L-arabinose

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June 30, 2017 - August 31, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

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:

28 July 2015

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

06 July 2012

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: EpiSkin™ SOP, Version 1.8

Version / remarks:

February 2009

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Toxi-Coop ZRT. 8230 Balatonfüred, Arácsi út 97. (1045 Budapest, Berlini út 47-49). Hungary

Test material

Test material information

Constituent 1

Reference substance name:

L-arabinose

EC Number:

226-214-6

EC Name:

L-arabinose

Cas Number:

5328-37-0

Molecular formula:

C5H10O5

IUPAC Name:

L-arabinose

Test material form:

solid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Batch No. of test material: AD16081001
- Expiration date of the batch: 09 August 2019

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room Temperature
- Stability under test conditions: stable under ambient conditions

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: adult donors

Justification for test system used:

The EPISKIN model has been validated for irritation testing in an international trial. After a review of scientific reports and peer reviewed publications on the EPISKIN method, it showed evidence of being a reliable and relevant stand-alone test for predicting rabbit skin irritation, when the endpoint is evaluated by MTT reduction and for being used as a replacement for the Draize Skin Irritation test (OECD TG 404 and Method B.4 of Annex V to Directive 67/548/EEC) for the purposes of distinguishing between skin irritating and no skin irritating test substances (STATEMENT OF VALIDITY OF IN-VITRO TESTS FOR SKIN IRRITATION; ECVAM; Institute for Health & Consumer Protection; Joint Research Centre; European Commission; Ispra; 27 April 2007).

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiSkin(TM)SM, EPISKIN SNC Lyon, France, is a three-dimensional human epidermis model
- Tissue batch number(s): 17-EKIN-030
- Expiry date: July 31, 2017

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: room temperature
- Temperature of post-treatment incubation: 37°C

REMOVAL OF TEST MATERIAL AND CONTROLS
- Volume and number of washing steps: approximately 25 mL PBS 1 x solution; rest of the PBS was removed from epidermal surface with a suitable pipette tip
linked to a vacuum source (care was taken to avoid damaging to the epidermis)
- Observable damage in the tissue due to washing: none

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 3 mg/mL stock solution; 2 mL of 0.3 mg/mL per well
- Incubation time: 3 hours
- Spectrophotometer: Thermo Scientific; Multiscan FC
- Wavelength: 570 nm

NUMBER OF REPLICATE TISSUES: 3

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 1

PREDICTION MODEL / DECISION CRITERIA
- The test substance is considered to be irritant to skin if the viability after 15 minutes exposure and 42 hours post incubation is less than or equal to 50 % of the negative control.
- The test substance is considered to be non-irritant to skin if the viability after 15 minutes exposure and 42 hours post incubation is greater than 50 % of the negative control.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount applied: 10 mg

NEGATIVE CONTROL
- Amount applied: 10 µL

POSITIVE CONTROL
- Amount applied: 10 µL
- Concentration: 5 %

Duration of treatment / exposure:

15 min

Duration of post-treatment incubation (if applicable):

42 hours

Number of replicates:

3

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Value:

93

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

- OTHER EFFECTS:
- Visible damage on test system: No
- Direct-MTT reduction: No
- Colour interference with MTT: No

DEMONSTRATION OF TECHNICAL PROFICIENCY: Prior to routine use of the method Toxi-Coop ZRT. demonstrated the technical proficiency in a separate study (study no.: 392.554.2938) using the ten Proficiency Chemicals according to OECD Test Guideline No. 439.

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: Yes
- Acceptance criteria met for positive control: Yes
- Acceptance criteria met for variability between replicate measurements: Yes

Any other information on results incl. tables

Validity of the test:

The mean OD value of the three negative control tissues was 0.795. The mean OD value obtained for the positive control was 0.162 and this result corresponds to 20 % viability when compared to the results obtained from the negative controls. Each calculated standard deviation value (SD) for the % viability was below 18. All validity criteria were within acceptable limits and therefore the study can be considered as valid.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In an in vitro skin irritation assay according to OECD Guideline 439, the test substance did not show skin irritating properties.

Executive summary:

In an in vitro skin irritation assay according to OECD Guideline 439, the skin irritating potential of L-Arabinose was determined on reconstituted human epidermis in the EPISKIN model. Disks of epidermal units (three units) were treated with the test item and incubated for 15 minutes at room temperature. Exposure of the test material was terminated by rinsing the epidermal units with 1x PBS solution. Epidermis units were then incubated at 37 °C for 42 hours in an incubator with 5 % CO2. The viability of each disk was assessed by incubating the tissues for 3 hours with MTT solution at 37 °C in 5 % CO2 and protected from light. The resulting formazan crystals were extracted with acidified isopropanol and quantified with the optical densities (OD) recorded spectrophotometrically. SDS 5 % aq. and 1 x PBS treated (three units / positive and negative control) epidermis units were used as positive and negative controls, respectively. For each treated tissue, viability was expressed as a percentage relative to negative control. The test chemical is identified as requiring classification and labelling according to UN GHS (Category 2 or Category 1), if the mean relative viability after 15 minutes exposure and 42 hours post incubation is less or equal (≤) to 50 % when compared to the viability values obtained from the negative control.

In this in vitro skin irritation test using the EPISKIN model, the test item L-Arabinose did not show significantly reduced cell viability in comparison to the negative control (mean relative viability: 93 %). All obtained test item viability results were above 50 % when compared to the viability values obtained from the negative control. Therefore the test item was considered to be non-irritant to skin. Positive and negative controls showed the expected cell viability values within acceptable limits. The experiment was considered to be valid.