Legionella Risk Assessment

  • Risk Assessment
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Peninsula Team, Peninsula Team

(Last updated )

In this guide, we will discuss Legionella risk assessments, control measures you can implement, and the relevant Health & Safety legislation.

Your workplace will likely have several hazards you need to control or remove. These include invisible hazards - such as infectious bacteria. If you work with water systems, this is especially prevalent. This is because dangerous bacteria - such as Legionella - can spread.

Failure to control Legionella bacteria could have severe consequences for your business. For instance, staff or customers might become seriously ill. To avoid this happening, you must perform a Legionella risk assessment.

In this guide, we will discuss Legionella risk assessments, control measures you can implement, and the relevant Health & Safety legislation.

What is Legionella?

Legionella is a form of dangerous bacteria which mostly persists within natural water sources; such as rivers, lakes and reservoirs. But, it also occurs within artificial water systems - where there is water and conditions of creating water droplets.

This includes environments such as:

  • Hot and cold water systems.
  • Hot and cold water tanks.
  • Cooling towers.
  • Spa pools.
  • Jacuzzis and hot tubs.

How does Legionella bacteria survive?

Legionella bacteria needs three things to survive; the right temperature, nutrients, and stagnation. Put simply, it:

  • Thrives in temperatures between 20°C - 40°C.
  • Feeds off materials such as rust.
  • Is especially evident in infrequently used areas.

Failure to control Legionella in your workplace can have severe consequences. For example, your customers or staff could develop Legionnaires disease.

What is Legionnaires disease?

Legionnaires disease is a severe form of pneumonia, which can be contracted after inhaling tiny droplets of contaminated water containing Legionella. Whilst uncommon, it is highly serious and can be potentially fatal.

It can cause a variety of physical symptoms, such as a long-term cough. There is treatment available for the condition. For example, affected individuals might receive antibiotics, or even a machine to aid breathing. Other symptoms include:

  • Shortness of breath.
  • Chest pain or discomfort.
  • A high temperature.
  • Flu-like symptoms.

Regardless of the severity of the condition - or the treatment options available, you must remove or reduce the risk of Legionnaires disease occurring in your workplace.

What occupations are most at risk of spreading Legionella?

Several occupations are more at risk of spreading Legionella than others, for example, hair salon owners. Essentially, Legionella can occur in any workplace where water systems are present. This includes:

  • Dental and orthodontic surgeries.
  • Leisure centres with water systems, such as a spa or pools.
  • Hospitality settings, such as a restaurant or cafe.

Any workplace that operates water systems has a risk of Legionella bacteria growth. Which is why - if you own a business such as the above - you must perform a Legionella risk assessment.

What is a Legionella risk assessment?

A Legionella risk assessment is an evaluation of the risks posed by water systems - specifically used in domestic premises, buildings and commercial properties.

As part of Legionella control, property managers and employers conduct Legionella risk assessments. These assessments determine whether Legionella is present in your workplace. But, they can also advise on what control measures you must implement to reduce or remove the risk of harm.

How much does a Legionella risk assessment cost?

The cost of a Legionella risk assessment varies depending on the size and scale of your business. For example, if you own a small dental practice - the cost will be approximately £200.

Medium-to-larger sized enterprises will have an increased cost, beginning at £500. But, these are just estimates - for more information, request a quote from a water treatment company.

Is a Legionella assessment mandatory?

Yes, a Legionella risk assessment is mandatory in any premises that operate a water system. As advised by the UK Health and Safety at Work Act (1974), employers are responsible for the Health & Safety of their staff, and any visitors to their company.

Meaning, business owners must conduct a sufficient assessment of their work to identify any health hazards or substances hazardous to health. If your workplace operates water systems, then your risk assessment must check the risk of Legionella - as well as the likelihood of harm occurring.

Either way, when properly undertaken, a Legionella risk assessment will help you implement suitable precautions to mitigate the danger. Remember, if your workplace has five or more employees, it's a legal requirement for you to record your findings.

However, all businesses must be able to demonstrate how they manage Legionella risk - recording your risk assessment is simply the easiest way to do this.

Who can carry out a Legionella risk assessment?

Health & Safety law says you must appoint a 'Legionella responsible person' to carry out your Legionella risk assessment. This person will be in control of:

  • Ensuring your legal compliance.
  • Identifying Legionella hazards.
  • Assessing the risk of harm.
  • Implementing control measures to prevent harm.

