2,2,3-trimethylcyclopent-3-enylacetonitrile

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015-06-03 to 2015-07-20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and OECD Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2013

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2,2,3-trimethylcyclopent-3-enylacetonitrile

EC Number:

239-405-4

EC Name:

2,2,3-trimethylcyclopent-3-enylacetonitrile

Cas Number:

15373-31-6

Molecular formula:

C10H15N

IUPAC Name:

2-(2,2,3-trimethylcyclopent-3-en-1-yl)acetonitrile

Test animals

Species:

human

Strain:

other: not applicable

Details on test animals or test system and environmental conditions:

Test system:
Epi-200- SIT Kit (Lot No.: 21680)
MTT-100 Assay Kit
Source: both Kits MatTek Corporation (Bratislava, Slovakia)

Test system

Controls:

yes, concurrent vehicle

Amount / concentration applied:

TEST MATERIAL
- Amount applied: The applied volume of the test item was adjusted to purity, therefore 30.8 μL instead of 30 μL (47 μL/cm2 according to guideline) of the undiluted test item was dispensed directly atop the EpiDerm™ tissue and spread to match the surface of the tissue.

Duration of treatment / exposure:

60 minutes

Observation period:

The colour of the test item/water mixture was observed during the whole incubation period (60 min). The measurement of the OD of the test item in water at 570 nm was not required and consequently not performed.

Number of animals:

Three individual tissues were used for the test item and the positive control, respectively.

Details on study design:

SCORING SYSTEM:
The mean OD of the three negative control tissues was calculated after blank correction. This value corresponds to 100 % tissue viability in the current test. For each individual tissue treated with the test item or the positive control the individual relative tissue viability is calculated according to the following formula:
Relative viability [%] = (mean OD (test item/positive control) /mean OD (negative control)) * 100
For the test item and the positive control the mean relative viability ± rel. standard deviation of the three individual tissues was calculated and used for classification according to the following prediction model:
For the current test, an irritation potential of a test item according to EU classification R38 (according to directive 67/548/EEC), H315 (according to regulation (EC) 1272/2008), and GHS category 2 according to UN GHS (published 2003, last (3rd) revision 2009) is recommended if the mean relative tissue viability of three individual tissues is reduced ≤ 50% of the negative control.

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

other: other: relative absorbance ( % of negative control)

Value:

4.7

Remarks on result:

other:

Remarks:

Basis: other: mean of 3 tissues. Time point: 60 min. Max. score: 100.0. Reversibility: other: not examined. (migrated information)

In vivo

Irritant / corrosive response data:

The mean relative absorbance after treatment with the test item was 4.7 (% of negative control). For the positive control the mean relative absorbance was found to be 6.8 (% of negative control).

Any other information on results incl. tables

Results

Dose Group	Exposure Interval	Absorbance 570 nm Tissue 1*	Absorbance 570 nm Tissue 2*	Absorbance 570 nm Tissue 3*	Mean Absorbance of 3 Tissues	Rel. Absor-bance [%] Tissue 1, 2 + 3**	Relative standard deviation [%]	Rel. Absorbance [% of Negative Control]**
Negative control	60 min	1.751	1.579	1.844	1.724	101.5 91.5 106.9	7.8	100.0
Positive control	60 min	0.129	0.115	0.109	0.118	7.5 6.7 6.3	8.6	6.8
Test item	60 min	0.111	0.073	0.062	0.082	6.5 4.2 3.6	31.8	4.7

* Mean of three replicate wells after blank correction

** relative absorbance per tissue [rounded values]: (100x(absorbance tissue))/ mean absorbance negative control

*** relative absorbance per treatment group [rounded values]: (100x(mean absorbance test item/positive control))/ mean absorbance negative control

Applicant's summary and conclusion

Interpretation of results:

irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test item was found to be irritating to skin according to UN GHS and EU CLP regulation.

Executive summary:

An in vitro study was performed to assess the irritation potential of the test item by means of the Human Skin Model Test. The test item did not reduce MTT (test for direct MTT reduction), and it did not change colour when mixed with deionised water (test for colour interference). Also its intrinsic colour was not intensive. Consequently, additional tests with freeze-killed or viable tissues were not necessary.

Each three tissues of the human skin model EpiDermTM were treated with the test item, the negative or the positive control for 60 minutes.

30.8 μL of the test item were applied to each tissue, and spread to match the surface of the tissue. 30 μL of either the negative control (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 the 60 minutes treatment interval, and thus assuring the validity of the test system.

After treatment with the test item the mean relative absorbance value decreased to 4.7 % compared to the relative absorbance value of the negative control. This value is below the threshold for irritancy of ≤ 50 %. Therefore, the test item is considered to possess an irritant potential.

In conclusion, it can be stated that in this study and under the experimental conditions reported, the substance is irritating to skin.