N,N-bis(1-methylethyl)formamide

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 30 Mar 2021 to 22 Apr 2021

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

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 (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

N,N-bis(1-methylethyl)formamide

EC Number:

220-284-1

EC Name:

N,N-bis(1-methylethyl)formamide

Cas Number:

2700-30-3

Molecular formula:

C7H15NO

IUPAC Name:

N,N-Diisopropylformamide

Specific details on test material used for the study:

Batch number: M-O303190723301F
Purity: 99.68%

In vitro test system

Test system:

human skin model

Source species:

human

Justification for test system used:

The EpiDerm™ Skin Model closely parallels human skin, and is recommended by test guidelines.

Vehicle:

other: Tissue Culture Water (TCH2O)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: MatTek EpiDerm™ Skin Model (EPI-200)

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37±1°C
- Temperature of post-treatment incubation (if applicable):

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 100 μl of the test article were mixed with 1 ml of MTT solution (1 mg/ml thiazolyl blue tetrazolium bromide diluted in Dulbecco's Modified Eagle's Medium (DMEM)).
- Incubation time: The tissues were then returned to the incubator for an MTT incubation period
of 3 hours ± 10 minutes.
- Spectrophotometer: microplate reader (μQuant Plate Reader, BioTek® Instruments, Winooski, VT).
- Wavelength: 540 nm

NUMBER OF REPLICATE TISSUES: 3

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- The test substance is considered to be corrosive to skin if the viability after 3 minutes exposure is less than 50%, or if the viability after 3 minutes exposure is greater than or equal to 50 % and the viability after 1 hour exposure is less than 15%.
- The test substance is considered to be non-corrosive to skin if the viability after 3 minutes exposure is greater than or equal to 50% and the viability after 1 hour exposure is greater than or equal to 15%.

Control samples:

yes, concurrent vehicle

yes, concurrent positive control

Amount/concentration applied:

50 μl of the test article were applied to the top of each EpiDerm™ tissue.

Duration of treatment / exposure:

The test article remained in contact with the EpiDerm™ tissue for 3 minutes at room temperature and 60 minutes at 37±1°C, 5±1% CO2.

Number of replicates:

3

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 minutes exposure

Value:

88.6

Vehicle controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

60 minutes exposure

Value:

10

Vehicle controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

The mean OD of the negative control tissues was 1.686 at 3 minutes and 1.611 at 60 minutes, which met the acceptance criterion (OD ≥ 0.8).
The mean relative tissue viability of the 60-minute positive control was 2.5%, which met the acceptance criterion (<15%).
Viability differences between the two identically treated tissues in all samples and controls at 3 minutes were 2.5% to 4.1%. Viability differences between the two identically treated tissues at 60 minutes were 0.2% to 1.3%. Inter-tissue viability differences at both time points met the acceptance criterion (≤30%).

Applicant's summary and conclusion

Interpretation of results:

Category 1 (corrosive) based on GHS criteria

Conclusions:

The test substance is skin corrosive.

Executive summary:

The MatTek EpiDerm™ Skin Corrosivity Test is performed on the substance. The mean viability at 3 minutes and 60 minutes are 88.6% and 10%. The test substance is skin corrosive.