Legionella risk assessment

Guardian Legionella and Safeguard Pest Control are both part of the Orkin Global family, with Safeguard being the UKā€™s flagship pest control company and Guardian being the UKā€™s flagship legionella company.

Guardian was established in July 2004, in Lincoln, operating alongside the pest control division. Since then, Guardian has grown to become a national legionella provider across many sectors such as healthcare, facilities, schools, funeral directors, care homes, commercial buildings and many more. Guardian Legionella offer a professional, prompt, and reliable service in all aspects of legionella, from legionella risk assessments to tank cleaning and disinfection.

Our emphasis, as with all Orkinā€™s family of brands; is on serving the customer to the best of our ability and building a long term relationship of mutual trust and understanding with a strong communication platform for all our clients.

We have service technicians local to Lincolnshire, Yorkshire, Scotland, the South and the North West, London, West Midlands and beyond, so our customers can continue to receive the local service from a technician who is familiar with the region; whilst offering a national service to all clients.

Our experienced office staff are available from 9.00am to 5.00pm Monday to Friday to answer any customer queries and give advice, please see below some of the services we specialise in:

  • Legionella Risk Assessments
  • Legionella Control Schemes
  • Water Monitoring
  • Tank Cleaning & Disinfection
  • TMV Servicing
  • Legionella Sampling
  • Disinfection of Hot & Cot Water Systems


  • What is Legionella?

    In 1976, there was an outbreak of the disease in Philadelphia amongst people attending a convention of the American Legion and 29 people, mostly men, died. The disease identified was named Legionnairesā€™ disease. Also know as Legionellosis, but Legionnairesā€™ Disease is the more common name. The most common form of transmission of Legionella is inhalation of contaminated aerosols produced in conjunction with water sprays, jets or mists. Infection can also occur by aspiration of contaminated water or ice, particularly in susceptible hospital patients. Legionnairesā€™ disease has an incubation period of 2 to 10 days (but up to 16 days has been recorded in some outbreaks).

  • Where does Legionella come from?

    Legionella bacteria are widespread in natural water including rivers, lakes, and ponds. It can also be found in soil and compost. However, the conditions are rarely right for people to catch the disease from these sources. Most outbreaks occur from exposure of Legionella bacteria in purpose built water systems including cooling towers, evaporative condensers, hot and cold water systems and spa pools used in all sorts of premises (work and domestic).

  • How is Legionnaireā€™s disease contracted?

    People contractĀ Legionnaires’ disease by inhaling small droplets of water (aerosols), suspended in the air, containing the bacteria. Certain conditions increase the risk from legionella if:

    • the water temperature in all or some parts of the system may be between 20-45 Ā°C, which is suitable for growth
    • it is possible for breathable water droplets to be created and dispersed eg aerosol created by a cooling tower, or water outlets like showers
    • water is stored and/or re-circulated
    • there are deposits that can support bacterial growth providing a source of nutrients for the organism eg rust, sludge, scale, organic matter and biofilms

  • What diseases are caused by Legionella?

    Legionellosis is a collective term for diseases caused by legionella bacteria including the most serious Legionnaires’ disease, as well as the similar but less serious conditions of Pontiac fever and Lochgoilhead fever. Legionnaires’ disease is a potentially fatal form of pneumonia and everyone is susceptible to infection. The risk increases with age but some people are at higher risk including:

    • people over 45 years of age
    • smokers and heavy drinkers
    • people suffering from chronic respiratory or kidney disease
    • diabetes, lung and heart disease
    • anyone with an impaired immune system

  • Do I need a Legionella risk assessment?

    Carrying out a legionella risk assessment and ensuring it remains up to date is required under health and safety law and is a key duty when managing the risk of exposure to legionella bacteria.

    Legionnairesā€™ disease: The control of legionella bacteria in water systems. Approved Code of Practice gives specific information on the health and safety law that applies. In brief, general duties under the Health and Safety at Work etc Act 1974 (the HSW Act) extend to risks from legionella bacteria, which may arise from work activities. The Management of Health and Safety at Work Regulations 1999 provide a broad framework for controlling health and safety at work. More specifically, the Control of Substances Hazardous to Health Regulations 2002 (COSHH) provide a framework of duties designed to assess, prevent or control the risks from hazardous substances, including biological agents such as legionella, and take suitable precautions.

