Legionella Testing

Legionella bacteria are biologically active in freshwater habitats such as lakes and streams. When bacteria thrive and spread in human-made building water systems, they can pose a health hazard. Legionellosis is a collective term for diseases caused by the legionella bacteria. Legionnaires’ disease is a potentially fatal type of pneumonia that affects everyone.

Legionella Testing

Legionella bacteria could affect people through the water as a medium, and this refers to commercial buildings that have cooling towers. When cooling water in the commercial buildings is being contaminated with Legionella disease, the water is being supplied through the water system, straight goes to the water distribution system where heat being transferred and distributing the cool water back to the HVAC system. The HVAC system will then circulate the cool water to produce cool air, which then distributed through the HVAC system. If Legionella bacteria is present in the water, the occupants will get infected once they breathe the indoor air of the facilities.

Legionella bacteria increases the risk of infection for those who

Individuals over the age of 45
Smokers and Heavy drinkers
Anyone with chronic respiratory or kidney disease
Diabetes, lung or heart disease 
Those with a weakened immune system

IAQ Diagnostics solutions to Test Legionella

Cultured Sample
Direct Fluorescence Antibody (DFA)

What do we recommend?

Collective sampling needs to be taken from time to time, especially the cooling tower in the commercial buildings. The area of the main water supply also needs to be taken into consideration as it aligns with the process of where Legionella bacterias could be found and bred. Water sampling for Legionella testing should be carried out from different points as it needs to be compared and recorded to detect the starting root.

Frequently Asked Questions

To measure the possibility of exposure to legionella bacteria, a legionella risk assessment must be performed (ACOP L8 Page 12). These are systems:

  • Use of a cooling tower
  • Using an evaporative condenser
  • Hot/cold water
  • Also plant-based water

The Legionella Risk Assessor looks for any area that has water. Legionella risk criteria include:

  • The discovery of legionella
  • Temperature between 20˚C – 45˚C, adequate nutrients and available space for bacterial growth, e.g. an impenetrable layer of microbes that adhere to the inside of wounds.
  • Persons that may be affected by bacterial contamination
Consider a re-commissioning programme if your site is either closed down or has water systems shut down. For a very simple water system, 5 minutes of flushing can flush all the outlets. On larger systems, e.g. hotels, factories, large offices, and offices, refurbishing will require a more advanced chemical disinfection service with routine legionella sampling.

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