• Online training login
t: 0330 223 36 86     e: [email protected]
Legionella Control International
  • Home
  • Services
  • Knowledge
  • Legionnaires
  • About
  • Contact
  • Click to open the search input field Click to open the search input field Search
  • Menu Menu
You are here: / Home / Knowledge / Guidance / What Are Biofilms?

What are Biofilms?

What Are Biofilms?A biofilm may sound like something you buy, perhaps to help in experiments with bacterial growth, but in reality the truth is somewhat different. A biofilm consists of a layer of microorganisms that adhere to one another. Together they form a protective layer that encapsulates colonies of bacteria inside the outer shell. Biofilms typically attach to hard surfaces and can be very difficult to remove once in place.

Bacterial biofilm

The microorganisms are generally bacterial in nature. Indeed, you may hear this referred to as a bacterial biofilm. Basically, the bacteria stick together (literally) and to whatever surface they are found on. The formation of the biofilm helps to protect the bacteria inside. Commonplace examples of biofilm include plaque sticking to teeth, the slimy coating found on rocks in streams and rivers, or the bacteria and gunk forming inside a pipe draining away from your sink.

There are three things that must be present for a biofilm to occur. They are:

  1. Moisture – this allows the bacteria to grow and spread.
  2. Bacteria – this could mean one species of bacteria or several, depending on the location and what is present.
  3. A surface – something for the bacteria to adhere to.

Biofilms will stick to lots of surfaces ranging from skin to water, a rock to a pipe, and metal to plastic. You name it – there is a good chance a biofilm can form on it, when the right elements are in place for this to happen.

Can biofilms cause health hazards?

The management and control of biofilms is very important in all walks of life. They can cause health hazards as they help to protect colonies of bacteria from lots of different treatments that would otherwise kill the individual or free floating bacteria. The biofilm acts as a very effective “hide-out” for bacteria that can be very difficult to remove.

Will a biofilm eventually disperse and disappear?

No. Think about what would happen if you decided not to brush your teeth for a day. The dental plaque in your mouth would start to build up, and you’d feel it as a layer or coating on your teeth. If you got up the next day, the plaque would not have disappeared. In fact, over time, it is likely to get worse – unless you (or a dentist) does something to remove it.

Managing Pseudomonas and Legionella bacteria

This is the case in every situation where a biofilm has formed. In some situations, a biofilm can present us with a potential health hazard. A good example is a situation where Pseudomonas or Legionella bacteria contaminates and spreads in a water system. The bacteria may be on the surface of the water, inside water pipes or somewhere else in the water system. If susceptible individuals come into contact with the bacteria contaminating the water, they could potentially fall ill as a result. This is why it is so important to manage and control the presence of biofilms, and ideally prevent them from occurring in the first place.

In this example, proper management and monitoring of both Pseudomonas and Legionella bacteria will prevent situations where people may succumb to infections including Legionnaire’s disease as a result of coming into contact with the bacteria.

Professional legionella risk assessment, training, testing and risk management support services

To find out more about our professional Legionella risk assessment, training, testing and other Legionella risk management support services call us today on 0330 223 36 86 or get in touch here … contact us

London Office
Kemp House
152 City Road
London EC1V 2NX
United Kingdom
Tel: +44 (0) 203 637 47 48

Manchester Office
Warren Bruce Court
Warren Bruce Road
Manchester M17 ILB
United Kingdom
Tel: +44 (0) 161 877 0586

Further reading

For additional information about legionella and Legionnaires; disease … here

Search Search

Expert resources…

  • Legionella & other pathogens
  • Regulatory compliance
  • Expert guidance
  • International
  • Legionnaires’ disease
  • Legionella training
  • Glossary of terms
  • FAQ
  • News

REVIEWS

4.8
Legionella Control International is rated 4.8 out of 5 stars (based on 182 customer reviews)
Read our reviews

Get in touch...

Legionella Control International
Warren Bruce Court
Warren Bruce Road
Manchester M17 1LB
United Kingdom

Manchester: +44 (0) 161 877 05 86
London: +44 (0) 203 637 47 48
Email: [email protected]

Legionella newsletter...

A simple and convenient way of keeping up to date with the latest Legionella news, new legislation, best practice, R&D and much more…

Useful downloads…

  • HSE ACOP L8 – Control of Legionella
  • HSG274 Part 1 – Evaporative Cooling
  • HSG274 Part 2 – Hot & Cold
  • HSG274 Part 3 – Other Risks
  • Positive Legionella Tests – What To Do?
  • HSG282 – Spa Pools
  • Legionnaires’ – Duty Holders Guide
  • Health & Safety – Care Homes
  • Scalding Risks – Health & Social Care
            © Copyright 2026 - Legionella Control International Ltd.
  • Link to X
  • Link to Facebook
  • Link to LinkedIn
  • Home
  • About
  • Contact
  • FAQ
  • Disclaimer
  • Privacy
  • Modern Slavery
  • Reviews
  • Sitemap
Link to: Legionella Logbook: Managing Legionella Bacteria Link to: Legionella Logbook: Managing Legionella Bacteria Legionella Logbook: Managing Legionella BacteriaLegionella Log Book - Managing the Risks from Legionella Bacteria Link to: City & Guilds Online Legionella Training Courses Link to: City & Guilds Online Legionella Training Courses City & Guilds Online Legionella TrainingCity & Guilds Online Legionella Training Courses
Scroll to top Scroll to top Scroll to top

This site uses cookies. By continuing to browse the site, you are agreeing to our use of cookies.

OKLearn more

Cookie and Privacy Settings



How we use cookies

We may request cookies to be set on your device. We use cookies to let us know when you visit our websites, how you interact with us, to enrich your user experience, and to customize your relationship with our website.

Click on the different category headings to find out more. You can also change some of your preferences. Note that blocking some types of cookies may impact your experience on our websites and the services we are able to offer.

Essential Website Cookies

These cookies are strictly necessary to provide you with services available through our website and to use some of its features.

Because these cookies are strictly necessary to deliver the website, refusing them will have impact how our site functions. You always can block or delete cookies by changing your browser settings and force blocking all cookies on this website. But this will always prompt you to accept/refuse cookies when revisiting our site.

We fully respect if you want to refuse cookies but to avoid asking you again and again kindly allow us to store a cookie for that. You are free to opt out any time or opt in for other cookies to get a better experience. If you refuse cookies we will remove all set cookies in our domain.

We provide you with a list of stored cookies on your computer in our domain so you can check what we stored. Due to security reasons we are not able to show or modify cookies from other domains. You can check these in your browser security settings.

Google Analytics Cookies

These cookies collect information that is used either in aggregate form to help us understand how our website is being used or how effective our marketing campaigns are, or to help us customize our website and application for you in order to enhance your experience.

If you do not want that we track your visit to our site you can disable tracking in your browser here:

Other external services

We also use different external services like Google Webfonts, Google Maps, and external Video providers. Since these providers may collect personal data like your IP address we allow you to block them here. Please be aware that this might heavily reduce the functionality and appearance of our site. Changes will take effect once you reload the page.

Google Webfont Settings:

Google Map Settings:

Google reCaptcha Settings:

Vimeo and Youtube video embeds:

Other cookies

The following cookies are also needed - You can choose if you want to allow them:

    Download our Legionella Risk Assessment Checklist for business owners, landlords, property managers and health and safety specialists and start managing your legionella risk today.