Dichlorotricyclo[8.2.2.24,7]hexadeca-1(12),4,6,10,13,15-hexaene, mixed isomers

Endpoint summary

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:

2016

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)

Deviations:

no

GLP compliance:

yes

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Control samples:

yes, concurrent no treatment

yes, concurrent positive control

Amount/concentration applied:

20 mg of test item/0.5 cm2

Duration of treatment / exposure:

3 minutes and 60 minutes

Number of replicates:

Three replicates were used for both the exposure times

Irritation / corrosion parameter:

% tissue viability

Value:

106

Negative controls validity:

valid

Positive controls validity:

valid

Irritation / corrosion parameter:

% tissue viability

Value:

90

Negative controls validity:

valid

Positive controls validity:

valid

Interpretation of results:

other: non-corrosive

Conclusions:

From the results of this study, under the specified experimental conditions, DPX-C (Di-Cloro-Di-p-Xililene) is concluded to be non-corrosive in in vitro skin corrosion test using reconstructed human epidermis (RHE) tissues.

Executive summary:

This study was performed to evaluate the non-corrosive and corrosive potential of DPX-C (Di-Cloro-Di-p-Xililene) using reconstructed human epidermis (RHE) tissue in accordance with the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS).

The tissues were exposed to DPX-C (Di-Cloro-Di-p-Xililene) for 3 minutes and 60 minutes at room temperature using three replicates/time point and positive control tissues were exposed for 60 minutes. Two tissue replicates were used for adapted negative control and positive controls (8N KOH) was exposed for 60 minutes, for the treatment of freeze killed tissues (to correct nonspecific MTT reduction). All the treated tissues were incubated at room temperature.

Percent relative viability in the tissues treated with the test item was 106% at 3 minute exposure period and 90% at 60 minute exposure period. Significant reduction in percent cell viability was not observed at any of the exposure period in the treated tissues when compared with the concurrent negative control. Differences between the viability of treated tissues was around 2% i.e. %CV.

All the OD values for the negative control replicates were between 2.292 to 2.591, against guideline requirement of ≥ 0.8 and ≤ 3.0 (the acceptance criteria for SkinEthicTM RHE model). Positive control showed 0.54% cell viability, against guideline requirement of <15%, compared to concurrent negative control, which demonstrate the efficiency of the test system, SkinEthicTM RHE model.

All criteria for a valid study were met as described in the study plan. From the results of this study, under the specified experimental conditions, DPX-C (Di-Cloro-Di-p-Xililene) is concluded to be non-corrosive in in vitro skin corrosion test using reconstructed human epidermis (RHE) tissues.

Reference 2

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016

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)

Deviations:

no

GLP compliance:

yes

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

16 mg/0.5 cm2 of test item, 16 µL/0.5 cm2 sterile dulbecco’s phosphate buffered saline (DPBS) and 16 µL/0.5 cm2 of 5% sodium dodecyl sulphate (5% aq.) were applied

Duration of treatment / exposure:

42 ± 1 minutes

Number of replicates:

Three replicates were used for test item, positive control and negative control

Irritation / corrosion parameter:

% tissue viability

Value:

98.209

Negative controls validity:

valid

Positive controls validity:

valid

Interpretation of results:

other: No Category

Conclusions:

Based on the results of this study, an indication of the classification for DPX-C (Di-Cloro-Di-p-Xililene) is as follows:
Globally Harmonized System of Classification and Labelling of Chemicals: No Category.

Executive summary:

This study was performed to evaluate the non-irritant and irritant potential of DPX-C (Di-Cloro-Di-p-Xililene) using reconstructed human epidermis (RHE) tissue in accordance with the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS). The method was followed as per the guideline of the OECD 439 (July 2015).

The tissues were exposed to negative control (Dulbecco’s Phosphate Buffered Saline (DPBS)), positive control (sodium dodecyl sulfate 5% aqueous (SDS)) and DPX-C (Di-Cloro-Di-p-Xililene) in triplicate for 42±1 minutes at room temperature.

