2-methyl-1-phenylpropan-2-ol

Endpoint summary

Description of key information

Skin corrosion: Not corrosive (OECD 431/GLP)

Skin irritation: Not irritating (OECD 439/GLP)

Read-across from PEA - Serious eye damage/eye irritation (in vivo): Irritating

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:

From 08-08-2017 to 22-02-2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Yinghai (Cangzhou) Aroma Chemical Company Ltd./CP001-170601
- Expiration date of the lot/batch: June 1, 2018
- Purity: 99.7 % w/w


STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Controlled room temperature (15-25 °C, ≤ 70 RH%), protected from humidity and light.

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Vehicle:

unchanged (no vehicle)

Details on test system:

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 4 hours (±10 min) at room temperature (23.4-24.6°C) covered with the plate lids.

REMOVAL OF TEST MATERIAL AND CONTROLS
- Number of washing steps: Tissues were thoroughly rinsed with PBS solution to remove the test substance/controls.
- Observable damage in the tissue due to washing: without touching the epidermis
- Modifications to validated SOP: None

DYE BINDING METHOD
- Dye used in the dye-binding assay: MTT
- Spectrophotometer: plate reader
- Wavelength: 570 nm

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 50 µL

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 μL H2O


POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50 μL
- Concentration (if solution): 8N KOH

Duration of treatment / exposure:

4 hours (±10 min) at room temperature (23.4-24.6°C) covered with the plate lids.

Number of replicates:

2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

240 minutes

Value:

41.4

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

- OTHER EFFECTS:
- Direct-MTT reduction: After three hours of incubation, yellow colour of the mixture was detected; therefore additional controls were not used in the experiment.
- Colour interference with MTT: As no coloured solution was detected and the test item had no intrinsic colour, no additional colour controls were needed in the experiment to determine the Non Specific Colour (the test item showed no ability to stain the epidermis).


ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: The mean OD value of the two negative control tissues (0.843) was in the recommended range of 0.6 and 1.5.
- Acceptance criteria met for positive control: The two positive control treated tissues showed 0.6% viability, which is in the recommended range of 0 – 20%, demonstrating the proper performance of the assay.
- Acceptance criteria met for variability between replicate measurements:The difference of viability between the two negative control tissue samples in the MTT assay was 1.2% which meets the criteria not exceeding 30%.

Interpretation of results:

GHS criteria not met

Conclusions:

In conclusion, in this in vitro EPISKIN™(SM) model test with dimethyl benzyl carbinol, the results indicate that the test item is non-corrosive to the skin.

Executive summary:

In an in vitro skin corrosion assay in a human epidermal model EPISKINTM (SM) (17/236-039B), reconstructed human epidermis tissue was exposed to 50 µL of DMBC (99.7%) for 4 hours (±10 min). Physiological saline (0.9% (w/v) NaCl solution) was used for the negative control and glacial acetic acid was used for the positive control. After removal of the test substance, tissues were washed with PBS. Three hours incubation with MTT and an overnight isopropyl alcohol extraction period followed. The OD570 of isopropyl alcohol extracts was measured on a spectrophotometer. Relative cell viability was calculated for each tissue as % of the mean viability of the negative control tissues.

The colour of the test substance did not interfere with the endpoint. The test substance is not directly MTT reducing. The average viability of tissues treated by the test substance DMBC was 41.4% compared to the negative control i.e. viability was > 35%. The average viability of tissues treated by the positive control was 0.6 % of negative control average value. According to these results, the test substance is not corrosive.

This in vitro skin corrosion study in the human epidermal model EPISKINTM (SM) is acceptable and satisfies the guideline requirement for an OECD 431 study.

Reference 2

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 31-08-2017 to 12-02-2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Yinghai (Cangzhou) Aroma Chemical Company Ltd./CP001-170601
- Expiration date of the lot/batch: June 1, 2018
- Purity: 99.7 % w/w


STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Controlled room temperature (15-25 °C, ≤ 70 RH%), protected from humidity and light.

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Vehicle:

unchanged (no vehicle)

Details on test system:

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 15 minutes (± 0.5 min) at room temperature (24.3-26.2°C)
- Temperature of post-treatment incubation (if applicable): 37°C

REMOVAL OF TEST MATERIAL AND CONTROLS
- Number of washing steps: Tissues are then thoroughly rinsed with PBS
- Modifications to validated SOP: None

DYE BINDING METHOD
- Dye used in the dye-binding assay: MTT
- Spectrophotometer:plate reader
- Wavelength:570 nm
- Filter: No external filter was used

Control samples:

yes, concurrent no treatment

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 10 µL of substance/surface ratio 26 µL/cm2

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 µL

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50 µL
- Concentration (if solution):5% (w/v) SDS in water

Duration of treatment / exposure:

15 minutes (± 0.5 min) at room temperature (24.3-26.2°C).

