2-methoxy-4-propylphenol

Endpoint summary

Description of key information

Skin irritation/corrosion: irritating based on the absence of skin corrosion in vitro (TER, OECD 430, GLP, rel. 1, K) and based on available data which indicate skin irritation (GPMT, Acute dermal toxicity study and QSAR ToxTree) and eye damage (BCOP)       

Eye irritation/damage: Eye damage (BCOP, OECD 437, GLP, rel.1, K).

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02-03 September 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 430 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test Method (TER))

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

UK GLP Compliance Programme (inspected on June 17, 2015 / signed on September 24, 2015)

Specific details on test material used for the study:

Storage condition of test material: Room temperature in the dark

Test system:

isolated skin discs

Source species:

rat

Source strain:

Wistar

Details on animal used as source of test system:

TEST ANIMALS
- Strain: Wistar (RccHan™:WIST)
- Source: Envigo RMS (UK) Limited, Oxon, UK.
- Sex: female
- Age at the start of pelt preparation: 21-23 days
- Housing: Animal was housed in a suspended solid-floor polypropylene cage furnished with woodflakes.
- Diet: Food (2014C Teklad Global Rodent diet supplied by Envigo RMS (UK) Limited, Oxon, UK), ad libitum
- Water: Mains drinking water, ad libitum
- Acclimatization period: 2 days

ENVIRONMENTAL CONDITIONS
- Temperature: 19-25 °C
- Humidity: 30-70 %
- Air changes: At least fifteen changes per hour
- Photoperiod: 12 h dark / 12 h light

Justification for test system used:

Following the REACH bottom-up strategy, the Transcutaneous Electrical Resistance Assay was used to assess skin corrosion as recommended in the OECD test guideline No. 439. This method was chosen because the registered substance was considered incompatible with the EpiDerm™ skin corrosivity test due to non-specific reduction of MTT by the test substance.

Vehicle:

unchanged (no vehicle)

Details on test system:

SKIN DISC PREPARATION
- Procedure used: Following an acclimatization period of 2 days the animal was shaved to remove hair from the dorsal surface and skin area was washed using an antibiotic wash. After 3 days a second antibiotic wash was performed. Two days later the animal was killed using ascending concentrations of carbon dioxide followed by cervical dislocation. The dorsal skin was removed from the rat as a single pelt. Excess fat was removed and the pelt mounted, epidermal side uppermost, onto a polytetrafluoroethylene (PTFE) tube. The tissue was secured in place using a rubber “O” ring. Excess tissue was trimmed away and the “O” ring/PTFE interface sealed with soft paraffin wax. The tube was supported by a clamp inside a labelled 30 mL glass receptacle containing 10 mL electrolyte solution (154 mM MgSO4).
- Quality control for skin discs: Electrical resistance obtained with two of the isolated skin discs was greater than 10 kΩ in order for the remainder of the pelt to be used in the assay

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 20 to 23°C

REMOVAL OF TEST MATERIAL AND CONTROLS
- Number of washing steps: not reported. At the end of the exposure period, the test item was removed by washing the skin disc with a jet of warm tap water until no further test item could be removed
- Observable damage in the tissue due to washing: no obvious damage reported
- Modifications to validated SOP: none reported

DYE BINDING METHOD
- Dye used in the dye-binding assay: None (Dye penetration is assessed only if the mean TER value of the test item is less than or equal to 5 kΩ)

NUMBER OF INDEPENDENT TESTING RUNS / EXPERIMENTS TO DERIVE FINAL PREDICTION: 1

PREDICTION MODEL / DECISION CRITERIA
- The test substance is considered to be corrosive to skin if the mean TER value is less than or equal to 5 kΩ and the skin disk is obviously damaged, or if the mean TER value is less than or equal to 5 kΩ, and the skin disc is showing no obvious damage, but the mean disc dye content is greater than or equal to the mean disc dye content of the 10M HCl positive control obtained concurrently.
- The test substance is considered to be non-corrosive to skin if the mean TER value obtained for the test substance is greater than 5 kΩ, or if the mean TER value is less than or equal to 5 kΩ, and the skin disc is showing no obvious damage, and the mean disc dye content is well below the mean disc dye content of the 10M HCl positive control obtained concurrently.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 150 μL of test item was applied to the inner epidermal surface of skin discs using an automatic pipettor
- Concentration (if solution): undiluted

