(E)-2-methylpent-2-en-1-oic 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:

18 November 1999 - 19 November 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)

Version / remarks:

28 July 2015

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(E)-2-methylpent-2-en-1-oic acid

EC Number:

241-026-4

EC Name:

(E)-2-methylpent-2-en-1-oic acid

Cas Number:

16957-70-3

Molecular formula:

C6H10O2

IUPAC Name:

(2E)-2-methylpent-2-enoic acid

Test material form:

liquid

In vitro test system

Test system:

artificial membrane barrier model

Vehicle:

unchanged (no vehicle)

Details on test system:

SOURCE AND COMPOSITION OF MEMBRANE BARRIER USED
- Was the Corrositex® test kit used: yes
- Components: biobarrier matrix powder
- Apparatus and preparation procedures: a scintillation vial containing the biobarrier matrix powder was placed in a water bath on a stirring hot plate. The entire contents of the biobarrier diluent vial were added slowly to the matrix powder. The solution was warmed to 60-68°C to solubilize the biobarrier matrix. Two hundred µL of the solubilized matrix solution were pipetted into each membrane disc. The membrane discs were then stored at 2-8°C in a refrigerator at least overnight before being used for corrosivity testing.

WAS THE COMPATIBILITY TEST PERFORMED: yes

WAS THE TIMESCALE CATEGORY TEST PERFORMED: yes

TEMPERATURE USED DURING TREATMENT: not indicated

METHOD OF DETECTION
- Chemical detection system

METHOD OF APPLICATION: the substance was directly applied to the membrane disc.

NUMBER OF REPLICATES: 4

NUMBER OF INDEPENDENT EXPERIMENTS TO DERIVE FINAL PREDICTION: 1

PREDICTION MODEL / DECISION CRITERIA: see table 1

ACCEPTABILITY OF TEST: The Corrositex Assay was accepted if the positive control break through time fell within two standard deviations of the historical mean. The historical mean is recalculated approximately every three months from a database consisting all break through times for the positive control, except those from assays which were considered invalid due to technical errors.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount applied: 500 µL

NEGATIVE CONTROL
- Amount applied: not indicated

POSITIVE CONTROL
- Amount applied: not indicated

Duration of treatment / exposure:

The vial was observed for three minutes, if no color change was detected, the substance was applied to the membrane disc repeatedly at one minute intervals until a color change was observed.

Number of replicates:

4

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

penetration time (in minutes)

Run / experiment:

Single run/mean of 4 replicates

Value:

ca. 180

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks:

14 min, 10 sec

Other effects / acceptance of results:

- No color change was observed in the negative control. The results of the positive control fell within the historical range of 9:07 - 14:41 min:sec. Therefore, the system was considered to be valid.
- The substance did not induce a break through in color change; i.e. no distinct color change was observed streaming from the biobarrier matrix within the Chemical Detection System (CDS). However, approximately 3 hours into the assay, the CDS was observed to have a homogeneously distributed, darker orange appearance, when compared to the blank. After 3.5 hours, a second blank control was setup, complete with a membrance disc, to verify that the darker color observed in the test samples was not due to shadowing of the CDS by the membrane disc. Although no precise break through time could be determined, it was clear from the results that a break through, indicative of a corrosive response, was detected in all four vials prior to the 3 hour and 30 minutes observation, and presumably at approximately 3 hours.

Applicant's summary and conclusion

Interpretation of results:

other: Corrosive category 1C

Remarks:

according to EU CLP (EC No. 1272/2008 and its amendments).

Conclusions:

In a Corrositex assay, the substance induced a colour change after 3.5 hours into the assay. Based on this result, the substance is classified as corrosive to the skin, category 1C.

Executive summary:

A Corrositex assay was performed, equivalent to OECD guideline 435 and non-GLP, to assess the substance's potential to be corrosive to the skin. Prior to the start of the corrosivity testing, a qualification screening and a pH screening were performed to determine whether the substance could be analyzed in this system. The substance induced an immediate color change in the Chemical Detection System (CDS) qualification tube and the pH of the substance was 2.5. Membrane discs were prepared by adding a scintillation vial to a biobarrier matrix powder. In the corrosivity study, 500 µL of the substance was applied to membrane discs which were placed into a vial containing the CDS. A positive control of NaOH and a negative (blank) control were included. The substance did not induce a distinct color change from the biobarrier matrix within the CDS. Therefore, no precise break through time could be determined. However, it was clear from the results that a break through, indicative of a corrosive response, was detected in all four vials prior to the 3 hour and 30 minutes observation, and at approximately 3 hours. The validity of the test system was shown by the results of the positive control which fell within the historical range and the results of the negative control, which did not induce a colour change. Based on this result, the substance is classified as corrosive to the skin, category 1C according to Regulation (EC) No. 1272/2008 and its amendments.