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Do I need a legionella risk assessment?


What exactly is Legionnaires’ Disease?

For any businesses not in the know, Legionnaires’ Disease is a waterborne and bacterially transmitted health condition, whereby the physical embodiment of Legionella itself is the bacterium of the genus legionella. Essentially, Legionnaires’ manifests in water systems that are home to either/stored/re-circulated water (in all or some part of said system) at temperatures of between 20 – 45 degree centigrade – and which actively encourages an increase in the bacteria present. These immediate environments which could, potentially give rise to legionella if not identified and treated, can surface in various industries and commercial sectors. What’s more, legionella can harvest and go on to thrive on a number of hosts. Think deposits often discovered within water supplies, including rust, sludge, scale and organic matter. Health problems really come to the fore in the event of subsequent water droplets being produced and dispersed, with legionella then being transferred from this initially contained area; bringing with it the onset of illness in those affected, typically by means of otherwise unsuspecting inhalation. It’s also worth noting that people exposed to legionella could see their susceptibility to infection significantly increased based on an individual’s age, an underlying illness and/or a weakened immune system.

<Learn more about the risks associated with legionella bacteria>

In what type of typical workplace eventualities might Legionella present?

With this in mind, it’s not difficult to understand how employees, contractors and visitors to a range of businesses may then find themselves unwittingly placed at risk by exposure to the bacteria. In fact, under closer scrutiny there are any number of situations - and/or employee/third party-facilitated installations/plants/equipment - which could result in people inadvertently contracting Legionnaires’ Disease while on work premises. Like for example those who are exposed to ultrasonic spray humidifiers/water misting systems, air washers, wet, particle and trivial gas scrubbers and water softeners. Elsewhere, emergency showers, eyebaths and face wash fountains, sprinkler and hose reel systems and spa/whirlpool baths all require habitual monitoring and HSE compliance, to minimise opportunities for legionella to take hold. Meanwhile the likes of horticultural misting systems, vehicle washers, fountains and decorative water features, industrial effluent treatment plants and powered dental equipment are all strictly subject to government-instilled/HSE-empowered Legionella-combating compliance for good reason.

Additional installations, equipment and consumer products which fall into this legionella risk category include non-disposable nebulisers used for respiratory therapy, irrigation systems, fire, dust and odour-suppression systems, paint spray preparation equipment and tunnel pasteurisers. Many of the systems abovementioned operate at - or beyond - ambient temperatures, or conversely are susceptible to acknowledged thermal increase during normal procedural operation; and tend to be noted in the same breath as evaporative cooling systems and hot and cold water systems.

Find out more about other risk systems you may have on site.

So, does my business need to perform a Legionella Risk Assessment?

As a business owner the simple answer to this question is, yes. It’s both your prerogative and moreover, responsibility to ensure that premises provide a risk-free environment, and specifically in terms of diminishing the threat of contacting Legionnaires’ Disease. Ostensibly this means adhering to the protocol, practice and application of a far-reaching legionella risk assessment. Yet it also means being au fait with procedures beforehand. By flouting valid risk assessments, negligent business operators are perceivably failing to prevent the possibility of legionella manifestation.

As it currently stands HSE laws decree that responsible individuals have a duty of care which envelops the provision of health and safety assurances regarding employees (and third parties) when on business premises. Ergo dutyholders are legally obliged to take suitable precautions to both actively prevent and/or control the threat of individuals being exposed to legionella. It’s also within their remit to manage this vital aspect of disease control themselves, or alternatively task a competent/qualified other (with experience of identifying and assessing sources of risk) with the prevention/management of legionella risks. Together with maintaining key records and documentation and to routinely perform any other pre-requisitional legal duties, those in possession of the relevant competence, knowledge and expertise must be appointed – internally or externally – to oversee all issues of this nature.

Want to learn more? Read the facilities manager's guide to legionella risk  assessments >

Can you describe the recognizable form and function of a Legionella Risk Assessment take?

Businesses have fundamental requirements to be legally compliant when it comes to identification/assessment of potential legionella risks; whether that’s threats posed by exposure to legionella from the hot and cold water system, or any work historically connected to it. At the core of any legionella risk assessment carried out, key aspects of the operation of water systems in situ will be addressed. Whoever conducts an externally-instructed risk assessment should seek consultation with the site personnel responsible for the governance of the systems and ascertain existing operational practice methodology and application. In effect, such dialogue would naturally embrace the commissioning, decommissioning, periods of operation, maintenance, treatment and subsequent management of each individual aspect of operation, and will ultimately necessitate review, so as to ensure site procedures are being strictly adhered to and accountability is clear.

It’s the job of the designated dutyholder to manage risks and effectively troubleshoot. The buck primarily stop with the dutyholder who – courtesy of their position – should be proficiently equipped with the skill set required to identify if and when company water systems are likely to create a risk from exposure to legionella bacteria, by qualifying/quantifying if the water stored - or re-circulated - as part of a system remains uncompromised.

Want to learn more? Read our free legionella compliance checklist.

Principal breakdown of  risk assessment stratagem

The following affords you a glimpse as to just how a risk assessment is carried out, by virtue of encompassing the mechanical, operational, chemical and management aspects more normally associated with both hot and cold water systems. Ordinarily, the nucleus of key legionella risk assessments would logistically revolve around a site survey, whereby focus would be centred round a business’ water systems; with criteria as follows;

  • Management responsibilities in place - including the name of a competent individual (management personnel) empowered to play an active role in, and safeguard any legionella risk, along with a fulsome description of a company’s system.
  • Assessment of competence of those directly associated with risk management protocol, procedure and implementation
  • Identification of roles and responsibilities (to include employees, contractors and consultants)
  • Flag up any potential source of legionella risk
  • Establish if any controls exist to control risks
  • Scrutinise current monitoring, inspection and maintenance procedures
  • Establish that consideration has been given to removing the risk by ‘substitution or elimination’
  • Review the scope of the assessment (i.e, the details and entirety of the plant/installation coverage)
  • Ensure that arrangements are in place to systematically review risk assessment on a timely basis
  • Assess validity of schematic diagram (inc all parts of the system where water may be used or stored)
  • System design details (inc asset register of all associated plant, pumps, strainers, outlets and other relevant items)
  • Assess potential for water system to become contaminated with legionella
  • Details of any water pre-treatment process
  • Gage potential for legionella to grow within the system and effectiveness of control measures
  • Evaluate chemical and physical water treatment measures
  • Analyse infection and cleaning practice
  • Appraise remedial work and maintenance
  • Determine evidence of corrective actions being implemented
  • Be privy to evidence of proactive management and follow-up of previous assessment recommendations
  • Seek evidence of the competence of those involved in control and monitoring activities

legionella risk assessment free guide download


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