m-phenylene di(acetate)

Endpoint summary

Description of key information

A valid in vivo assay in rabbits and an in vitro assay using a human skin model is available. Both tests were negative (not irritating).

In the in vivo eye irritation assay on rabbits the test item (resorcinol diacetate) was irritating. The effects were reversible within 7 days.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

500 mg Cohedur RK (= m-phenylene di(acetate)) were semiocclusively applied once to the intact skin (ear) of two young adult New Zealand white rabbits (3.0–4.0 kg) for an exposure period of 24 hours. Evaluation of skin irritation was made until day 7 according to Draize.

GLP compliance:

no

Species:

rabbit

Strain:

New Zealand White

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

water

Controls:

not required

Amount / concentration applied:

500 mg

Duration of treatment / exposure:

24 hours.

Observation period:

7 days

Number of animals:

2 animals

Details on study design:

After 24 hours the test material was removed with water and soap.

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: score = 0 at any time point

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: score = 0 at any time point

Irritant / corrosive response data:

Erythema and edema score = 0 at 24/48/72 hours.

Cohedur RK (= m-phenylene di(acetate)) was not irritating under the condition of the test (Erythema and edema score = 0 at 24/48/72 hours).

Interpretation of results:

GHS criteria not met

Conclusions:

Cohedur RK (= m-phenylene di(acetate)) was not irritating under the condition of the test (Erythema and edema score = 0 at 24/48/72 hours).

Executive summary:

500 mg Cohedur RK (= m-phenylene di(acetate)) were semiocclusively applied once to the intact skin (ear) of two young adult New Zealand white rabbits (3.0–4.0 kg) for an exposure period of 24 hours. Evaluation of skin irritation was made until day 7 according to Draize. Erythema and edema score was 0 at 24/48/72 hours.

Reference 2

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

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)

Principles of method if other than guideline:

The ability of Resorcinol diacetate to induce skin irritation on a human three dimensional epidermal model (EPISKIN Small Model (EPISKIN-SMTM)) was examined. The possible skin irritation potential of the test item was tested through topical application for 15 minutes.

GLP compliance:

yes

Specific details on test material used for the study:

Identification. Resorcinol diacetate
Appearance: Brown liquid
Purity/Composition: 98.52% (GC)
Test item storage: At room temperature
Purity/composition correction factor: No correction factor required
Chemical name (IUPAC), synonym 1,3-Diacetoxybenzene
or trade name
CAS Number: 108-58-7
Molecular formula: C10H10O4
Molecular weight: 194.18

Test system:

human skin model

Source species:

other: not applicable - human skin model

Cell type:

other: The model is a three-dimensional human epidermis model, which consists of adult humanderived epidermal keratinocytes.

Cell source:

other: SkinEthic Laboratories, Lyon, France.

Source strain:

other: SkinEthic Laboratories, Lyon, France.

Details on animal used as source of test system:

not applicable - human skin model

Justification for test system used:

In the interest of sound science and animal welfare, a sequential testing strategy is recommended to minimise the need of in vivo testing. One of the validated in vitro skin irritation tests is the EPISKIN test, which is recommended in international guidelines (e.g. OECD and EC).

Details on test system:

This model is a three-dimensional human epidermis model, which consists of adult humanderived epidermal keratinocytes which have been seeded on a dermal substitute consisting of a collagen type I matrix coated with type IV collagen. The keratinocytes were cultured for 13 days, which results in a highly differentiated and stratified epidermis model comprising the main basal, supra basal, spinous and granular layers and a functional stratum corneum.

Control samples:

other: yes, negative and positive controls.

Amount/concentration applied:

Twenty five μl of the undiluted test item was added into 12-well plates on top of the skin tissues. Three tissues were treated with 25 μl PBS (negative control) and 3 tissues with 25 μl 5% SDS (positive control) respectively.

Duration of treatment / exposure:

After the exposure period of 15 ± 0.5 minutes at room temperature, the tissues were washed with phosphate buffered saline to remove residual test item. After rinsing, the cell culture inserts were each dried carefully and moved to a new well on 2 ml pre-warmed maintenance medium until all tissues were dosed and rinsed. Subsequently the skin tissues were incubated for 42 hours at 37°C.

Duration of post-treatment incubation (if applicable):

Subsequently the skin tissues were incubated for 42 hours at 37°C.

Number of replicates:

Three identically treated replicates.

