sensitiser Cat. 1 according to the Regulation (EC) No 1272/2008.

This weight of evidence was considered sufficient to classify the registered substance without further testing.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

Under the REACH regulation there is no legal standard information requirement in Annexes VII to X to perform any specific test for respiratory sensitisation. In addition, no validated or widely recognised in vitro or in vivo test methods specific to respiratory sensitisation are available yet. No human or animal data are available on the source or on the target substances to address respiratory sensitisation. No alert for respiratory sensitisation were found by the OECD QSAR Toolbox.

Justification for classification or non-classification

Harmonised classification:

The substance has no harmonised classification according to the Regulation (EC) No. 1272/2008 (CLP).

Self-classification:

Based on the available data, the substance is classified as Skin Sens. 1 (H317: May cause an allergic skin reaction) according to the Regulation (EC) No. 1272/2008 (CLP) and to the GHS.

No direct scientific data are available on the substance to address respiratory sensitisation.