    The essential elements of COSHH are:

    • risk assessment;
    • prevention of exposure or substitution with a less hazardous substance if this is possible, or substitute a process or method with a less hazardous one;
    • control of exposure where prevention or substitution is not reasonably practicable;
    • maintenance, examination and testing of control measures, eg automatic dosing equipment for delivery of biocides and other treatment chemicals;
    • provision of information, instruction and training for employees;
    • health surveillance of employees (where appropriate, and if there are valid
    • techniques for detecting indications of disease) where exposure may result in
    • an identifiable disease or adverse health effect.

    Under general health and safety law, dutyholders including employers or those in control of premises, must ensure the health and safety of their employees or others who may be affected by their undertaking. They must take suitable precautions to prevent or control the risk of exposure to legionella. They also need to either understand, or appoint somebody competent who knows how to identify and assess sources of risk, manage those risks, prevent or control any risks, keep records and carry out any other legal duties they may have.

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Legionella Risk Assessments

Our qualified risk assessors will carry out a detailed assessment of your premises, which will ensure compliance with the approved code of practice ACOP L8.

The risk assessment will provide:

  • Identification and assessment of the source of any risk of legionella.
  • A written scheme (course of action), to prevent, minimise and control the risk.

Our aim when carrying out a legionella risk assessment is to ensure you understand your water systems and the risks posed to staff and the public. Upon completion, we will provide advice on the best course of action to ensure the risk of legionella proliferation is prevented or minimised.

Duty holders should arrange to review the assessment regularly and specifically when there is reason to suspect it is no longer valid. An indication of when to review the assessment and what to consider should be recorded and this may result from:

  • A change to the water system or its use
  • A change to the use of the building where the system is installed
  • New information available about risks or control measures
  • The results of checks indicating that control measures are no longer effective
  • Changes to key personnel
  • A case of Legionnairesā€™ disease/legionellosis associated with the system

Whilst failure to comply to any part of the ACOP is not in itself an offence, that failure may be used in criminal proceedings in a court of law in contravention to HSWA 1974, COSHH 2002 and MHSWA 1999.

How Legionella Affects Your Business

  • All employers with five or more employees must commission a legionella risk assessment on their water systems
  • Failure to comply with the legal requirements surrounding legionella can result in prosecution.
  • Legionella causes Legionnairesā€™ disease, a potentially fatal form of pneumonia. Failure to properly manage your water systems may risks your life or that of your staff or clients.
  • If the Health and Safety at Work Act 1974 applies to your business premises, then you are required by law to commission a legionella risk assessment on its hot and cold-water systems.

Comprehensive landlord Legionella risk assessments with Guardian Legionella

Guardian Legionella provides businesses and landlords with fully comprehensive legionella risk assessments, and legionella training courses. Our legionella risk assessments swiftly identify whether legionella bacteria are present in man-made water systems to ensure your staff, residents and visitorsā€™ health and safety is not at risk. Our risk assessments are designed to be minimally-invasive, allowing you and your business to continue to operate normally.

Legionella risk assessments provide landlords with a starting point for actions and risks to complete, ensuring their property is compliant and controlled with the threat of legionella bacteria and Legionnairesā€™ disease.

However, it is important to prepare for your assessment, by having all the relevant information to hand to ensure the assessment can be carried out efficiently.

Your legal responsibilities as a landlord
As a landlord, you do have legal requirements and responsibilities regarding the safety and welfare of your tenants, staff, and site visitors. These legal requirements are all covered in HSEā€™s L8 Code of Practice document, as well as our article on legionella testing.

Simply put, as a landlord of a domestic or residential property, it is your duty to assess the risk from exposure to legionella to ensure the safety of your occupants.

It goes onto state that although it is a legal duty for landlords to assess and control the risk of exposure to legionella, the health and safety law ā€œdoes not require landlords to produce or obtain, nor does HSE recognise, a Legionnairesā€™ testing certificateā€.