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Hydrolysis:

The test article, hydroxypropylated .beta.-cyclodextrin , was tested in The Abiotic Degradation by hydrolysis at three different pH values according to OECD Guideline 111.

Hydrolysis is one of the most important naturally occurring reactions in the environment and consequently represents one of the most important degradation pathways. Hydrolysis is defined as the reaction of chemicals with water resulting in the addition of water to the chemical, the substitution of OH- for a group in the chemical, or degradation of the chemical by another hydrolytic pathway. While known to be independent of factors such as sunlight, presence or absence of microbial populations and extent of oxygen supply, the rate of hydrolysis is dependent on pH, temperature and the concentration of the chemical. It has been demonstrated by Mabey and Mill (1978) that for twelve classes of organic chemicals, rates of hydrolysis obtained in the laboratory are comparable to naturally occurring rates. Therefore, hydrolysis studies provide useful information for the evaluation of the persistence of a chemical in the aquatic environment.

The objective of this study was to determine ifhydroxypropylated .beta.-cyclodextrinis stable in water at three different pH values so that the importance of hydrolysis as a transformation route can be better assessed with regard to the overall potential for persistence and/or degradation of the test substance in the environment. This study was initiated on 8 April 1997, the day the Study Director signed the protocol, and was completed on the day the StUdy Director signed the final report. The experimental phase of this study was conducted from 8 to 13 May 1997 at Springborn Laboratories, Inc. (SLJ), located in Wareham, Massachusetts. The analytical chemistry was conducted at Midwest Research Institute, Kansas City, Missouri and the data is archived there. The test system raw data and the final report produced during this study are stored in Springborn's archives at the above location.

After 5 days at 50°C +/- 1 °Chydroxypropylated .beta.-cyclodextrindegraded by 1.1%, -4.2%, and 1.9% at pH 4, 7, and 9, respectively. Since the degradation at all pHs tested was less than 10% after being exposed to optimum hydrolysis conditions (i.e., 5 days at 50 +/-0.1 °C),hydroxypropylated .beta.-cyclodextrinis considered hydrolytically stable.