substance; and(4) In withdrawing the bottes from the water bath at the period described. odlaug and Pflug(1978) point out that the most practical method of controlling the level of microorganisms in canning plant cooling water is by chlorinating the water(Mercer, 1956: Mercer and Somers(1957). Canning industry trade groups, such as the National Canner's Association(NCA, 1973, 1968) and can manufacturers and public health groups have established practical procedures for chlorinating canning plant cooling waters. The Food and Drug Administration(United States) requires commercial canners to have a measurable free chlorine residual at the water-discharge point of the container cooler(Federal Register, 1976)