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 150 μL
- Concentration (if solution): Sterile distilled water

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 150 μL
- Concentration (if solution): 10M hydrochloric acid (approximately 36%)

Duration of treatment / exposure:

Test item was applied to the epidermal surface of three skin discs for a contact period of 24 hours.

Number of replicates:

Total: 9 skin discs - 3 skin discs/group for test item, negative and positive controls

Irritation / corrosion parameter:

transcutaneous electrical resistance (in kΩ)

Run / experiment:

24 hours exposure period

Value:

9.3

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: No indication of corrosion

Other effects / acceptance of results:

- OTHER EFFECTS:
- Visible damage on test system: no

DEMONSTRATION OF TECHNICAL PROFICIENCY: yes

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes (20.6 kΩ)
- Acceptance criteria met for positive control: yes (860.3 Ω)
- Acceptance criteria met for variability between replicate measurements: yes

Table 7.3.1/1: Individual and mean transcutaneous electrical resistance measurements

 

Treatment	Tissue Number	TER (kΩ)	Mean TER ± SD(kΩ)
Test Item	1	10.5	9.3 ± 2.0
	2	7.0
	3	10.4
Positive Control	4	0.909	0. 8603 ± 0.00485
	5	0.812
	6	0.860
Negative Control	7	15.3	20.6 ± 8.0
	8	29.8
	9	16.6

Interpretation of results:

GHS criteria not met

Conclusions:

Under the test conditions, with a mean TER of 9.3 kΩ (> 5 kΩ) the test item was considered to be non-corrosive to skin according to the Regulation (EC) No. 1272/2008 (CLP) and to the GHS.

Executive summary:

An in vitro skin irritation study was performed according to the OECD Guideline 430 and in compliance with GLP, using the Transcutaneous Electrical Resistance (TER) Assay. The test item (150 μL) was applied to the epidermal surface of three skin discs for a contact period of 24 hours. At the end of the exposure period, the test item was removed by washing the skin disc with a jet of warm tap water until no further test item could be removed. The positive control was 10M hydrochloric acid (approximately 36%) and the negative control was sterile distilled water. The contact period for the positive and negative controls was 24 hours. The TER was measured using a Wheatstone Bridge with a low voltage alternating current and mean TER for the skin discs was calculated.

 

The mean TER recorded for the test item was 9.3 kΩ. The mean TER recorded for the positive and negative control discs were as follows: Positive control disc, 10M Hydrochloric acid (approximately 36%): 860.3 Ω and Negative control disc, Sterile distilled water: 20.6 kΩ. The mean TER values for the positive and negative control discs were within the acceptable range for the method, and the variability between skin disc replicates was considered to be acceptable, therefore the test results were considered to be valid.

 

Under the test conditions, with a mean TER of 9.3 kΩ (> 5 kΩ)  the test item was considered to be non-corrosive to skin according to the Regulation (EC) No. 1272/2008 (CLP) and to the GHS.

Reference 2

Endpoint:

skin irritation: in vivo

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Reference 1

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11-12 November 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying Ocular Corrosives and Severe Irritants)

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

UK GLP Compliance Programme (inspected on July 01-03, 2014 / signed on September 15, 2014)

Specific details on test material used for the study:

Storage: room temperature in the dark

Species:

cattle

Strain:

not specified

Details on test animals or tissues and environmental conditions:

