What is the L8 Approved Code of Practice? (ACOP)

The L8 Approved Code of Practice applies to the control of Legionella bacteria in any undertaking involving a work activity. It also applies to premises controlled in connection with a trade, business or other undertaking where water is used, stored and there is a reasonably foreseeable risk of exposure to Legionella bacteria (L8 ACOP, paragraph 22).

The ACOP L8 regulations state that a sufficient risk assessment is the first step in Legionnaires’ Disease prevention. The objective is clear that a Legionella Risk Assessment should seek to identify all water systems were Legionella bacteria could potentially grow. It also requires that an assessment of risk to people being exposed to contaminated aerosols as a result of this.

All water systems should be taken into consideration as part of the Legionella Risk Assessment. However, there are some aspects which are highlighted in the ACOP L8 Code of Practice as higher risk. These include:

· Hot & Cold water systems  

· Cooling water systems, cooling towers and evaporative condensers

· Spa pools

· Spray humidifiers, misters, air washers and wet scrubbers

· Safety showers, sprinklers, vehicle wash systems

· Fountains and water features 

· Any other system containing water in which Legionella could grow and be released in aerosol droplets

Where Does The Risk Come From?

One of the key risks identified for Legionella contamination in Dental Practices is related to the biofilms that are prone to forming on dental unit waterlines. The majority of organisms which can be present on this film are generally harmless, however they have the potential to harbour harmful organisms such as Legionella bacteria.

It is also known that Legionella bacteria can be amplified in the biofilm present on dental units. This can then lead to escalation levels with the potential for inhalation or direct contamination of surgical wounds.

The Dental unit water lines have the most potential and obvious route of exposure for both patient and dentist. However, it is also important to confirm that the standard hot and cold water systems within the building are of low risk. This can include domestic hot and cold water taps, reception areas, practice and any showers, storage tanks or other water outlets or storage mediums within the demise. The Legionella Risk Assessment will assess all of these factors.