Rosin, reaction products with acrylic 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:

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

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Rosin, reaction products with acrylic acid

EC Number:

280-192-2

EC Name:

Rosin, reaction products with acrylic acid

Cas Number:

83137-13-7

Molecular formula:

N.A. - UVCB substance

IUPAC Name:

Rosin, reaction products with acrylic acid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 3M Company, Lot 646729
- Expiration date of the lot/batch: 19 November 2018

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature and humidity

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: The test material was used as recieved (yellow solid)

FORM AS APPLIED IN THE TEST (if different from that of starting material): The test material was used as recieved (yellow solid)

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

foreskin from a single donor

Source strain:

other: Human

Details on animal used as source of test system:

Source: EpiDerm™ tissues, Lot No. 26717 Kit D, were received from MatTek Corporation (Ashland, MA) on 25 Jul 2017

Justification for test system used:

The EpiDerm™ Skin Model closely parallels human skin, and is recommended by test guidelines. Validation studies have reported that tests employing human skin models are able to reliably discriminate between known skin corrosives and non-corrosives.

Vehicle:

other: Tissue Culture Water, Lot No. RNBF6962 (TCH2O)

Details on test system:

SKIN DISC PREPARATION
- Procedure used: MTT Reduction Assay

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37C
- Temperature of post-treatment incubation (if applicable): 37C

REMOVAL OF TEST MATERIAL AND CONTROLS
- Number of washing steps: 2; rinsed with phosphate buffered saline (PBS)

DYE BINDING METHOD
- Dye used in the dye-binding assay: Methyl thiazole tetrazolium (MTT) (diluted in Dulbecco's Modified Eagle's Medium (DMEM))
- Spectrophotometer: Microplate reader (μQuant Plate Reader, Bio-Tek Instruments, Winooski, VT).
- Wavelength: 540 nm

NUMBER OF INDEPENDENT TESTING RUNS / EXPERIMENTS TO DERIVE FINAL PREDICTION: Tested in duplicate

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- The test substance is considered to be corrosive to skin if mean viability at 3 minutes is <50% or if mean viability at 3 minutes is >/=50% and mean viability at 60 minutes is <15%.
- The test substance is considered to be non-corrosive to skin if the mean viability at 3 minutes is >/=50% and mean viability at 60 minutes is >/=15%.

- Justification for the selection of the cut-off point(s) if different than recommended in TG 430: Cut-off points used are based on OECD protocol 431 (in vitro skin corrosion: reconstructed human epidermis (RHE) test method)

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
- Concentration (if solution): Neat

VEHICLE
- Amount(s) applied (volume or weight with unit): 25 uL tissue culture water (TCH2O)
- Lot/batch no. (if required): Lot No. RNBF6962

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 uL
- Concentration (if solution): Neat

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50 uL
- Concentration (if solution): Neat

Duration of treatment / exposure:

3 minutes and 60 minutes

Duration of post-treatment incubation (if applicable):

3 hour MTT incubation period

Number of replicates:

2

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Remarks:

3 minutes

Run / experiment:

Test material (MTDID 28640)

Value:

103.3

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Remarks:

60 minutes

Run / experiment:

Test material (MTDID 28640)

Value:

97.7

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Results 3

Irritation / corrosion parameter:

% tissue viability

Remarks:

3 minutes

Run / experiment:

Tissue culture water (Negative Control)

Value:

100

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Results 4

Irritation / corrosion parameter:

% tissue viability

Remarks:

60 minutes

Run / experiment:

Tissue culture water (Negative Control)

Value:

100

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Results 5

Irritation / corrosion parameter:

% tissue viability

Remarks:

3 minutes

Run / experiment:

Potassium Hydroxide Solution, 8.0 N (Positive Control)

Value:

32.7

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Results 6

Irritation / corrosion parameter:

% tissue viability

Remarks:

60 minutes

Run / experiment:

Potassium Hydroxide Solution, 8.0 N (Positive Control)

Value:

2.1

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

The mean optical density of the negative control tissues was 1.721 at 3 minutes and 2.067 at 60 minutes, which met the acceptance criterion (OD >/= 0.8).

The mean relative tissue viability of the 60-minute positive control was 2.1 %, which met the acceptance criterion <15%).

Viability differences between the two identically treated tissues in all samples and controls at 3 minutes were 0.0% to 11.5%. Viability differences between the two identically treated tissues at 60 minutes were 0.1 % to 10.7%. Inter-tissue viability differences at both time pOints met the acceptance criterion (<30%).

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the results of the study, the test article is not considered to be corrosive in the EpiDerm Skin Corrosivity Test (OECD 431).

Executive summary:

The in vitro skin irritation/corrosion potential of the test article (yellow solid; Lot 646729) was evaluated using the MatTek EpiDerm Skin Corrosivity Test. The study was performed in compliance with GLP. The study design was based on the MatTek MTT Effective Time-50 (ET-50) Protocol (protocol no. 711-02). The test article was prepared in tissue culture water (TCH2O). EpiDerm samples were incubated in 6-well tissue culture plates containing assay medium for 1 hour. After incubation, 25 mg of the test article plus 25 uL TCH2O were applied to the top of each EpiDerm tissue. The test article remained in contact with the tissue for 3 and 60 minutes. A negative control (50 uL of TCH2O) and a positive control (50 uL of potassium hydroxide solution, 8.0 N) were tested in parallel. Each treatment with test article or control was conducted in triplicate. At the end of the exposure period, each EpiDerm tissue was rinsed with phosphate buffer saline (PBS) and transferred to a 24-well microplate containing 300 uL of MTT solution (1 mg/mL MTT in Dulbecco's Modified Eagle's Medium (DMEM)); a negative control, 100 uL of TCH2O was tested concurrently. Tissues were then returned to the incubator for a 3-hour MTT incubation period. Following the MTT incubation period, each EpiDerm™ tissue was rinsed with PBS and then treated overnight with 2.0 ml of extractant solution (isopropanol) per well. The absorbency of an aliquot of the extracted MTT formazan was measured in triplicate at 540 nm using a microplate reader. The mean absorbance value for each time point was calculated from the optical density (OD) of the duplicate tissues and expressed as percent viability for each sample. A mean viability at 3 minutes of greater than or equal to 50% and a mean viability at 60 minutes greater than or equal to 15% indicates the material was non-corrosive. The positive and negative controls performed as expected which indicated test validity. The cell viability for tissue treated with the test material was 103.3% and 97.7% at 3 and 60 minutes, respectively. Based on the results of the study, the test material MTDID 28640 is not considered to be corrosive in the EpiDerm Skin Corrosivity Test (OECD 431). In the absence of additional information, and to be conservative a classification of skin irritant, Category 2 was assinged.