1-hydroxyoctan-2-one

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15-19 January 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

This is a Klimisch 1 OECD 439 guideline study conducted on the registered substance 1-hydroxyoctan-2-one in accordance GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1-hydroxyoctan-2-one

Cas Number:

7019-19-4

Molecular formula:

C8H16O2

IUPAC Name:

1-hydroxyoctan-2-one

Test material form:

liquid

Details on test material:

Batch 1203/16/100

Specific details on test material used for the study:

Batch 1081-67E

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Justification for test system used:

Initially the predictive capacity of the modified EpiDerm'M Skin Irrit ation Test (SIT) test method, using MatTek EpiDerm™ tissue model EPI-200, underwent full prospective validation from 2003-2007. The test method components of this method were used to define the essential test methods components of the original and updated ECVAM Performance Standards (PS).

A modification of the original EpiDerm'M SIT was validated using the original ECVAM PS in 2008. In 2008, ESAC concluded that the Modified EpiDerm'M SIT has sufficient accuracy and reliability for prediction of R38 skin irritating and no-label (non-skin irritating) test substances.

Vehicle:

unchanged (no vehicle)

Details on test system:

The reconstructed human epidermal model EpiDermTM (EPI-200-MatTek Corporation) consists of normal human-derived epidermal keratinocytes which have been cultured to form a multi-layered highly differentiated model of the human epidermis. It consists of organised basal, spinous and granular layers and a multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous to those found in vivo.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

A single topical application of 30 µl of neat test item, negative control (DPBS) or positive control (SDS 5%) was applied to the surface of EpiDerm™ model

Duration of treatment / exposure:

60 ± 1 minute (25 minutes at room temperature and 35 minutes at 37"C, 5% C02, ≥95% RH)

Duration of post-treatment incubation (if applicable):

42 ± 4h post-treatment incubation, prior to the MTT endpoint

Number of replicates:

Three tissues per condition (Negative Control, Positive Control and Test Item)

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Remarks:

Corrected for freeze killed control tissues

Run / experiment:

1

Value:

4.834

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Results 2

Irritation / corrosion parameter:

% tissue viability

Remarks:

Uncorrected for freeze killed control tissue

Run / experiment:

1

Value:

8.946

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Other effects / acceptance of results:

The viability of the MTT Interference Control (Freeze Killed Tissues) was 4.112%. Therefore, this value was subtracted from the uncorrected result of 8.946 %viability to yield the corrected result of 4.834% viability.

Any other information on results incl. tables

Viability measurements after 60 min (± 1min) of application and 42h (± 4h) post-incubation of test and reference items and controls.

Condition	Tissue #	Raw data		Blank corrected data		Mean OD	% of Viability
		Aliquot 1	Aliquot 2	Aliquot 1	Aliquot 2
NC	Tissue 1	1.767	1.749	1.611	1.593	1.602	106.681
	Tissue 2	1.556	1.55	1.400	1.394	1.397	93.030
	Tissue 3	1.662	1.662	1.506	1.506	1.506	100.289
PC	Tissue 1	0.258	0.238	0.102	0.082	0.092	6.127
	Tissue 2	0.21	0.217	0.054	0.061	0.058	3.829
	Tissue 3	0.2	0.209	0.044	0.053	0.049	3.230
TA1	Tissue 1	0.274	0.264	0.118	0.108	0.113	7.525
	Tissue 2	0.311	0.31	0.155	0.154	0.155	10.289
	Tissue 3	0.291	0.292	0.135	0.136	0.136	9.023

NC: negative control (DPBS), PC: Positive control (SDS 5%), TA1: Test Item

Mean and SD of cell viability measurements and of viability percentages after 60 min (± 1min) of application and 42h (± 4h) post-incubation.

Name	Code	Mean of OD	SD of OD	Mean of viability (%)	SD of viability (%)	CV %	Classification
DPBS	NC	1.502	0.103	100.000	6.830	6.830	Non-Irritant
SDS 5%	PC	0.066	0.023	4.395	1.529	34.791	Irritant
EXPINN PC17032	TA1	0.134	0.021	8.946	1.383	15.465	Irritant

NC: Negative control (DPBS), PC: Positive control (SDS 5%), TA1: Test Item.

Prediction model of irritancy: test items that reduce the viability to 50% or below are irritant (I), test items with a percentage viability above 50% are considered to be non-irritant (NI).

Mean % viabilities obtained from additional tests to correct for MTT interference.

Test Item	MTT Interference Control (FK): % viability	Initial % Viability	Corrected % Viability
TA1	4.112	8.946	4.834

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

The percentage of viability obtained with the test item was 4.834%, therefore it was considered as Irritant to the skin.

Executive summary:

In vitro assessment of the skin irritation potential of 1 -hydroxyoctan-2 -one was performed according to OECD guideline TG439:In vitroSkin Irritation: Reconstructed Human Epidermis (RHE) Test Method.This in vitro assay predicts the skin irritation potential of a chemical by measurement of its cytotoxic effect on the EpiDerm™ tissue model.The test item is applied directly to the skin surface, providing a good model of “real life” exposure. Cell viability is measured by enzymatic conversion of the vital dye MTT into a blue formazan salt that is quantitatively measured after extraction from the skin tissues. Irritant test items are identified by their ability to decrease cell viability below defined threshold levels (below or equal to 50% for UN GHS Category 2). If the viability is greater than 50%, the test item is classified as Non-Irritant (no-label).

Prior to the execution of the study, the required compatibility checks confirmed that the test item interfered with MTT. Therefore, additional freeze killed tissues were included in order to determine if any direct reduction of MTT had taken place during the main study. No water colouration was observed.

The percentage of viability obtained with the test item 1 -hydroxyoctan-2 –one was 4.834%, therefore it was considered as Irritating to the skin.