June 28, 2019
COMMUNIQUÉ
Service Wide Committee on Occupational Health and Safety
With spring upon us and the temperatures slowly on the rise, custodians will soon be switching over the operations of the heating, ventilation and air conditioning (HVAC) systems in buildings from a heating to cooling mode. As part of the switch over from a heating to cooling mode, seasonally operated cooling towers will be placed into operation while the operation of year-round cooling towers will continue.
This National Joint Council (NJC) communiqué serves as a reminder for the need to have a plan to control Legionella in Heating, Ventilation and Air Conditioning (HVAC) systems to ensure workers’ safety and demonstrate due diligence in ensuring Employers’ duties related to the health and safety of employees and visitors are fulfilled under the Canada Labour Code Part II and the NJC Occupational Health and Safety Directive, which enhances the Canada Labour Code Part II for the Core Public Administration (and other departments/agencies following this directive).[1]
Employers shall ensure that Policy Committees, Work Place Committees and Health and Safety Representatives, are informed of any updates to custodial buildings’ Legionella management plan and are sharing all testing results indicating a need for unscheduled maintenance activities to control Legionella growth. This is done to inform that cooling tower water system shut-down for maintenance and disinfection may affect, depending on climatic conditions during this period, the indoor comfort conditions.
It is also important that Employers provide all testing results when requested by Policy Committees, Work Place Committees or Health and Safety Representatives. Sharing testing results has the benefit of informing recipients but also has the potential to cause undue alarm. This is why proper context must be provided on what the results mean in terms of risk and maintenance actions. Please ensure that you know and understand your role for the management of Legionella.
For minimum design, installation, operation, maintenance and validation testing frequencies and procedures for Legionella susceptible systems, we recommend you consult the Public Services and Procurement Canada (PSPC) document:
The SWOHS Committee recommends that the minimum frequency and testing type for a Cooling Tower Bacterial Test Protocol be:
- Weekly – Dipslide tests
- Monthly – Legionella culture tests
- 24 hours following completion of start‐up, cleaning, or disinfection – quantitative polymerase chain reaction (qPCR) tests.
These minimum testing types and frequencies are important because legionella bacteria can grow rapidly given favorable growth conditions.
A chart, of recommended Cooling Tower Bacterial Test Protocols, is Figure 1, page 59 of the MD 15161 – 2013, Control of Legionella in Mechanical Systems: Standard for Building Owners, Design Professionals, and Maintenance Personnel.
In addition, the Legionella bacteria control management program-1 Facility checklist (LBCMP‐1) is found at Appendix E, page 64 of MD 15161 – 2013, Control of Legionella in Mechanical Systems: Standard for Building Owners, Design Professionals, and Maintenance Personnel. This helpful checklist can be used to ensure compliance and a copy of the completed checklist, with dates, should be provided to the Workplace Committee(s).
For questions or assistance in implementing a Legionella program in your organization, please consult your PSPC Real Property Services Account Executive.
Appendix A
Copied from the following link: Public Health Agency of Canada
Legionella
What is Legionella?
Legionella are bacteria that live in water that can cause two types of illness in humans: Legionnaires’ disease and Pontiac fever.
Legionnaires’ disease is a serious respiratory illness that results in pneumonia. The name Legionnaires’ disease comes from an outbreak of pneumonia that killed 29 people at an American Legion Convention in Philadelphia in 1976.
In Canada, the average number of reported cases of Legionnaires’ disease is generally less than 100 per year. However the actual number of cases is thought to be much higher, as many people with pneumonia may not be tested for infection with Legionella.
Pontiac fever is a milder illness causing flu-like symptoms but not pneumonia and was first described in Pontiac, Michigan in the early 1970s. People with Pontiac fever generally recover in two to five days without treatment.
How common is Legionnaires’ Disease?
Legionnaires’ disease occurs throughout North America, as well as in Asia, Africa, Australia, Europe and South America. Sporadic cases and outbreaks most commonly occur in summer and autumn, although cases can occur throughout the year.
Legionnaires’ disease is not a common disease, and the risk of getting it is generally quite low. Cases of Legionnaire’s disease may be difficult to detect because very few of the people exposed to the bacteria get infected. For instance, if 100 people are exposed to Legionella, fewer than 5 of them will get Legionnaire’s disease. On the other hand, in an epidemic of Pontiac fever, if 100 people are exposed, 95 of them are likely to become sick.
