N,N-bis(1-methylethyl)formamide

Endpoint summary

Description of key information

Skin:

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.

 

Eye:

The Bovine Corneal Opacity and Permeability Test is performed on the test substanc. The IVIS value is 58.08, the test substance is eye corrosive.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

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)

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)

Specific details on test material used for the study:

Batch number: M-O303190723301F
Purity: 99.68%

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

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 minutes exposure

Value:

88.6

Vehicle controls validity:

valid

Positive controls validity:

valid

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%).

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.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 30 Mar 2021 to 01 Apr 2021

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying Ocular Corrosives and Severe Irritants)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch number: M-O303190723301F
Purity: 99.68%

Species:

cattle

Details on test animals or tissues and environmental conditions:

SOURCE OF COLLECTED EYES
- Source: Bovine eyes (from cattle at least six months old) were obtained from a local abattoir by Spear Products (Coopersburg, PA) and transported to MB Research in Hanks’ Balanced Salt Solution (HBSS) with penicillin-streptomycin on ice, in an insulated cooler, on 01 Apr 2021.
- Selection and preparation of corneas: The eyes were examined after receipt from the abattoir. Any cornea with gross abnormalities (e.g., neovascularization, pigmentation, opacity or scratches) was discarded.

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

0.75 ml

Duration of treatment / exposure:

10 minutes

Duration of post- treatment incubation (in vitro):

2 hours

Number of animals or in vitro replicates:

3

Details on study design:

NUMBER OF REPLICATES: 3

NEGATIVE CONTROL USED: MEM

POSITIVE CONTROL USED: 100% Ethanol

TREATMENT METHOD: closed chamber

POST-INCUBATION PERIOD: yes

REMOVAL OF TEST SUBSTANCE
- Number of washing steps after exposure period: After 10 (± 1) minutes, the test and control
articles were removed from the epithelium of the corneas and anterior chamber of the holder by washing with MEM containing phenol red. A final rinse was made with MEM without phenol red. The anterior and posterior chambers of the holders were then refilled with fresh MEM.
- POST-EXPOSURE INCUBATION: All corneas were incubated at 32 (± 1)°C for an additional two hours, MEM was then removed and replenished in each cornea holder.

METHODS FOR MEASURED ENDPOINTS:
- Corneal opacity: The opacity of each cornea was measured by comparing the treated cornea to the blank supplied with the opacitometer.
- Corneal permeability: passage of sodium fluorescein dye measured with the aid of Spectronic 20-D Colorimeter Spectrophotometer (OD490)

SCORING SYSTEM: In Vitro Irritancy Score (IVIS)

DECISION CRITERIA: the decision criteria as indicated in the TG was used.

Irritation parameter:

in vitro irritation score

Value:

58.08

Negative controls validity:

valid

Positive controls validity:

valid

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Conclusions:

The test substance is eye corrosive.

Executive summary:

The Bovine Corneal Opacity and Permeability Test is performed on the test substanc. The IVIS value is 58.08, the test substance is eye corrosive.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Skin irritation / corrosion:

EpiDerm™ Skin Corrosivity Test OECD 431: mean viability at 3 minutes and 60 minutes are 88.6% and 10%. The test substance is skin corrosive.

According to Regulation (EC) No 1272/2008, table 3.2.1, this substance should be classified as Category 1 for this endpoint.

Eye irritation:
Bovine Corneal Opacity and Permeability Test OECD 437: IVIS value is 58.08, the test substance is eye corrosive.
According to Regulation (EC) No 1272/2008, table 3.3.1, this substance should be classified as Category 1 for this endpoint.