Registration Dossier

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:
2016
Report date:
2016

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)
Deviations:
no
Principles of method if other than guideline:
The test is performed according to OECD criteria.
GLP compliance:
yes (incl. QA statement)
Remarks:
Hessisches Minesterium für Umwelt, Klimatschutz, Landwirtschaft und Verbraucherschutz

Test material

Constituent 1
Chemical structure
Reference substance name:
4-(4-methoxyphenyl)butan-2-one
EC Number:
203-184-2
EC Name:
4-(4-methoxyphenyl)butan-2-one
Cas Number:
104-20-1
Molecular formula:
C11H14O2
IUPAC Name:
4-(4-methoxyphenyl)butan-2-one

Test animals

Species:
human
Strain:
other: human reconstructed epidermis model
Details on test animals or test system and environmental conditions:
Epi-200 SIT kits and MTT-100 assays diluent from MatTek Corporation (82105 Bratislava, Slovakia).
EpiDerm tissue consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multilayered, highly differentiated model of human epidermis

Test system

Type of coverage:
other: in vitro test
Preparation of test site:
other: in vitro test
Vehicle:
unchanged (no vehicle)
Controls:
other: Negative control: 30µL DPBS (MatTek) ; Positive control: 30µL of a 5% SLS (Sodium Lauryl Sulphate) solution in deiosined water (MatTek)
Duration of treatment / exposure:
60 minutes

Results and discussion

In vitro

Results
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
Mean
Value:
96.5
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no indication of irritation

Any other information on results incl. tables

Results:

Dose Treatment Interval Absorbance 570 nm Tissue 1* Absorbance 570 nm Tissue 2* Absorbance 570 nm Tissue 3* Mean Absorbance of 3 Tissues Rel. Absorbance (%) Tissue 1, 2, 3 ** Relative Standard Deviation Mean Rel. Absorbance (% of negative control)***
Negative Control 60 min 1.705 1.552 1.747 1.668 102.2 6.1 100.0
93.1
104.7
Positive Control 60 min 0.075 0.083 0.085 0.081 4.5 6.4 4.9
5.0
5.1
Test item 60 min 1.537 1.663 1.630 1.610 92.2 4.0 96.5
99.7
97.7

* Mean of three replicate wells after blank correction

** Relative absorbance per tissues (rounded value): (100*absorbance of tissue)/ (mean absorvbance negative control)

*** Relative absorbance per treatment group (rounded values): (100* mean absorbance (test item/positive control))/(mean absorbance negative control).

The mean relative absorbance value of the test item, corresponding to the cell viability, decreased to 96.5% (threshold for irritacy ≤ 50%), consequently the test item was not irritant to skin.

Applicant's summary and conclusion

Interpretation of results:
not irritating
Conclusions:
In conclusion, it can be stated that in this study and under the experimental conditions reported the test substance is not irritant to skin to UN GHS and EU CLP regulation.
Executive summary:

The study has been performed according to OECD 439 guideline. This in vitro study was performed to assess the irritation properties of the test substance. by means of the Human Skin Model test.

The test item did not reduce MTT and it did not change colour when mixed with deionised water. Consequently, additional tests with freeze-killed or viable tissues were not necessary.

Each three tissues of the human skin model EpiDerm were treated with the test item, the negative control and the positive control for 60 minutes. 30 µL of the test substance were applied to each tissues, and spread to match the surface of the tissues. 30 µL of either the negative (DPBS) or the positive control (5% SLS) were applied to each tissue.

After treatment with the negative control the absorbance values were well in the required range of the acceptability criterion of mean OD ≥ 0.8 and ≤ 2.8 for the 60 minutes treatment interval, thus assuring the quality of the tissues.

Treatment with the positive control induced a sufficient decrease in the relative absorbance as compared to the negative control for 60 minutes treatment interval, and thus assuring the validity of the test system.

After the treatment with the test substance, the mean relative absorbance value decreased irrelevantly to 96.5% compared to the relative absorbance value of the negative control. This value is above the threshold for irritancy of ≤ 50%.

Therefore, the test item is not considered to possess an irritant potential.

In conclusion, it can be stated that in this study and under the experimental conditions reported the test substance is not irritant to skin to UN GHS and EU CLP regulation