What are the symptoms of Legionnaires’ disease?
In addition to pneumonia, symptoms can include fever, cough, muscle pain and headache. Symptoms start within 2 to 14 days of infection, and can last for several months.
If symptoms persist, consult your health care provider. Most cases can be treated successfully with antibiotics. Effectiveness of the treatment varies with age and overall health, and can also depend on how quickly the person receives the right medical treatment.
Who’s at risk for Legionnaires’ disease?
The following people are at greater risk of developing the disease:
- individuals over 40 years of age;
- smokers;
- alcoholics;
- people with chronic lung or kidney disease;
- people with diabetes; and
- people with weakened immune systems due to conditions such as cancer or an organ transplant.
People in certain occupations, such as those who do maintenance work on large air-conditioning systems, may also be at increased risk of exposure to Legionella bacteria.
Generally, more men than women contract Legionnaires’ disease. It is uncommon for people younger than 20 years of age to get Legionnaires’ disease.
How do you get Legionnaires’ Disease?
Legionella bacteria are found in natural water sources such as lakes, rivers, ponds, and streams generally at levels that are too low to cause disease in people. Cases of Legionnaires’ disease have occurred in many different settings, including homes, commercial buildings, spas, cruise ships and health care facilities. Legionnaires’ disease cannot be spread from one person to another. The number of bacteria determines the risk for humans.
Certain conditions that may be present in buildings and homes promote the growth of the bacteria. These include stagnant water, warm water temperatures (especially between 20°C and 50°C) and the presence of biofilm, scale and sediment. These conditions may be found in:
- cooling towers, such as those used with the air conditioning systems of large buildings;
- whirlpool bathtubs, hot tubs and public spas;
- plumbing systems (including water heaters, faucets and showers) either in the home or in larger buildings; and
- humidifiers.
When water contaminated with larger quantities of Legionella is released into air in the form of droplets or mist, people may be exposed to the bacteria by breathing in the contaminated air.
Cooling towers can be a good environment for Legionella to grow and these towers can release large quantities of water droplets to the air. This is why they are often linked to outbreaks of Legionnaires’ disease. Droplets with high concentrations of Legionella may then enter a building if, for example, the ventilation system intake is near the cooling tower. In some outbreaks however, Legionella bacteria from cooling towers appear to have survived and spread in the air over a distance of several kilometers. In these outbreaks, cases were not linked to a particular building or public space.
How can I reduce my risk?
The risk of getting Legionnaires’ disease is generally quite low.
In your home, you can reduce the risks through proper maintenance of all mist-producing devices, such as shower heads, hot tubs, whirlpool bathtubs, and humidifiers. Make sure you clean and disinfect these devices regularly according to manufacturer directions. Keeping your home water heater at a suitable temperature (a minimum of 60°C) will also help prevent the growth of Legionella. However, to reduce the risk of scalding, it is important that temperature of the water be no higher than 49°C at the tap. A qualified plumber should be contacted to install mixing valves to control the tap water temperature.
[1] Many workplaces under federal jurisdiction use water-cooled industrial and commercial air conditioners. The water contained in these units and in the cooling towers can contain Legionella bacteria and is an environment where these bacteria can grow under certain conditions. Legionella bacteria grows best at warm temperatures: it grows vigorously between 25°C and 45°C (temperatures above 50°C will start to kill the bacteria but temperatures at 60°C will kill the bacteria at a faster rate. Therefore domestic water heathers should be maintained at 60°C.). The bacteria can be transmitted to people through inhaled water droplets.
Legionnaires' disease is a severe form of pneumonia or lung inflammation usually caused by the Legionella bacterium. Most people get Legionnaires' disease from inhaling the bacteria. The most susceptible people are the elderly, smokers, and those with weakened immune systems. The disease cannot be transmitted from one person to another. The most common symptoms include: fever, chills and a cough. Some people may also have a muscle aches, headaches, tiredness, loss of appetite, loss of coordination, chest pain, or diarrhea and vomiting.
For more information on Legionella bacteria and its associated infections, please see Public Health Agency of Canada information on Legionella (Content also available in Appendix A of this document).