SOURCE OF COLLECTED EYES
- Source: supplied by Joseph Morris Abattoir, were excised by an abattoir employee and collected as soon after slaughter as possible (last excised at 13:00 hours, 11 November 2014).
- Number of animals: not reported
- Characteristics of donor animals (e.g. age, sex, weight): cattle aged between 24 – 30 months
- Storage, temperature and transport conditions of ocular tissue (e.g. transport time, transport media and temperature, and other conditions): Instructions were given to avoid damaging the corneas during excision. Excised eyes were maintained and transported to the laboratory, at ambient temperature, in sufficient HBSS, containing 1% (v/v) penicillin/streptomycin solution, to cover all the eyes in the receptacle.
- Time interval prior to initiating testing: The eyes were used within 4 hours of slaughter (incubation of mounted corneas commenced at 14:48 hours, 11 November 2014).
- indication of any existing defects or lesions in ocular tissue samples: none reported ; Instructions were given to avoid damaging the corneas during excision.
- Indication of any antibiotics used: HBSS containing 1% (v/v) penicillin/streptomycin solution

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 750 μL of test item was applied on each cornea.
- Concentration (if solution): The test item was tested undiluted.
- The pH of the test substance was approximately 7.0.

Duration of treatment / exposure:

10 minutes (± 30 seconds) at 32 ± 1 °C in horizontal position.

Duration of post- treatment incubation (in vitro):

2 hours ±10 minutes at 32 ± 1 °C in a vertical position.

Number of animals or in vitro replicates:

Total: 9 corneas - 3 corneas/group for test item, negative and positive controls

Details on study design:

SELECTION AND PREPARATION OF CORNEAS
All eyes were carefully examined, macroscopically, for defects (opacity, scratches, pigmentation, cuts, etc.) and those exhibiting defects were discarded. The tissue surrounding the eyeball was carefully pulled away and the cornea dissected leaving approximately 2 to 3 mm of sclera present around the cornea.
The isolated corneas were stored in a petri dish containing HBSS plus 1% penicillin/streptomycin solution until all the corneas had been dissected. Once all the corneas had been dissected, they were rinsed in fresh HBSS plus 1% penicillin/streptomycin solution prior to mounting.
The corneas were mounted in the cornea holders with the endothelial side against the O-ring of the posterior half of the holder. The anterior half of the holder was then positioned on top of the cornea and secured with screws. Both compartments of the holder were filled with HBSS plus 1% (v/v) penicillin/streptomycin, using a syringe. The posterior compartment was always filled first to return the cornea to its natural shape. The holders were then plugged and incubated, in an upright position, overnight at room temperature (approximately 20 °C). After overnight incubation at room temperature (approximately 20°C) the HBSS plus 1% (v/v) penicillin/streptomycin was removed from both chambers. Both chambers were filled with cMEM (posterior chamber first), taking care to exclude air bubbles and plugged. For equilibration, the corneas in the holder were incubated in the upright position for 60 minutes ± 5 minutes at 32 ± 1 °C in a water-bath. At the end of the 60 minutes incubation period, the medium was removed and refilled with fresh cMEM and then, the basal opacity was determined.

QUALITY CHECK OF THE ISOLATED CORNEAS : Throughout the assay the corneas were examined for opaque spots or other irregularities.

NUMBER OF REPLICATES : 3 corneas/group

NEGATIVE CONTROL USED : 0.9% sodium chloride solution

POSITIVE CONTROL USED : Ethanol

APPLICATION DOSE AND EXPOSURE TIME : The anterior compartment received the test item or negative or positive control at a volume of 750 μL on the surface of the corneas. The corneas were incubated in a horizontal position for 10 minutes (± 30 seconds) at 32 ± 1 °C in the water-bath.

TREATMENT METHOD: closed chamber

POST-INCUBATION PERIOD: no

REMOVAL OF TEST SUBSTANCE
- Number of washing steps after exposure period: at least three times or until the wash medium (EMEM with phenol red) was clear and there was no discolouration. The test substance required three washes.
- POST-EXPOSURE INCUBATION: yes, after the test item was rinsed off from the application site by washing, the corneas were incubated at 32 ± 1 °C for 2 hours ± 10 minutes in an upright position.

