Lithium methanolate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999-08-02 to 1999-08-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

The Corrositex assay is used as a standardized and quantitative in vitro corrosivity test. The test is based on the time that is required for the test sample to pass through a biobarrier membrane and produce a change in the Chemical Detection System (CDS). The Packing Group is determined by the time interval required to break through the biobarrier matrix.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Lithium methanolate

EC Number:

212-737-7

EC Name:

Lithium methanolate

Cas Number:

865-34-9

Molecular formula:

CH4O.Li

IUPAC Name:

lithium methanolate

Details on test material:

- Name of test material (as cited in study report): Lithium methoxide in methanol (519-01a)
- Physical description: Pale brown non-viscous liquid

In vitro test system

Test system:

artificial membrane barrier model

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

other: Mean breakthrough time

Vehicle controls validity:

not applicable

Negative controls validity:

not applicable

Positive controls validity:

valid

Remarks on result:

other: Mean breakthrough time of 21:05 min was observed.

Any other information on results incl. tables

The results of the Categorization Screen indicated that the test article, lithium methoxide in methanol (519 -01a), fell into category 1. Therefore, it was evaluated using the timetable in Table 1.

The test article was examined in a single trial (four replicates) to determine the packing group and the breakthrough time. Table 3 summarizes the results of the definitive Corrositex assay for the test article and the positive control. A control (color blank) vial was included in the assay only for the purpose of comparison with the test article and positive control. Therefore, no breakthrough results are reported for this vial. The results of the positive control, NaOH (EM Science, lot# 342774499, >97% purity), fell within two standard deviations of the historical mean, thereby meeting the acceptance criteria.

One of the four replicate vials showed a break through at 1:35:00 (elapsed time presented as hr:min:sec) which was much longer than the other three vials. This value was considered an outlier and was not used in the mean break through time calculation.

Table 3: Results of the definitive Corrositex assay

Test article	Break Through Time (min:sec)					Packing group	pH*
	Vial 1	Vial 2	Vial 3	Vial 4	Mean
Lithium methoxide	22:00	20:26	20:49	01:35:00(a)	21:05	II	13
NaOH	11:22	NA	NA	Na	11:22	NA	NA

* 100 µL : 1 mL solution in deionized water

NA: Not Applicable

(a): Outlier, not included in the mean break through time calculation

Applicant's summary and conclusion

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Conclusions:

Based on the results of the Corrositex test, the test substance is corrosive.

Executive summary:

The purpose of this Corrositex Assay was to evaluate the potential corrosivity of the test substance, lithium methoxide in methanol, as measured by its penetration through a calibrated biobarrier into a chemical detection system (CDS). The test article was tested in one definitive assay (four replicates) to measure the mean breakthrough time and determine the Packing Group. Based on the determined breakthrough time, lithium methoxide was assigned to Packing Group II in the Corrositex Assay. Based on the results of the Corrositex test, the substance has to be classified as Category 1 B (corrosive) based on GHS criteria.