Species:

other: not applicable - human skin model

Strain:

other: not applicable - human skin model

Details on test animals or test system and environmental conditions:

not applicable - human skin model

Type of coverage:

other: not applicable - human skin model

Preparation of test site:

other: not applicable - human skin model

Vehicle:

other: not applicable - human skin model

Amount / concentration applied:

not applicable - human skin model

Duration of treatment / exposure:

not applicable - human skin model

Observation period:

not applicable - human skin model

Number of animals:

not applicable - human skin model

Details on study design:

not applicable - human skin model

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Resorcinol diacetate

Value:

112

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

other: mean tissue viability (percentage of control)

Run / experiment:

Negative control

Value:

100

Remarks on result:

other: control

Irritation / corrosion parameter:

other: mean tissue viability (percentage of control)

Run / experiment:

Positive control

Value:

23

Remarks on result:

other: control

Other effects / acceptance of results:

Acceptability of the assay:
The in vitro skin irritation test is considered acceptable if it meets the following criteria:
a) The absolute mean OD570 (optical density at 570 nm) of the three tissues of the negative control should reasonably be within the laboratory historical control data range and the Standard Deviation value of the % viability should be < 18.
b) The mean relative tissue viability of the positive control should be < 50% relative to the negative control and the Standard Deviation value (SD) of the % viability should be < 18.
c) The Standard Deviation value calculated from individual % tissue viabilities of the three identically treated replicates should be < 18.

Interpretation of results:

other: Resorcinol diacetate is non-irritant in the in vitro skin irritation test under the experimental conditions described in this report.

Conclusions:

Resorcinol diacetate is non-irritant in the in vitro skin irritation test under the experimental conditions described in this report.

Executive summary:

The ability of Resorcinol diacetate to induce skin irritation on a human three dimensional epidermal model (EPISKIN Small Model (EPISKIN-SMTM)) was examined. The possible skin irritation potential of the test item was tested through topical application for 15 minutes.

The study procedures described in this report were based on the most recent OECD and EC guidelines.

Resorcinol diacetat (test item was a brown liquid with a purity of 98.52%) was applied undiluted (25µl) directly on top of the skin tissues for 15 ± 0.5 minutes.

After a 42 hour post-incubation period, determination of the cytotoxic (irritancy) effect was performed. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT at the end of the treatment.

Skin irritation is expressed as the remaining cell viability after exposure to the test item. The relative mean tissue viability obtained after 15 ± 0.5 minutes treatment with the test item compared to the negative control tissues was 112%. Since the mean relative tissue viability for the test item was above 50% after 15 ± 0.5 minutes treatment the test item is considered to be non-irritant.

The positive control had a mean cell viability of 23% after 15 ± 0.5 minutes exposure. The absolute mean OD570 (optical density at 570 nm) of the negative control tissues was within the laboratory historical control data range. The standard deviation value of the percentage viability of three tissues treated identically was less than 13%, indicating that the test system functioned properly.

Finally, it is concluded that this test is valid and that Resorcinol diacetate is non-irritant in the in vitro skin irritation test under the experimental conditions described in this report.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

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:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

A dose of 50 mg Chohedur RK (= m-phenylene di(acetate)) was administered into one eye of two young adult New Zealand white rabbits (3–4 kg). The eyes were examined and the grade of ocular reaction was recorded until day 7 post administration according to Draize.

GLP compliance:

no

Species:

rabbit

Strain:

New Zealand White

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

50 mg

Duration of treatment / exposure:

7 days

Observation period (in vivo):

7 days

Duration of post- treatment incubation (in vitro):

None

Number of animals or in vitro replicates:

2 animals

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

2.66

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0.83

Max. score:

2

Reversibility:

fully reversible within: 7 days

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Score:

2.33

Max. score:

3

Reversibility:

fully reversible within: 7 days

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

1.33

Max. score:

4

Reversibility:

fully reversible within: 7 days

Irritant / corrosive response data:

All effects were fully reversible within 7 days.

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

Based on the Draize scores for cornea opacity and conjunctivae a classification as eye irritant is adequate.

Executive summary:

A dose of 50 mg Chohedur RK (= m-phenylene di(acetate)) was administered into one eye of two young adult New Zealand white rabbits (3–4 kg). The eyes were examined and the grade of ocular reaction was recorded until day 7 post administration according to Draize. The cornea score was 2.66, the iris score was 0.83 and the conjunctivae and chemosis score were 2.33 and 1.33, respectively. All effects were reversible within 7 days. According to CLP classification criteria (Regulation (EC) No 1272/2008) a classification as Eye Irrit. 2 ( H319: Causes serious eye irritation.) is justified.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Skin irritation:

500 mg Cohedur RK (= m-phenylene di(acetate)) were semiocclusively applied once to the intact skin (ear) of two young adult New Zealand white rabbits (3.0–4.0 kg) for an exposure period of 24 hours. Evaluation of skin irritation was made until day 7 according to Draize. Erythema and edema score was 0 at 24/48/72 hours.

In an additional in vitro skin irritation test using a human skin model, Resorcinol diacetate was non-irritant.

According to CLP classification criteria (Regulation (EC) No 1272/2008) a classification is not justified.

Eye irritation:

A dose of 50 mg Chohedur RK (= m-phenylene di(acetate)) was administered into one eye of two young adult New Zealand white rabbits (3–4 kg). The eyes were examined and the grade of ocular reaction was recorded until day 7 post administration according to Draize. The cornea score was 2.66, the iris score was 0.83 and the conjunctivae and chemosis score were 2.33 and 1.33, respectively. All effects were reversible within 7 days. According to CLP classification criteria (Regulation (EC) No 1272/2008) a classification as Eye Irrit. 2 ( H319: Causes serious eye irritation.) is justified.