METHODS FOR MEASURED ENDPOINTS:
- Corneal opacity: The opacitometer measured the light transmission through the centre of each mounted cornea, displaying a numerical opacity value (arbitrary unit). The opacity of each cornea was measured by reading each holder in the right-hand chamber of the calibrated opacitometer. Corneas with an opacity value greater than 7 units were discarded. The mean basal opacity value of the corneas was then calculated and three corneas with opacity values close to the mean value were chosen for use as negative control corneas.
- Corneal permeability: passage of sodium fluorescein dye measured with the aid of UV/VIS spectrophotometry (OD490). Following the final opacity measurement, the incubation medium was removed from the anterior compartment of the holder and replaced by 1 mL of sodium fluorescein solution (4 mg/mL). Corneas were incubated again in a horizontal position for 90 ± 5 minutes in a water-bath at 32 ± 1 °C. Incubation medium from the posterior compartment was removed, well mixed and transferred to a 1 cm path length cuvette and the optical density at 490 nm (OD490) was determined with a spectrophotometer.
- Others (e.g, pertinent visual observations, histopathology): Throughout the assay the corneas were examined for opaque spots or other irregularities. Moreover an estimate of the pH of the test substance as 10% v/v solution in 0.9% sodium chloride solution, was determined using pH test sticks and recorded.

SCORING SYSTEM: In Vitro Irritancy Score (IVIS)

DECISION CRITERIA: the decision criteria as indicated in the TG was used.

Irritation parameter:

in vitro irritation score

Run / experiment:

mean/3 corneas incubated 2 hours

Value:

71.8

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Other effects / acceptance of results:

OTHER EFFECTS:
- Visible damage on test system: Following treatment with test substance, the corneas were noted as opaque with very opaque areas. The corneas treated with the positive control, ethanol, were opaque and the corneas treated with the negative control, 0.9% saline, were clear.

DEMONSTRATION OF TECHNICAL PROFICIENCY: yes

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
- Acceptance criteria met for positive control: yes
- Range of historical values if different from the ones specified in the test guideline:
The positive control should elicit an In Vitro Irritancy Score that falls within two standard deviations of the historical mean (2 x SD 26.4 to 49.0) for the laboratory.
The negative control mean opacity change value should be ≤3.0 and the permeability mean value ≤0.1 (assays performed from November 2007 to October 2014).

Other effects:

None

Table 7.3.2/1: Individual and Mean Corneal Opacity and Permeability Measurements

Treatment	Cornea Number	Opacity					Permeability (OD)		In vitro irritancy Score ± SD
		Pre-Treatment	Post-Treatment	Post-Incubation	Post-Incubation-Pre‑Treatment	Corrected Value		Corrected Value
Negative Control	2	3	-	4	1		0.015
	3	3	-	3	0		0.022
	5	3	-	3	0		0.010
	Mean ± SD				0.333 ± 0.577		0.016 ± 0.006
Positive Control	1	2	-	21	19	18.667	1.098	1.082
	4	5	-	24	19	18.667	1.263	1.247
	6	6	-	30	24	23.667	1.336	1.320
	Mean± SD					20.333 ± 2.887		1.217 ± 0.122	38.6 ± 4.4
Test Item	7	4	-	29	25	24.667	3.650	3.634
	8	3	-	34	31	30.667	3.370	3.354
	9	4	-	22	18	17.667	2.525	2.509
	Mean± SD					24.333 ± 6.506		3.166 ± 0.586	71.8 ± 14.3

ASSAY VALIDITY

The positive control, ethanol, elicited an In Vitro Irritancy Score of 38.6. This value was within the historical range (mean ± 2 x SD = 26.4 – 49.0) for the assays performed to date.

The negative control, 0.9% saline, opacity mean change value was 0.333 which was below the maximum acceptance value of 3.0. The permeability mean of the negative control was 0.016, which was below the maximum acceptance value of 0.1.

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Conclusions:

The test substance is identified as inducing serious eye damage. It is therefore classified as Eye damage Category 1 (H318: Causes serious eye damage) according to the Regulation (EC) No 1272/2008 (CLP) and to the GHS.

