Propionic anhydride

Additional toxicological data

Administrative data

Endpoint:

additional toxicological information

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study was conducted under GLP in a modern laboratory

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD 111

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

other: EEC Annex V, Part C7

Principles of method if other than guideline:

The purpose of this test is to determine tbe potential of propionic anhydride to undergo hydrolysis in a saline:rat serum solution (1:3, v:v). A saline:serum mixture was used because adding the test material (in acetonitrile) directly to tbe serum resulted in a cloudy solution, suggesting serum protein denaturation by either tbe test substance, the solvent (acetonitrile), or both. Information pertaining to the hydrolytic stability of propionic anhydride is useful for hazard identification and risk assessments. If the hydrolysis reaction is fast, then hazard identification and risk assessment should focus on propionic acid, tbe product of hydrolysis. Additional animal testing on the anhydride would be unnecessary.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Propionic anhydride

EC Number:

204-638-2

EC Name:

Propionic anhydride

Cas Number:

123-62-6

Molecular formula:

C6H10O3

IUPAC Name:

propanoyl propanoate

Details on test material:

Name: propionic anhydride
EAN: 901291
Sample Reference Number: 05-01
CAS Number: 123-62-6
Date Received: May 10,2001

Results and discussion

Any other information on results incl. tables

Determination	K obs	t 1/2  minutes
1	4.4478	0.16
2	6.1200	0.11
3	5.1805	0.13
mean	---	0.13

Applicant's summary and conclusion

Executive summary:

The potential of the test substance to undergo hydrolytic degradation in rat serum was studied in GLP conformance using a procedure similar to those outlined in: OECD Guideline No. 111, EEC's Annex V, Part C.7, EPA's Chemical Fate Guidelines and EPA's Pesticide Assessment Guidelines. The hydrolysis testing was performed at 26 ± 0.5 C in a saline:rat serum solution (1:3, v:v). This diluting solution contained twenty-five percent by volume of physiological saline prior to the introduction of the test substance. A test substance stock solution was prepared in acetonitrile. The test systems were prepared by adding 10 uL aliquots of the stock solution to 0.5 mL of the saline:rat serum solution (1:3, v:v), resulting in an approximate acetonitrile concentration of 2% in each test system. Inorder to quench hydrolysis, acetonitrile was then added at timed intervals to achieve 80% acetonitrile by volume in each test system. Test solutions were analyzed for the test substance using gas chromatography with flame ionization detection (GC/FID). The initial work done in rat serum indicated that the test substance hydrolyzed at such a fast rate that our conventional means of test system preparation and multiple sampling from a single test system would not be adequate for determining the half-life. Therefore, the study was performed by preparing eight separate test systems and quenching the hydrolysis in each test system at timed intervals during a 2-minute period. The change in test substance concentration, over time, was calculated and reported as the percent hydrolysis. The natural logarithm (In) of the test substance concentration (mg/L) versus time (minutes) was plotted and the best-fit line, as determined by a linear regression analysis, was used to calculate the observed rate constant (Kob) and the half-life (t ½). The study was performed three times. The mean (n=3) half-life of the test substance in the saline solution of rat serum was 0.13 minutes.