How to Prevent Legionnaires’ Disease in the Workplace
In this water safety review the experts at Legionella Control International provide practical guidance on how to prevent Legionnaires’ disease in the workplace
The article explains what Legionnaires’ disease is and where it comes from, what guidance is available to help those responsible for water safety manage these risks; and why the legionella risk assessment process and development of a water safety plan are fundamental early stage steps required to create a solid safety management process that will keep staff, patients, customers and visitors safe.
A version of this story dealing with the prevention of Legionnaires’ disease in the workplace appeared in Legionella Control International’s newsletter. To get it in your inbox, sign up for free here.
Preventing Legionnaires’ disease in the workplace
Most people have heard of Legionnaires’ disease, but few know much about it. This guide is intended to give you more information about the disease – what it is, how it is caught, and how employers have a legal duty to do everything they can to prevent an outbreak of Legionnaires’ disease in their premises. This applies to all businesses, premises, and locations, from hospitals to hotels, office buildings and warehouses.
What is Legionnaires’ disease?
Legionnaires’ disease is a serious form of pneumonia with a potentially high mortality rate of around 10-15%. This can vary depending on those affected and the circumstances surrounding the outbreak. For example, in some cases where an outbreak of Legionnaires’ has occurred in a hospital setting among groups of people who are particularly at risk, higher mortality rates have been seen.
What are the symptoms of Legionnaires’ disease?
The disease presents in much the same way as flu or pneumonia. In some instances, it may not be clear someone has Legionnaires’ without proper testing to confirm this diagnosis. Fever, a cough, a headache, and general aches and pains can all be present with the disease.
Are some people at greater risk than others from the disease?
Yes. It’s recognised that anyone could develop the disease if they inhale legionella bacteria contained in fine droplets of water suspended in the air, called an aerosol. However, some people are at greater risk, including those with lung conditions or other conditions that affect their immune system. The risk level increases once you reach the age of around 45-50. It has also been noted that men tend to be more susceptible to Legionnaires’ infections than women, although this does not mean that women are not at risk.
What happens if someone is diagnosed with the Legionnaires’?
If someone is unlucky enough to be diagnosed with Legionnaires’ disease, it is important to start their treatment straight away. It’s also important that the authorities try and identify where the individual caught it so action can be taken to prevent further infection in other people. It’s prudent to consider all the places the individual has been in the days before the symptoms appeared. In most cases, patients with Legionnaires’ disease tend to incubate the bacteria for between two and 10 days prior to symptoms starting. This timeframe allows scope to work out where the person may have encountered the bacteria.
How can you catch Legionnaires’ disease?
To catch the disease someone must inhale mist or tiny water droplets containing legionella bacteria to be able to develop the disease. These are known as aerosols. Cooling towers, hot and cold water systems, shower heads, taps, humidifiers, and even decorative fountains may spread the legionella bacteria if they are not properly cleaned and maintained. This information can assist people in identifying the source of an outbreak of Legionnaires’ disease.
What must employers do to minimise the risk posed by legionella bacteria?
The first step to minimise the risks posed by legionella bacteria is to consider where the risks are. A legionella risk assessment should focus on all water sources, whether hot or cold, and all aspects of the water system in use at the premises. This safety assessment must identify all the potential risk factors and areas that are present, such as:
- Domestic hot and cold water systems
- Process systems that use water
- Hot tubs and spa pools
- Cooling towers
- Neglected, disused, or infrequently used pipework, outlets, and similar features
- Ornamental fountains, hoses, and similar outdoor features
- Air conditioning systems and all associated features
These are just a few examples. Some won’t be relevant in all situations, while other premises may have specific risk areas to consider. For example, a hospital may have different risk factors in different areas, such as a ward catering to elderly patients, hydrotherapy pools for rehabilitation, wards that have been temporary “mothballed” allowing water to stagnate.
When considering the water safety risks associated with any of these features, and all others connected to the water system in that building or business, you should consider the following:
Water temperatures
Legionella readily multiplies when water temperatures are between 20 – 45 degrees Celsius, so water should be above or below this range to limit growth.
Food sources
The bacteria need to feed to grow and multiply, so reducing any sources of nourishment for the bacteria is hugely important.
How the water is used
Storing the water in tanks poses a bigger risk, as does recirculating it, so in these cases, steps must be taken to monitor temperature and water quality.
Aerosols
Is there a risk of spray or mist occurring in certain areas? Showers, cooling towers, and even ornamental fountains can all cause this to occur.
Susceptibility of people
Are there people who may be more susceptible to the effects of Legionnaires’ disease? For example the elderly, people with underlying health conditions or compromised immune systems etc.
Removing or limiting legionella risks
The gold standard to aim for when managing the risks from legionella bacteria in any water system is to remove the risk wherever it is practical to do so. For example, if there is a run of pipework that is no longer in use, it is easier to remove it to remove the associated risk. In this case, the risk would involve stagnant water sitting in the pipework, increasing the chance of bacterial growth. It would also lead to sludge and biofilms developing to feed the bacteria, further increasing the risk. Removal of the disused pipes or water outlets would remove the risk.
However, removal of risks isn’t always possible. In this situation, limitation is the best approach. Let’s assume the plumbing pipework is only infrequently used but cannot be removed as it is still occasionally needed. In this case, you’d assess the risk and then possibly adopt a management programme that allows for regular flushing through of the pipework and all connected outlets in that area. Keeping a record of this shows what you have done, and it can be checked in future too.
While flushing through outlets is one method of control, there are others. For instance, regular maintenance can help keep the system as clean and safe as possible. Dosing with disinfectants and chemicals may also be required if the risk assessment identifies this as an important step to take.
Even something as simple as keeping the water temperature below 20 degrees Celsius in the case of cold water, and above 50 degrees Celsius (55 degrees Celsius in hospitals and healthcare) in the case of hot water, is a crucial step in helping reduce the risks connected to the bacteria. By focusing on the control of water temperatures, removal of food sources, and proper dosing of the system, you can either kill off the bacteria or limit growth to keep it within safe levels.
In every case, the legionella or water safety risk assessment and subsequent approach to safety regarding legionella bacteria should be managed by someone experienced in and knowledgeable about what needs to be done – they must be competent to do the job. This is the responsible person. It is possible to choose someone from within the business or to hire an experienced water safety specialist from outside the business if preferred. In the case of any testing that may be required, external experts should always be sought for such purposes.
Do you need to keep records of the legionella control measures you take?
If you employ five or more people, then yes, you must keep proper records of your legionella control activities as indicated by the Health and Safety Executive (HSE). However, it is usually a good idea to do this anyway. It gives a written record of all the steps taken to maintain a safe water system, keep people safe and provides evidence should you need it.
Leading water safety specialists
Legionella Control International are water safety specialists and support organisations and those responsible for the control of waterborne pathogens such as legionella bacteria in the workplace, helping them to protect people and so meet their health and safety obligations in this specialist area.
We are experienced in all matters that relate to the control of legionella and other waterborne pathogens delivering professional water safety risk assessments for legionella, pseudomonas and other waterborne pathogens. We offer water quality testing, independent compliance auditing, City & Guilds training and other risk management services that help keep staff and others safe.
If you would like to speak with one of our water safety specialists about managing your legionella and wider water safety risks call us today on 0330 223 36 86 or contact us here …