Executive summary:

An in vitro eye irritation study was performed according to the OECD Guideline 437 and in compliance with GLP to assess the corneal damage potential of test substance by means of the BCOP assay using fresh bovine corneae.  750 µL of test item was applied to corneae for 10 minutes followed by an incubation period of 2 hours at 32 ± 1 °C and corneal opacity was measured. Three corneas were used for each treated series (undiluted test item; negative control; positive control: ethanol). Following the opacity measurement the permeability of the corneas to sodium fluorescein was evaluated. Two endpoints, corneal opacity and permeability, were measured and combined to give an In Vitro Irritancy Score.

 

Following treatment with test substance, the corneas were noted as opaque with very opaque areas. The corneas treated with the positive control, ethanol, were opaque and the corneas treated with the negative control, 0.9% saline, were clear. The negative and positive controls met the acceptance criteria for this assay. The calculated mean in vitro irritancy score for test substance and positive control were 71.8 ± 14.3 and 38.6 ± 4.4, respectively.

 

The test substance is identified as inducing serious eye damage. It is therefore classified as Eye damage Category 1 (H318: Causes serious eye damage) according to the Regulation (EC) No 1272/2008 (CLP) and to the GHS.

Reference 2

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

From July 18 to August 10, 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Study conducted according to OECD Guideline No. 405 with acceptable deviations. GLP compliance not reported. One animal, tested with 5 µL instead of 0.1 mL. Under the test conditions, the test material is suspected to be corrosive to the eyes. As a consequence, further in vitro testing was conducted to conclude on eye corrosion classification..

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

yes

Remarks:

Dose of 5 µM instead of 0.1 mL. Purity of test item not reported, Environmental condition of animal room not reported, body weight at end of the study not reported.

Principles of method if other than guideline:

Not applicable

GLP compliance:

not specified

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Age at study initiation: 8 weeks
- Weight at study initiation: 2.18 kg
- Housing: Animals were housed individually in cages with wire mesh floors.
- Diet: Certified pelleted commercial rabbit diet, ad libitum
- Water: Tap water, ad libitum

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 5 µL
- Concentration: 100 %

Duration of treatment / exposure:

Eyes of the animals were not rinsed.

Observation period (in vivo):

1, 2, 3, 4, 5, 8, 10 and 12 days following instillation of test material.

Number of animals or in vitro replicates:

1 male

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): No

SCORING SYSTEM: According to ‘Draize scale’

TOOL USED TO ASSESS SCORE: Slit lamp/fluorescein

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 8 days

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 8 days

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

3

Reversibility:

fully reversible within: 12 days

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.7

Max. score:

4

Reversibility:

fully reversible within: 3 days

Irritant / corrosive response data:

- The animal showed signs of acute pain on treatment.
- The eye subsequently showed the loss of an extensive area of corneal epithelium together with severe corneal swelling. Calculated corneal swelling was found to be 81, 51, 47, 32, 19, 15 and 15 % at Days 2, 3, 4, 5, 8, 10 and 12, respectively.
- The eye also showed moderate conjunctivitis and iritis.
- The eye had healed to normality by Day 12.

Other effects:

None

Table 7.3.2/1: Eye irritation response data of one rabbit at each observation time

Score at time point / Reversibility	Cornea		Iris (/2)	Conjunctivae
	Opacity (/4)	Area (/4)		Redness (/3)	Chemosis (/4)	Discharge (/3)
Day 1 (15 min)	-	-	-	1	1	-
Day 2 (24 h)	1	4	1	1	2	1
Day 3 (48 h)	1	3	1	1	0	0
Day 4 (72 h)	1	2	1	1	0	0
Day 5	1	1	1	1	0	0
Day 8	0	0	0	1	0	0
Day 10	0	0	0	1	0	0
Day 12	0	0	0	0	0	0
Average 24, 48 and 72 h	1	3	1	1	0.7	0.3
Reversibility	Completely reversible	Completely reversible	Completely reversible	Completely reversible	Completely reversible	Completely reversible
Average time for reversion	8 days	8 days	8 days	12 days	3 days	3 days

 

Note: Treatment day considered as Day 1

Interpretation of results:

corrosive

Conclusions:

Under the test conditions, the test material is suspected to be corrosive to the eyes. As a consequence, further in vitro testing was conducted to conclude on eye corrosion classification.