Mean cell viability in the tissues treated with the test item was 98.209% at 42 minutes exposure period. Significant reduction in percent cell viability was not observed in the treated tissues when compared with the concurrent negative control.

Optical density values for the negative control replicates were between 1.958 to 2.025, against guideline requirement of ≥0.8 and ≤3.0 (≥ 1.2 as per SkinEthic SOP), blank was between 0.042 to 0.046 which met the guideline requirement i.e. OD< 0.1. Positive control showed a 1.457% cell viability, against the acceptance criteria of <40% for SkinEthic RHE model, compared to concurrent negative control. Variation between the tissue replicates i.e. CV% value was between 0.522 for test item group, 3.500 for positive control and 1.155 for negative control against guideline requirement of ≤ 18%, which demonstrate the efficiency of the test system, SkinEthicTM RHE model. All criteria for a valid study were met as described in the study plan.

Based on the results of this study, an indication of the classification forDPX-C (Di-Cloro-Di-p-Xililene) is as follows:

Globally Harmonized System of Classification and Labelling of Chemicals: No Category

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016

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 i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage)

Deviations:

no

GLP compliance:

yes

Species:

cattle

Vehicle:

other: corn oil

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

One set of corneas were treated with 750 mg (pulverized) of test item (as such). One set of corneas were treated with 750 μL of the prepared test item [20% (w/v) concentration in corn oil]

Duration of treatment / exposure:

4 h ± 5 minutes

Irritation parameter:

in vitro irritation score

Run / experiment:

corneas treated with 750 mg DPX-C (Di-Cloro-Di-p-Xililene)

Value:

0.42

Negative controls validity:

valid

Positive controls validity:

valid

Irritation parameter:

in vitro irritation score

Run / experiment:

corneas treated with 750 mg DPX-C (Di-Cloro-Di-p-Xililene) (suspension) at 20% (w/v)

Value:

0.57

Negative controls validity:

valid

Positive controls validity:

valid

Interpretation of results:

other: No Category

Conclusions:

Based on the results of this study, an indication of the classification for DPX-C (Di-Cloro-Di-p-Xililene) is as follows:
Classification (OECD 437): No Category.

Executive summary:

This study was conducted to evaluate theocular irritancy of a DPX-C (Di-Cloro-Di-p-Xililene)in compliance with the OECD test guideline forBCOP Test.

InBCOP test, five sets each consisting of three corneas were tested.First set served as vehicle control and was treated with 750 μL normal saline. The second set was treated with 750 mgDPX-C (Di-Cloro-Di-p-Xililene) (pulverized and was applied to the surface of cornea as such)while the third set served aspositive control and was treated with750 μL20% (w/v) imidazole innormal saline. In addition to this one set was treated with corn oil and one set was treated with 750 μLDPX-C (Di-Cloro-Di-p-Xililene) (suspension) at 20% (w/v) concentration in corn oil.Post application the corneas were incubated for approximately 4 h at32 ºC.At the end of the incubation period reading for opacity were taken.

Post opacity reading permeability was measured by applying1 mL of fluorescein sodium solution (5 mg/mL)on to the anterior surface of the cornea and was incubated forapproximately90 min at32 ºC. At the end of the incubation period OD was measured at 490 nm for the fluid collected from the posterior chamber.

The meanIn-VitroIrritatancy Score(IVIS) ofnormal saline (vehicle control), corn oiland750 μL20% (w/v) imidazole innormal saline(positive control)treated corneaswere found to be -0.95, 0.62 and 69.49,respectively,which confirmed the reliability of the test procedure. The IVIS score for the corneas treated with 750 mgDPX-C (Di-Cloro-Di-p-Xililene) and750 μLDPX-C (Di-Cloro-Di-p-Xililene) (suspension) at 20% (w/v) concentration in corn oil were found to be0.42 and 0.57, respectively.

Based on the results of this study, an indication of the classification forDPX-C (Di-Cloro-Di-p-Xililene)is as follows:

Classification (OECD 437): No Category.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

According to the test performed and to the Regulation (EC) n. 1272/2008, Dichloro-p-cyclophane is not classified as irritating to the skin and to the eye.