What is a legionella risk assessment?

A risk assessment for legionella is carried out in buildings to determine and control whether risk factors for legionnaires' disease are present. This is a severe form of lunar inflammation caused by bacteria called legionella.

It is a droplet infection that is transmitted via the air, more precisely through inhalation. Dangerous is the water mist that is created, for example, when using a tap with an aerator, when taking a shower or by poorly maintained air conditioning systems. Employers are required by law to assess and control the risks associated with Legionella - especially landlords, hotel operators and hospital administrators.

This article deals with the following topics:

1. Why a checklist should be used

2. Risk factors that every checklist should cover

3. A digital solution for the hazard analysis of legionella

Why use a checklist for the risk assessment of legionella?

A checklist makes it easier for landlords or other responsible persons to check the water systems in their buildings for legionella. By using a checklist no point of examination is forgotten and everything is properly documented. This makes it easier to ensure a safe and legionella-free workplace or living space for those present.

A legionella risk assessment checklist provides the inspector with a guide that enables him to conduct thorough inspections of water systems and comply with legal requirements to prevent the growth of legionella bacteria. It is important to carry out legionella inspections regularly. Legionnaires' disease can cause serious damage or even death to those affected by it.

These risk factors should be covered by every checklist

The outbreak of legionnaires' disease in the US city of Flint, Michigan has reached negative fame worldwide. The infection crisis was triggered by a faulty drinking water supply that made tap water danger to the inhabitants of Flint. A faulty action that could have been prevented by early risk assessment and subsequent intervention.

In order to avoid getting into a similar situation and endangering human lives, the following three factors should always be included in a legionella risk assessment checklist so that property managers can effectively combat the legionella bacteria:

1. superfluous or no longer used pipelines

Inappropriately removed pipelines or rarely used drainpipes without regular water flow can cause stagnant water in piping systems - a primary breeding ground for legionella. For example, if a drain has been removed and the pipes that once led to it have been covered, an area is created where water accumulates.

This danger can be avoided by redesigning superfluous piping, by remeasuring the hot and cold water system and updating the complete schematic. This includes a new evaluation of the water flow, the water treatment program and a written scheme for combating legionella.

2. infected cold water storage tanks

A further prerequisite for the rapid reproduction of legionella is the absence of residual disinfectants such as chlorine in cold water storage tanks. Routine cleaning and disinfection of the cooling towers and the hot and cold water systems should take place at least once every six months. The procedure should include the initial concentration of oxidising biocide used for the disinfection stages before and after cleaning, the contact time for each stage and the methods for carrying out the cleaning, including removal of packaging.

3. lukewarm water temperature

Warm water temperatures of 25-42 degrees Celsius (77°-108°F) favour the washing of legionella. Therefore, the temperature of hot and cold tap water should be at 50 degrees Celsius (122°F) or more or 20 degrees Celsius (68°F) or less, while the water temperature inside the boiler should be at or above 60 degrees Celsius (140°F). The installation of temperature sensors proactively helps to monitor the correct temperature ranges.

Perform a risk assessment for legionella with Lumiform digitally

Property managers can effectively prevent legionella by regularly using a checklist, which can be used to check the condition, cleanliness and correct temperature of hot and cold water systems and document the data.

Using a mobile app like Lumiform instead of paper offers many advantages. Any risk assessment for legionella can be carried out simply by tablet or smartphone - online or offline. With the desktop software, the checklist is created, and later the data collected on-site is evaluated. This significantly reduces the risk of quality losses, documentation errors and damage to reputation.

Other advantages of a digital checklist for Legionella are:

• Generate real-time data via internal processes. This makes quality and safety measurable and allows processes to be continuously optimized based on the data.


• Reports are created automatically - this saves the complete postprocessing.


• Increase the efficiency of internal processes: Through more efficient communication within the team, with third parties and with management, as well as faster reporting of incidents, incidents are solved up to 4x faster than before.


• Save time by simplifying the analysis of all data and identifying areas that need special attention more quickly.


• Continuous improvement of quality and safety: The flexible checklist building block system allows hazard analyses to be continuously optimized. Since Lumiform guides the inspector through the test, no training is required.