Executive summary:

In a non-GLP eye irritation study performed similarly to OECD TG405, 5 µL of test material was instilled into one eye of one New Zealand White rabbit by gently pulling the lower eyelid away from the eyeball. The eye was not rinsed after the instillation of test material. The animal was observed on the day of instillation (D1, at 15 minutes) for conjunctival reactions after instillation of test material into eyes and then on Days 2, 3, 4, 5, 8, 10 and 12 for the reactions in the conjunctivae, the iris and the cornea and graded according to the ‘Draize method’. Corneal thickness was measured and percentage corneal swelling was calculated.

The animal showed signs of acute pain on treatment. The eye subsequently showed the loss of an extensive area of corneal epithelium together with severe corneal swelling (81, 51, 47, 32, 19, 15 and 15 % at Days 2, 3, 4, 5, 8, 10 and 12, respectively). The eye also showed moderate conjunctivitis and iritis. The eye had healed to normality by Day 12.

Under the test conditions, the test material is suspected to be corrosive to the eyes. As a consequence, further in vitro testing was conducted to conclude on eye corrosion classification.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

Skin irritation:

Since no key study was identified on the registered substance, the testing and assessment strategy, as described in ECHA R.7a Endpoint specific guidance (July 2015), was used to evaluate the skin corrosion/irritation potential of the registered substance:

	Element	Information	Conclusion	Comments
Existing data on physico - chemical properties	1a	Is the substance spontaneously flammable in contact with air (pyrophoric) or water at room temperature?	NO
	1b	Is the substance an organic hydroperoxide or an organic peroxide?	NO
	1c	Is the pH of the substance ≤ 2.0 or ≥ 11.5?	NO
	1d	Are there other physical or chemical properties that indicate that the substance is corrosive/irritant?	NO
Existing human data	2	Are there adequate existing human data which provide evidence that the substance is a corrosive or irritant?	NO
Existing animal data from corrosion/irritation studies	3	Are there data from existing studies on corrosion and irritation in laboratory animals, which provide sound conclusive evidence that the substance is a corrosive, irritant or non-irritant?	NO
Existing data from general toxicity studies via the dermal route and from sensitisation studies	4a	Is the substance classified as fatal in contact with skin (LD50 ≤ 50 mg/kg bw, CLP hazard statement H310)	NO	Dermal LD50 > 2000 mg/kg bw
	4b	Has the substance proven to be a corrosive, irritant or non-irritant in a suitable acute dermal toxicity test?	NO	Dermal irritation was reported in an acute dermal toxicity test, but scores were not reported and the study was poorly reliable, therefore a conclusion was not possible
	4c	Has the substance proven to be a corrosive or an irritant in sensitisation studies or after repeated exposure?	NO	GPMT available: Slight irritation was observed at 100%
Existing/new (Q)SAR data and read -across	5a	Are there structurally related substances (suitable “read-across” or grouping), which are classified as corrosive to the skin (Skin Corrosive Cat. 1), or do suitable (Q)SAR methods indicate corrosion potential of the substance?	YES	Predicted to be "Irritating or Corrosive to Skin" using Toxtree (v2.6.6). Predicted to be "‘Corrosive to skin >> Phenols///Irritating to skin///Irritating to skin >> Ethers///Irritating to skin >> Substituted phenols/naphthols" using OASIS TIMES (v2.27.17).
	5b	Are there structurally related substances (suitable “read-across” or grouping), which are classified as irritant to the skin (Skin Irritant Cat. 2), or indicating that the substance is non-irritant, or do suitable (Q)SAR methods indicate irritant or non-irritant potential of the substance?	NO
Existing in vitro data	6a	Has the substance demonstrated corrosive properties in an EU/OECD adopted in vitro test? Data from in vitro test methods that have been validated and are considered scientifically valid but are not yet adopted by EU and/or OECD may also be used if the provisions defined in Annex XI are met	YES	BCOP available: the substance was classified as corrosive to the eyes
	6b	Has the substance demonstrated irritant or non-irritant properties in an EU/OECD adopted in vitro test? Data from in vitro test methods that have been validated and are considered scientifically valid but are not yet adopted by EU and/or OECD may also be used if the provisions defined in Annex XI are met.	NO
	6c	Are there data from a non-validated suitable in vitro test(s), which provide sound conclusive evidence that the substance is corrosive/ irritant?	NO	(at the initiation of the dossier, no test was available)
Weight-of- Evidence analysis	7	The “elements” described above may be arranged as appropriate. Taking all available existing and relevant data mentioned above (Elements 1-6) into account, is there sufficient information to make a decision on whether classification/labelling is necessary, and –if so –how to classify and label?	NO
New in vitro test for corrosivity	8	Does the substance demonstrate corrosive properties in (an) EU/OECD adopted in vitro test(s) for skin corrosion?	YES	Based on all available data (ATD, GPMT, QSARs), the substance is considered at least as a skin irritant and an eye corrosive (BCOP) => a TER assay for corrosion was initiated. The conclusion of this TER test is sufficient to conclude on C&L (TER value > 5 kΩ (9.3 kΩ) <=> Not a skin corrosive)
New in vitro test for irritation	9	Does the substance demonstrate irritating or non-irritating properties in (an) EU/OECD adopted in vitro test(s) for skin irritation?	NO	Based on all available data (ATD, GPMT, QSARs, TER assay), the substance is considered as a skin irritant => no further test was needed
New in vivo test for corrosion/irritation	10	To be used only as a last resort	NO

