4-Morpholinepropanal, .alpha.,.alpha.-dimethyl-

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013-03-20 to 2013-05-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP study according to OECD/EU guideline.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

Version / remarks:

13 April 2004

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: B.40Bis: In Vitro Skin Corrosion: Human Skin Model Test

Version / remarks:

31 May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2,2-dimethyl-3-(morpholin-4-yl)propanal

EC Number:

700-569-1

Cas Number:

23588-51-4

Molecular formula:

C9H17NO2

IUPAC Name:

2,2-dimethyl-3-(morpholin-4-yl)propanal

Test material form:

other: colourless liquid

In vitro test system

Test system:

human skin model

Remarks:

EPISKIN Standard Model

Source species:

human

Vehicle:

unchanged (no vehicle)

Details on test system:

The test item was topically applied on the epidermal surface of test skin units.
The epidermis units were preincubated overnight at 37 °C in an incubator.

TEST SITE
- Area of exposure: epidermal surface of skin unit (0.38 cm2 per unit)

REMOVAL OF TEST SUBSTANCE
- Washing: PBS 1 x solution
- Time after start of exposure: 4 hours, 1 hour and 3 min after treatment, respectively.

SCORING SYSTEM: Cell viability

Control samples:

other: NaCl (9 g/L saline) and glacial acetic acid treated epidermis were used as negative and positive controls, respectively.

Amount/concentration applied:

TEST MATERIAL
- Amount applied: 50 µL of the unchanged test substance per epidermis unit

Duration of treatment / exposure:

1st Experiment: 4 hours at room temperature
2nd Experiment: 1 hour at room temperature
3rd Experiment: 3 min at room temperature

Number of replicates:

Two EPISKIN model units per experiment

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Basis: mean Two skin units. Time point: 4 hours.

Value:

31

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Basis: mean Two skin units. Time point: 1 hour.

Value:

120

Results 3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Basis: mean Two skin units. Time point: 3 minutes.

Value:

110

Any other information on results incl. tables

The test item showed significantly reduced cell viability (below 35 %) in comparison to the negative control after 4 hours exposure. No reduction of viability was observed after 1 hour and 3 minutes exposure.

Possible direct MTT reduction with test substance:

No colour change was observed after three hours of incubation. The test material did not interact with the MTT, therefore additional controls and data calculations were not necessary. A false estimation of viability can be precluded.

 

Colouring potential of test substances:

The test item showed no ability to become coloured in contact with water, therefore additional controls and data calculations were not necessary. A false estimation of viability can be precluded.

Applicant's summary and conclusion

Interpretation of results:

Category 1C (corrosive)

Conclusions:

In conclusion, in this in vitro EPISKIN model test the results indicated that the test item is corrosive to skin at 4 hours and not corrosive after 1 hour and 3 min of exposure.

Executive summary:

The purpose of this study was to determine the skin corrosion potential of the test item on reconstituted human epidermis in the EPISKIN model in vitro. The study was performed according to OECD 431 and GLP.

Disks of EPISKIN (two units / chemical / incubation time) were treated with test item and incubated for 4 hours, 1 hour and 3 min at room temperature. Exposure of test material was terminated by rinsing with PBS 1x solution. The viability of each disk was assessed by incubating the tissues for 3 hours with MTT solution at 37 °C in 5 % CO2 protected from light. The formazan precipitated was then extracted using acidified isopropanol and quantified spectrophotometrically. NaCl (9 g/L saline) and glacial acetic acid treated epidermis were used as negative and positive controls respectively. For each treated tissue, viability was expressed as a % relative to negative control. The test item is considered to be non-corrosive to skin, if the mean relative viability after 4 hours of exposure is above or equal 35 % of the negative control.

The test item showed significantly reduced cell viability (below 35 %) in comparison to the negative control after 4 hours exposure. No reduction of viability was observed after 1 hour and 3 minutes exposure. The mean test item treated tissue viabilities were 31 % at 4 hours, 120 % at 1 hour and 110 % at 3 minutes of exposure. Positive and negative controls showed the expected cell viability values within acceptable limits. The experiment was considered to be valid.

In this in vitro EPISKIN model test the results indicated that the test item was corrosive to skin at 4 hours and not corrosive after 1 hour and 3 min of exposure. Based on the results above the test item is classified as Corrosive 1C (EU) 1272/2008 CLP.