Glutaric acid

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 13 September 2016 to 15 September 2016

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 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: Method B.40bis of Commission Regulation (EC) No 440/2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Glutaric acid

EC Number:

203-817-2

EC Name:

Glutaric acid

Cas Number:

110-94-1

Molecular formula:

C5H8O4

IUPAC Name:

pentanedioic acid

Test material form:

solid: particulate/powder

In vitro test system

Test system:

human skin model

Source species:

other: Reconstructed Human Epidermis

Details on animal used as source of test system:

Not applicable

Vehicle:

unchanged (no vehicle)

Details on test system:

REMOVAL OF TEST MATERIAL AND CONTROLS
- Rinsing was achieved by filling and emptying each tissue under a constant soft stream of DPBS to gently remove any residual test item. Excess DPBS was removed by blotting the bottom of the tissue insert with tissue paper.

DYE BINDING METHOD
- Dye used in the dye-binding assay: MTT
- Spectrophotometer: Anthos 2001 microplate reader
- Wavelength: 562nm (OD562)

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 25 mg

NEGATIVE CONTROL
- Amount(s) applied (volume or weight with unit): 50 μL
- Lot/batch no. (if required): 3011859
- Purity: Not supplied

POSITIVE CONTROL
- Amount(s) applied (volume or weight with unit): 50 μL
- Lot/batch no. (if required): SLBM9898V
- Purity: 7.92N (specification 7.92 – 8.08N)

Duration of treatment / exposure:

3 and 60 minutes

Number of replicates:

Duplicate

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 minutes

Value:

24.6

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

60 minutes

Value:

9.6

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

- OTHER EFFECTS:
- Direct-MTT reduction: none
- Colour interference with MTT: none

DEMONSTRATION OF TECHNICAL PROFICIENCY:

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

The relative mean viabilities for each treatment group were as follows:

Exposure period	Percentage viability
	Negative control	Positive control	Test item
3 minute	100	4.2	24.6
60 minute	100	3.7	9.6

Applicant's summary and conclusion

Interpretation of results:

Category 1A (corrosive) based on GHS criteria

Conclusions:

The Relative mean tissue viability calculated as a percentage of the negative control was 9.6% after the 60-minute exposure and 24.6% after the 3 minute exposure. The test item met the criteria for classification as corrosive to the skin (Skin Corr 1A) according to Regulation (EC) No.1272/2008 on the Classification, Labelling and Packaging of Substances and Mixtures.

Executive summary:

The in vitro skin corrosion of the test substance was determined in accordance with the OECD Guideline for Testing of Chemicals 431. The purpose of this test is to evaluate the corrosivity potential of the test item using the EpiDerm™ Human Skin Model after treatment periods of 3 and 60 minutes. Corrosion is directly related to cytotoxicity in the EpiDerm™ tissue. Cytotoxicity is determined by the reduction of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) to formazan by viable cells in the test item treated tissues relative to the corresponding negative control. The results are used to make a prediction of the corrosivity potential of the test item.

Duplicate tissues were treated with the test item for exposure periods of 3 and 60 minutes. At the end of the exposure period the test item was rinsed from each tissue before each tissue was taken for MTT-loading. After MTT loading each tissue was placed in 2 mL Isopropanol for MTT extraction.

At the end of the formazan extraction period each well was mixed thoroughly and triplicate 200 μL samples were transferred to the appropriate wells of a pre-labeled 96-well plate. The optical density (OD) was measured at 562 nm (OD562). Data are presented in the form of percentage viability (MTT reduction in the test item treated tissues relative to negative control tissues).

The Relative mean tissue viability calculated as a percentage of the negative control was 9.6% after the 60-minute exposure and 24.6% after the 3 minute exposure. The test item met the criteria for classification as corrosive to the skin (Skin Corr 1A) according to Regulation (EC) No.1272/2008 on the Classification, Labelling and Packaging of Substances and Mixtures.