Available data indicate that undiluted Dihydroeugenol is irritant to animal skin and corrosive to the eye. Therefore, an in vitro test for corrosivity was performed on Dihydroeugenol (HLS, 2015, Rel.1). In this Transcutaneous Electrical Resistance (TER) Assay, the mean TER value was 9.3 kΩ, i.e. greater than the limit of 5 kΩ fixed in the OECD Test Guideline No. 430. Dihydroeugenol is considered to be non-corrosive to skin. Based on clear signs of skin irritation in the acute dermal toxicity study and in the GPMT together with QSAR results, Dihydroeugenol is classified as skin irritant without further in vivo testing.

Eye irritation:

In a non-GLP eye irritation study performed similarly to OECD TG405 (URL, 1988, Rel.2), 5 µL of test material was instilled into one eye of one New Zealand White rabbit by gently pulling the lower eyelid away from the eyeball. The eye was not rinsed after the instillation of test material. The animal was observed on the day of instillation (D1, at 15 minutes) for conjunctival reactions after instillation of test material into eyes and then on Days 2, 3, 4, 5, 8, 10 and 12 for the reactions in the conjunctivae, the iris and the cornea and graded according to the ‘Draize method’. Corneal thickness was measured and percentage corneal swelling was calculated.The animal showed signs of acute pain on treatment. The eye subsequently showed the loss of an extensive area of corneal epithelium together with severe corneal swelling (81, 51, 47, 32, 19, 15 and 15 % at Days 2, 3, 4, 5, 8, 10 and 12, respectively).The eye also showed moderate conjunctivitis and iritis. The eye had healed to normality by Day 12.Under the test conditions, the test material was suspected to be corrosive to the eyes.

