Legionnaires’ disease is a severe form of pneumonia and can be deadly. In 2017 alone, 693 cases of Legionnaires’ disease were reported/notified – a 40% increase on 2016’s figure.
Who is at risk?
When it comes to Legionnaires’ disease, everyone’s susceptible. That said though, individuals who fall into any of the below categories may be at greater risk of contracting it:
- People who’re 45 years old or above;
- Smokers and heavy drinkers;
- Individuals with diabetes, lung and heart disease;
- People suffering from chronic respiratory or kidney disease; or
- Anyone who has an impaired immune system.
- Men are also 3 times more susceptible than women.
Where do you find Legionella bacteria?
Legionella bacteria can be found in natural water supplies, like rivers, lakes, reservoirs and ponds, but usually in low numbers. Conditions are rarely favourable in these environments for transmission of the bacteria, and so natural water sources aren’t usually associated with Legionnaires’ disease.
More commonly, Legionnaires’ disease is linked to purpose-built water systems such as cooling towers, spa pools, hydrotherapy baths and hot and cold water systems – to name just a few, where temperatures are high enough to support bacteria growth and the network is insufficiently managed.
The optimum temperature for Legionella growth and multiplication is between 20-45°C. Anything lower than 20°C is too cool for the bacteria to activate, and anything above 60°C is too hot for it to survive. Legionella bacteria also need nutrients like rust, sludge, scale and biofilms, which provide harbourage and food.
How is Legionnaires’ disease caught?
Legionnaires’ disease is caught by simply breathing in small droplets of water that contain Legionella particles. These small droplets are also known as aerosols.
Employees, visitors, customers, clients and anyone else in your premises run the risk of being exposed to contaminated water, and so it’s essential you have appropriate measures in place.
As an employer, it’s your responsibility to control any risks associated with Legionella exposure. To meet these, there’s a five-step process to follow – we’ll delve into each of these now.
1. Identifying and assessing risks
A competent person must carry out a thorough risk assessment to assess whether any of your water systems are likely to pose a Legionella hazard.
During the risk assessment, you should look out for things like:
- Does the water temperature sit between 20-45°C in any part of the water system(s)?
- Is water stored and/or re-circulated in the system?
- Are nutrients present for the bacteria to feed off?
- Are any employees, visitors, residents, etc. at greater risk due to their age, habits or health condition?
2. Manage the identified risks
Once risks have been identified, it’s time to manage them. Prioritise the risks in terms of how harmful they could be, and consider who will be affected – remember, it’s not just employees and residents; visitors, customers, inspectors and suppliers, for example, could be impacted too.
3. Prevent or control the risk
Your first port of call should be preventing any Legionella risks. For example, if you’re currently using a wet cooling tower which has the potential to produce water droplets contaminated with Legionella bacteria, could you switch to a dry air-cooled system?
Essentially, the aim of this exercise is to ensure all your water systems operate in a way that isn’t conducive to the growth and spread of Legionella.
In the event that you identify a risk that can’t be prevented, you must put appropriate measures in place to control the risk as best you can – if you need a hand working out what these are, get in touch with our Health & Safety experts.
4. Accurate records
If you’ve got five or more employees on your books, you’re legally required to keep a written record of your risk assessment. Your records should include information like:
- The name of the individual who conducted the risk assessment;
- Any significant findings uncovered during the assessment;
- What measures have been put in place to prevent or control the risks;
- An overview of the condition of your water systems; and
- The results of any water system inspections, tests or checks.
NB: a written risk assessment isn’t a legal requirement if you have fewer than five employees but it’s still good practice to keep a written record for future reference.
The management process of assessing and continually monitoring your water functions should be completed by a competent person – this could be in the form of a third-party specialist.
5. Other duties
In addition to steps one to four, there are a couple of other responsibilities to be aware of:
Notification of Cooling Towers and Evaporative Condensers Regulations 1992: if you have a cooling tower or evaporative condenser on your site, you must let your local authority know where it’s situated.
Reporting of Injuries, Diseases and Dangerous Occurrences Regulations (RIDDOR): if you have an employee who’s been working on cooling towers and/or hot and cold water systems and you suspect they may have contracted Legionella, you must report it.
How to prevent Legionnaires’ disease
The easiest way to prevent Legionnaires’ disease is by implementing measures that allow you to appropriately regulate your water temperature.
As we touched on earlier, the optimum temperature for Legionella growth is between 20-45°C. With this in mind, you should ensure:
- Hot water contained in hot water cylinders is at least 60°C;
- Hot water is distributed at a minimum of 50°C; and
- Cold water is stored and distributed below 20°C.
- A nominated competent person should be in charge of regularly monitoring your water temperature, flushing out little used outlets, and for making arrangements for your water system to be thoroughly inspected, cleaned and disinfected if necessary.
We’re here to help
When it comes to Legionella, there can be a lot to get your head around – which is where we come in. Our safety experts can identify any legionella risks within your business, conduct a legionella risk assessment and provide advice on simple in-house measures to reduce the risk.