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Administrative data

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

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)
Deviations:
no
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
1,10-dichlorodecane
EC Number:
218-489-6
EC Name:
1,10-dichlorodecane
Cas Number:
2162-98-3
Molecular formula:
C10H20Cl2
IUPAC Name:
1,10-dichlorodecane
Test material form:
liquid

In vitro test system

Test system:
human skin model
Source species:
human
Cell type:
other: normal human epidermal keratinocytes (NHEK)
Justification for test system used:
This test uses the EpiDerm™ reconstructed human epidermis model (MatTek) which consists of normal human epidermal keratinocytes (NHEK) and therefore represents in vitro the target organ of the species of interest and closely mimics the biochemical and physiological properties of the upper parts of the human skin, i.e. the epidermis.
Vehicle:
unchanged (no vehicle)
Details on test system:
Prior to treatment, all EpiDerm™ tissues were gently blotted to remove moisture. The test item was applied undiluted. 30 µL (47 µL/cm2) of the test item were dispensed directly atop the EpiDerm tissue. The test item was gently spread to match size of the tissue using a bulb-headed Pasteur pipette.
Control samples:
yes, concurrent negative control
yes, concurrent positive control
Amount/concentration applied:
1. Negative control 30 µL DPBS
2. Positive control 30 µL 5% SDS solution
3. Test Item 30 µL (undiluted)
The test was performed on a total of 3 tissues per dose group
Duration of treatment / exposure:
60 ± 1 min incubation time
Duration of post-treatment incubation (if applicable):
18 ± 2 h
Number of replicates:
3

Results and discussion

In vitro

Results
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
Mean
Value:
ca. 95.9
Vehicle controls validity:
not examined
Negative controls validity:
valid
Positive controls validity:
valid

Any other information on results incl. tables

Name

Negative Control

Positive Control

Test Item

Tissue

1

2

3

1

2

3

1

2

3

Absolute OD570

1.956

1.874

1.856

0.096

0.102

0.099

1.652

1.930

1.876

1.969

1.899

1.889

0.097

0.103

0.102

1.670

1.988

1.870

OD570(Blank Corrected)

1.913

1.832

1.814

0.053

0.059

0.057

1.609

1.887

1.834

1.926

1.856

1.846

0.055

0.061

0.059

1.627

1.945

1.827

Mean OD570of the Duplicates (Blank Corrected)

1.920

1.844

1.830

0.054

0.060

0.058

1.618

1.916

1.830

Total Mean OD570of 3 Replicate Tissues (Blank Corrected)

1.865*

0.057

1.788

SD OD570

0.048

0.003

0.153

Relative Tissue Viability [%]

103.0

98.9

98.1

2.9

3.2

3.1

86.8

102.8

98.2

Mean Relative Tissue Viability [%]

100.0

3.1**

95.9

SD Tissue Viability [%]***

2.6

0.2

8.2

CV [% Viabilities]

2.6

5.4

8.6

The potential of the test item to induce skin irritation was analysed by using the three-dimensional humanepidermismodel EpiDermä(MatTek) comprising a reconstructed epidermis with a functionalstratum corneum.

In the present study 1,10-Dichlorodecane was applied topically to the EpiDermätissue for 60 min followed by a 42 h post-incubation period and immediate determination of cytotoxic effects via MTT reduction assay.

Irritant potential of the test item was predicted from the relative mean tissue viabilities obtained compared to the corresponding negative control tissues concurrently treated with DPBS.

The mixture of 30 µL test item per 1 mL MTT medium showed no reduction of MTT compared to the solvent. The mixture did not turn blue/purple. Therefore, NSMTT equalled 0%.

The mixture of 30 µL of the test item per 300 µl aqua dest. and/or per 300 µL isopropanol showed no colouring detectable by unaided eye-assessment. Therefore, NSC equalled 0%.

The test item showed no irritant effects. The mean relative tissue viability (% negative control) was > 50% (95.9%) after 60 min treatment and 42 h post-incubation.

The controls confirmed the validity of the study. The mean absolute OD570 of the three negative control tissues was 0.8 and ≤ 2.8. The mean relative tissue viability (% negative control) of the positive control was  20% (3.1%). Standard deviation of viability of replicate tissues of all dose groups was ≤ 18% (0.2 - 8.2%).

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
In this study under the given conditions the test item showed no irritant effects. The relative mean tissue viability after 60 min of exposure and 42 h post-incubation was > 50%. The test item is therefore classified as “non-irritant” in accordance with UN GHS “No Category”.

Executive summary:

1.1.       Summary Results

In the present study the skin irritant potential of 1,10-Dichlorodecane was analysed.The EpiDerm™-Standard Model (EPI-200™), a reconstituted three-dimensional human epidermis model, was used as a replacement for the Draize Skin Irritation Test (OECD TG 404) to distinguish between UN GHS “Category 2” skin irritating test substances and not categorized test substances (“No Category”) which may be considered as non-irritant. Hereby, the test item was applied topically. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT after a 60 min exposure and 42 h post-incubation periodand compared to those of the concurrent negative controls. The mixture of 30 µL test item per 1 mL MTT medium showed no reduction of MTT compared to the solvent. The mixture did not turn blue/purple. Therefore, NSMTT equalled 0%. The mixture of 30 µL of the test item per 300 µl aqua dest. and/or per 300 µL isopropanol showed no colouring detectable by unaided eye-assessment. Therefore, NSC equalled 0%. The test item showed no irritant effects. The mean relative tissue viability (% negative control) was > 50% (95.9%) after 60 min treatment and 42 h post-incubation.