To obtain a bactericide which can selectively kill bacteria belonging to the genus Legionella and allows a wide range of applications.
This bactericide is obtained by dissolving and including silicate and/or alkali hydroxide as active ingredient(s) in water. As the silicate, alkali silicates such as sodium metasilicate, sodium silicate, and potassium silicate are preferably used. As the alkali hydroxide, alkali hydroxides such as sodium hydroxide and potassium hydroxide are preferably used. Preferable alkalinities of these components are 0.012-0.1N with respect to silicate, or silicate and sodium hydroxide, and 0.005-0.1N with respect to alkali hydroxide. The bactericide is preferably used to sterilize water used in a microorganism-preventing system such as '24-hour bath'.
ICHIHARA KAZUYOSHI
KATO KEIKO