Duration of post-treatment incubation (if applicable):

After rinsing the units were placed into the plate wells with fresh pre-warmed Maintenance Medium (2 mL/well) below them and then incubated for 42 hours (± 1h) at 37°C in an incubator with 5% CO2, in a >95% humidified atmosphere

Number of replicates:

3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

15 minutes

Value:

66.5

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

- OTHER EFFECTS:
- Direct-MTT reduction: After three hours incubation, purple precipitate of the mixture was detected in the test tube. Thus, the test item reacted with MTT and therefore the use of additional controls was necessary.
- Colour interference with MTT: As no coloured solution was detected and the test item had no intrinsic colour, no additional colour controls were needed in the experiment to determine the Non Specific Colour (the test item showed no ability to stain the epidermis).


ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: The mean OD570 of the NC tissue was 0.674 which meets the acceptance criteria of ≥ 0.6 and ≤ 1.5. Standard deviation of the viability results for negative control samples was 1.3% which meets the acceptance criteria of ≤ 18%.
- Acceptance criteria met for positive control: The mean viability of the PC tissues expressed as % of the negative control tissues is 5.3% which meets the acceptance criterion of ≤ 40 %. The standard deviation value (SD) of 0.8% which meets the acceptance criteria of ≤ 18%.
- Acceptance criteria met for variability between replicate measurements: The SD calculated from individual % tissue viabilities of the 3 identically treated replicates for the positive control, negative control and test substance is ≤18 %.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the above-described experimental design, the test substance dimethyl benzyl carbinol was not an irritant in the in vitro skin irritation test on human epidermal EpiDermTM tissues.

Executive summary:

In an in vitro skin irritation assay in a human epidermal model EPISKINTM (SM) (17/236-043B), reconstructed human epidermis tissue was exposed to 10 µL of DMBC (99.7%) for 15 minutes (± 0.5 min). PBS was used for the negative control and 5% SDS was used for the positive control. After removal of the test substance, tissues were post-incubated for approximately 42 hours. Three hours incubation with MTT and a 2-hour isopropyl alcohol extraction period followed. The OD570 of isopropyl alcohol extracts was measured on a spectrophotometer. Relative cell viability was calculated for each tissue as % of the mean viability of the negative control tissues.

The colour of the test substance did not interfere with the endpoint. The test substance is directly MTT reducing. The average viability of tissues treated by the test substance DMBC was 66.5% compared to the negative control (after adjustment for non-specific MTT reduction) i.e. viability was > 50 %. The average viability of tissues treated by the positive control (5% SDS) was 5.3 % of negative control average value. According to these results, the test substance is not irritating.

This in vitro skin irritation study in the human epidermal model EPISKINTM (SM) is acceptable and satisfies the guideline requirement for an OECD 439 study.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Reference 1

Endpoint:

eye irritation: in vitro / ex vivo

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

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

Reference 2

Endpoint:

eye irritation: in vivo

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please see the below Attached justification.

Reason / purpose for cross-reference:

read-across source

Irritation parameter:

other: cornela necrosis

Basis:

mean

Time point:

other: Only 24 hr timepoint

Score:

8

Max. score:

10

Reversibility:

not specified

Remarks on result:

positive indication of irritation

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Reversibility:

not specified

Remarks on result:

not measured/tested

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Reversibility:

not specified

Remarks on result:

not measured/tested

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Reversibility:

not specified

Remarks on result:

not measured/tested

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Reversibility:

not specified

Remarks on result:

not measured/tested

Interpretation of results:

other: Irritating

Conclusions:

Phenylethyl Alcohol is an irritant to rabbit eyes.

Executive summary:

In an eye irritation study (Carpenter et al., 1974) Phenylethyl Alcohol (undiluted) was applied to the centre of the cornea of 5 albino rabbits. The eye was examined in strong diffuse daylight 18 - 24 hours later, stained with fluorescein, and the injury scored. No vehicle was used.

Eye injury was graded according to the following 10-point scale based upon the degree of corneal necrosis that resulted. The corneal injury in rabbits was indicated as 8 out of 10. Based on the results of this study, Phenylethyl Alcohol was considered to be an eye irritant.

Reference 3

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

no guideline followed

Principles of method if other than guideline:

The method is described in Smyth et al., 1962 and Carpenter and Smyth 1946. Eye irritation was evaluated using 5 albino rabbits per dose. The test material was applied to the centre of the cornea while the lids are retracted, and approximately 1 minute later, the lids are released. The eye was examined in strong diffuse daylight 18 - 24 hours later, stained with fluorescein, and the injury scored. No vehicle was used.