The person you decide to appoint doesn't have to be a part of your key personnel. But they do have to be equipped to assess the risks of Legionella in a technically competent manner. For example, they might have had Legionella awareness training, or be familiar with conducting risk assessments.

Ultimately, these health regulations help to create a work environment where all staff are safe from harm.

What happens if you don't perform a Legionella risk assessment?

You could face severe consequences if you don't perform a Legionella risk assessment and your workplace has water systems.

First and foremost, you'll likely increase the risk of Legionella bacteria spreading. Which, if left untreated could cause adverse health effects, such as Legionnaires disease.

Additionally, you might have your legal non-compliance investigated by the Health and Safety Executive (HSE). As a result, you may face fines, legal proceedings, and even reputational damage.

How often should a Legionella risk assessment be reviewed?

The HSE's approved code of practice advises that employers perform risk assessments annually. But, depending on the situation, a Legionella risk assessment might need to be conducted more often.

For instance, the HSE also asks employers to conduct routine testing for Legionella quarterly. If your test reveals that the amount of Legionella in your water has changed, you should review your Legionella risk assessment.

This assessment should also be reviewed regularly if your workplace experiences significant changes. For example, if you hire more employees, or open another water facility.

How to do a Legionella risk assessment

There are several steps involved in a Legionella risk assessment. It's slightly different from a general risk assessment, as there's just one hazard you need to evaluate. But, you still must do everything you reasonably can to assess this risk properly, and comply with the relevant legislation.

Let's explore the steps in further detail:

Evaluate who is affected

The first step you should take in your Legionella risk assessment is to evaluate who is at risk of being affected by Legionella. For example, if these are younger members of staff, they'll have a low risk of contracting a severe type of Legionnaires disease.

However, if you employ older staff members, they'll have a higher risk level of being severely impacted by Legionella growth. Ensure your assessment also includes those with disabilities or any pregnant workers.

Assess both water systems

Next, you need to assess both the hot and cold water system. Depending on what system you use will affect the chance of Legionella risks. You need to confirm whether these are:

  • Mains fed, or;
  • From a water storage, or;
  • A combination of both.

If any part of your system collects water from storage, you'll have a higher risk of Legionella spreading throughout. This is because stagnant water is ideal for Legionella bacteria growth. If your water comes from storage, you'll need to work out what measures to implement to prevent Legionella from spreading.

Record water temperature

Now you've assessed the above, you need to record the temperature of your water systems. This is so you can ensure that their temperature won't enable the growth of Legionella bacteria.

Your hot water cylinder and systems need to be above 50°C, and your cold water systems need to be under 20°C. The only exception is if you already have secondary disinfection systems in place.

Identify and assess potential risks

After recording the temperature of your water systems, you can begin identifying the risks within. For example, you might need to assess the risk that redundant pipework in your cold water tank poses.

Or you might need to work out how to properly maintain certain equipment, such as any thermostatic mixing valves. Either way, it's important to evaluate every aspect of your water system. Otherwise, you might fail to identify risk - which could cause harm to staff or visitors.

Implement control measures

Once you've identified the risks within your water systems, you must prevent the risk from occurring, or remove it completely. If you can't eradicate the risk, then you must control it instead.

For example, if your workplace has evaporative cooling systems, you'll have a higher risk of Legionella growth. This is because the water used for cooling becomes stagnant in the process. So, to control the risk, you should appoint someone to regularly monitor and maintain the system.

Review your risk assessment regularly

Now you've finished your risk assessment, you should record the results. This is one of your legal obligations if your workplace employs five or more people. But it's also useful as a point of reference for future assessments.

If you operate more complex systems, it's worth contacting the Legionella Control Association. They can offer further advice on assessing your workplace for Legionella, as well as what control measures you should implement.

Get expert advice on your Legionella risk assessment from Peninsula

You must ensure you perform a Legionella risk assessment if you work with water systems. So if you ignore your legal responsibilities to maintain water quality and prevent the spread of waterborne pathogens, your staff or customers could become severely ill.

As a result, you could face claims to an employment tribunal. Which will likely result in financial and reputational damage.

Peninsula offers expert advice on your legal duties when it comes to Legionella risk assessments and Legionella testing. Our teams provide 24/7 Health & Safety advice which is available 365 days a year. We take care of everything when you work with our Health & Safety experts.

Want to find out more? Contact us on 0800 028 2420 and book a free consultation with a Health & Safety consultant today.



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