Legionella bacteria are common and can occur naturally in the environment in lakes, rivers etc. but usually in relatively small amounts. They have been found in water at temperature between 6°C and 60°C. There is an optimum temperature of between 20°C and 45°C that seems to favour their proliferation and they are normally killed off by temperatures above 60°C but can survive for short periods at temperatures of up to 80¡C. The initial stage in the prevention of legionella is a Risk Assessment. The purpose of the Assessment is to enable a valid decision to be made regarding the risk to health, i.e. whether the potential for harm to health from exposure is reasonably foreseeable and to ensure that adequate precautionary measures are taken. Also what measures for prevention, or adequate control, to minimise the risk from exposure to legionella, is taken.
