d. Sampling and storage: Collect samples for odor testing in glass bottles with glass or teflon-lined closures. Tests should be completed as soon as possible after collection of the sample. If storage is necessary, collect at least 500 ml of sample เท a bottle filled to the top; refrigerate, making sure that no extraneous odors can be drawn into this sample when the water cools. Plastic containers arc not reliable for odor samples.