As a consequence, further in vitro testing was conducted to conclude on eye corrosion classification

	Element	Information	Conclusion	Comments
Conclusion of the information strategy on skin corrosion/irritation	0	Is the substance classified as a skin corrosive?	NO	Skin irritant Category 2
Existing data on physico - chemical properties	1a	Is the substance spontaneously flammable in contact with air (pyrophoric) or water at room temperature?	NO
	1b	Is the substance an organic hydroperoxide or an organic peroxide?	NO
	1c	Is the pH of the substance ≤ 2.0 or ≥ 11.5?	NO
	1d	Are there other physical or chemical properties that indicate that the substance causes serious eye damage or eye irritation?	NO
Existing human data	2	Are there adequate existing human data which provide evidence that the substance has the potential to cause serious eye damage or eye irritation?	NO
Existing animal data from corrosion/irritation studies	3	Are there data from existing studies on corrosion and irritation in laboratory animals, which provide sound conclusive evidence that the substance is a corrosive, irritant or non-irritant?	NO
Existing/new (Q)SAR data and read-across	4	Are there structurally related substances (suitable “read-across” or grouping), which are classified as causing serious eye damage/eye irritation, or indicating that the substance is non-irritant, or do valid (Q)SAR methods indicate serious eye damage/eye irritation or non-irritation of the substance?	NO	"Unknown" class using Toxtree (v2.6.6).
Existing in vitro data	5a	Has the substance demonstrated serious eye damage, eye irritation or non-irritating properties in an EU/OECD adopted in vitro test? Data from in vitro test methods that have been validated and are considered scientifically valid but are not yet adopted by EU and/or OECD may also be used if the provisions defined in Annex XI are met.	NO
	5b	Are there acceptable data from (a) non-validated suitable in vitro test(s), which provide sound evidence that the substance causes serious eye damage/eye irritation?	NO	(at the initiation of the dossier, no test was available)
Weight-of- Evidence analysis	6	The “elements” described above may be arranged as appropriate. Taking all available existing and relevant data mentioned above (Elements 0 – 5) into account, is there sufficient information to make a decision on whether classification/labelling is necessary, and – if so – how to classify and label?	NO
New in vitro tests for serious eye damage/eye irritation (Annex VII to the REACH Regulation)	7a	Does the substance demonstrate serious eye damage, eye irritation or non-irritant properties in (an) EU/OECD adopted in vitro test(s) for the eye hazard charaterisation? Data from in vitro test methods that have been validated and are considered scientifically valid but are not yet adopted by EU and/or OECD may also be used if the provisions of Annex XI are met.	NO
	8b	Does the substance demonstrate serious eye damage or eye irritant properties in (a) non-validated suitable in vitro test(s) for serious eye damage/eye irritation?	NO	=> an BCOP assay was initiated. The conclusion of this test is: corrosive to the eyes (IVIS = 71,8)
New in vivo test for serious eye damage/eye irritation as a last resort (Annex VIII to the REACH Regulation)	8b	Does the substance demonstrate serious eye damage or eye irritation in an OECD adopted in vivo test?	NO	The in vitro test was conclusive, an vivo testing was not needed.

A BCOP assay (HLS, 2015, Rel.1) was conducted according to the OECD guideline No. 437 and in compliance with GLP. The quality criteria required for acceptance of results in the test were satisfied. The In Vitro Irritancy Score of the test item was 71.8, after the 10 -minute exposure period followed by 120 -minute incubation period. With an IVIS > 55, the test substance is predicted to be corrosive to the eyes.

Justification for classification or non-classification

Harmonized classification:

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

Self-classification:

Based on the available information on the substance and on the supporting substance, the registered substance should be classified as Skin irr. Category 2 (H315: Causes skin irritation) according to the Annex VI of the Regulation (EC) No. 1272/2008 (CLP) and to the GHS.

 

Based on the available information on the supporting substance, the registered substance should be classified as Eye Damage Category 1: Causes serious eye damage according to the Annex VI of the Regulation (EC) No. 1272/2008 (CLP) and to the GHS.

 

No study was available regarding respiratory irritation. However, based on the classification for skin and eye irritation, the substance should be classified by default and as a worst-case as STOT-SE Category 3 (H335: May cause respiratory irritation) according to the Annex VI of the Regulation (EC) No. 1272/2008 (CLP).