GLP compliance:

no

Species:

rabbit

Strain:

not specified

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

Undiluted

Duration of treatment / exposure:

18 - 24 hours

Irritation parameter:

other: corneal necrosis

Basis:

mean

Time point:

other: Only 24hr timepoint

Score:

8

Max. score:

10

Reversibility:

not specified

Remarks on result:

positive indication of irritation

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Reversibility:

not specified

Remarks on result:

not measured/tested

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Reversibility:

not specified

Remarks on result:

not measured/tested

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Reversibility:

not specified

Remarks on result:

not measured/tested

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Reversibility:

not specified

Remarks on result:

not measured/tested

Interpretation of results:

other: irritating

Conclusions:

Phenylethyl Alcohol is an irritant to rabbit eyes.

Executive summary:

In an eye irritation study (Carpenter et al., 1974) Phenylethyl Alcohol (undiluted) was applied to the centre of the cornea of 5 albino rabbits. The eye was examined in strong diffuse daylight 18 - 24 hours later, stained with fluorescein, and the injury scored. No vehicle was used.

Eye injury was graded according to the following 10-point scale based upon the degree of corneal necrosis that resulted. The corneal injury in rabbits was indicated as 8 out of 10. Based on the results of this study, Phenylethyl Alcohol was considered to be an eye irritant.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation/corrosion

There is one in vitro skin irritation test available and one in vitro skin corrosion test available for DMBC.

In an in vitro skin corrosion assay in a human epidermal model EPISKINTM (SM) (17/236-039B), reconstructed human epidermis tissue was exposed to 50 µLof DMBC (99.7%) for 4 hours (±10 min). Physiological saline (0.9% (w/v) NaCl solution) was used for the negative control and glacial acetic acid was used for the positive control. After removal of the test substance, tissues were washed with PBS. Three hours incubation with MTT and an overnight isopropyl alcohol extraction period followed. The OD570 of isopropyl alcohol extracts was measured on a spectrophotometer. Relative cell viability was calculated for each tissue as % of the mean viability of the negative control tissues. The colour of the test substance did not interfere with the endpoint. The test substance is not directly MTT reducing. The average viability of tissues treated by the test substance DMBC was 41.4% compared to the negative control i.e. viability was > 35%. The average viability of tissues treated by the positive control was 0.6 % of negative control average value. According to these results, the test substance is not corrosive.

In an in vitro skin irritation assay in a human epidermal model EPISKINTM (SM) (17/236-043B), reconstructed human epidermis tissue was exposed to 10 µL of DMBC (99.7%) for 15 minutes (± 0.5 min). PBS was used for the negative control and 5% SDS was used for the positive control. After removal of the test substance, tissues were post-incubated for approximately 42 hours. Three hours incubation with MTT and a 2-hour isopropyl alcohol extraction period followed. The OD570 of isopropyl alcohol extracts was measured on a spectrophotometer. Relative cell viability was calculated for each tissue as % of the mean viability of the negative control tissues. The colour of the test substance did not interfere with the endpoint. The test substance is directly MTT reducing. The average viability of tissues treated by the test substance DMBC was 66.5% compared to the negative control (after adjustment for non-specific MTT reduction) i.e. viability was > 50 %. The average viability of tissues treated by the positive control (5% SDS) was 5.3 % of negative control average value. According to these results, the test substance is not irritating.

Serious eye damage/eye irritation

There is no in vitro eye irritation test available for DMBC. There is a read-across in vivo eye irritation study in rabbits from PEA available.

In an eye irritation study (no guideline), PEA (undiluted) was applied to the centre of the cornea of 5 albino rabbits. The eye was examined in strong diffuse daylight 18 - 24 hours later, stained with fluorescein, and the injury scored. No vehicle was used. Eye injury was graded according to the following 10-point scale based upon the degree of corneal necrosis that resulted. The corneal injury in rabbits was indicated as 8 out of 10. Based on the results of this study, PEA was considered to be an eye irritant. DMBC was predicted to be an eye irritant (Eye irritation – Category 2).

The results from these studies are acceptable to use in the human health risk assessment.

Justification for classification or non-classification

Based on the available information in the dossier, the substance DMBC (CAS No. 100-86-7) is classified as Eye irritation Category 2 for serious eye damage/eye irritation based on the results of the read-across study from Phenethyl alcohol (CAS No. 60 -12 -8) and does not need to be classified for skin irritation/corrosion when considering the criteria outlined in Annex I of 1272/2008/EC.