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This outbreak highlights a number of significant factors related to most pseudomonas folliculitis outbreaks. The bath water had not been changed in more than four weeks which led to a build-up of high levels of organic carbon. There was an extended interval of six days between subsequent OTD chlorine residual tests, allowing the chlorine residual to decrease to low levels between tests. It should also be noted that the OTD test, by design, measures both the active free chlorine and the inactive combined chlorine residual. Therefore OTD residual readings in the low normal range may actually represent below normal free active chlorine residual levels. The following measures are suggested to reduce the growth of pseudomonads in hot tubs and whirlpool baths and to prevent subsequent cases of pseudomonas folliculitis: 1. The OTD chlorine residual should be checked every day. The residual should be well above the minimum level suggested for the bath. Or, preferably, an automatic chlorinator should be installed. This device measures the free chlorine residual and automatically adds chlorine to keep the residual in the desired range. 2. The water in the bath should be changed at least every eight weeks in order to reduce the total organic carbon level. The water should be changed more frequently if the bath is used by a large number of persons. 3. If an outbreak of pseudomonas folliculitis is associated with a bath, the water should be changed and the bath washed with a chlorine-based solution. Also, the method of keeping the chlorine residual in the operating range should be re-evaluated.