Glossary

Note: some words can be defined differently depending on the field, sector, or region. Definitions here are based on the way words are used in this resource.

Ableism – Discrimination or bias against disabled people.

Accessibility – Being able to use or participate in programs, services, devices and the environment without barriers. See: barrier, conflicting access needs

Accommodation – A change or adjustment made to create or improve accessibility for a person or group.

Aerosol – A suspension of particles in the air or another gas (e.g., fog, dust, infectious respiratory particles). See: particle (particulate matter)

Airborne illness – An illness that can spread by aerosols (infectious respiratory particles), which an infected person breathes out and other people can breathe in. Airborne illnesses like measles, tuberculosis, COVID-19, RSV, or influenza can waft around like smoke, travelling long distances and potentially remaining in the air for hours, especially indoors.^{Footnote 230}

Air changes per hour (ACH) – The number of times the air in a space is removed and replaced in an hour, for example by the building's HVAC system. See: HVAC, ventilation

ASHRAE – The American Society of Heating, Refrigerating and Air-Conditioning Engineers; among other things, ASHRAE creates international standards for indoor air quality. See: standard

Asymptomatic – Being sick without obvious symptoms. Asymptomatic transmission refers to cases where someone infects another person or people with an illness when they aren't showing symptoms.

Barrier – Something that stops individuals or groups from being able to access something, or from being able to participate fully and equally. See: accessibility, ableism

CADR – Clean Air Delivery Rate, a measurement of a portable air purifier’s ability to clean the air of specific particle sizes. CADR is expressed as volume of air per unit of time (e.g., cubic feet per minute or CFM).^{Footnote 231}

Cleaning – The process of physically removing most germs, dirt, and impurities from objects and surfaces (e.g., by washing with soap and water). See: disinfection, sanitization

CO₂ – Carbon dioxide, a colourless gas that people breathe out. Higher levels of CO₂ can indicate insufficient fresh air indoors, and cause health issues.

Conflicting access needs – When different access needs contradict one another (e.g., one person needs bright lighting to see, but another person has light sensitivity).

CSA – CSA Group, previously the Canadian Standards Association. An organization that develops technical standards, provides training and advice, and certifies some health & safety equipment (like respirators). See: respirator, standards

Determinants of health – Personal, social, economic, and environmental factors that influence health outcomes. Commercial determinants of health are the way companies’ actions (or inactions) affect people's health. Social determinants of health relate to a person’s place in society (e.g., job, education, income, food or healthcare access, experiences of discrimination and generational trauma). Social determinants of health often create disparities for members of marginalized communities, including but not limited to Indigenous, Black, racialized, 2S/LGBTQIA+, and disabled people.

Disinfection – The process of eliminating all/almost all germs on surfaces by using a registered disinfecting product. See: cleaning, sanitization

Dysautonomia – Incongruent responses from the autonomic nervous system, such as racing heart rate when resting, increased blood pressure at rest, or trouble breathing or digesting.

Dysphonia – A change in vocal quality, including symptoms like hoarseness or difficulty speaking and/or singing.

Filtration – The act of passing air, water, or another fluid through a porous material (a filter) to strain out particles. See: HEPA, MERV, particle (particulate matter)

Fit test – A test to check that a respirator provides good protection (e.g., fits the face, doesn't leak). Generally required as part of a full workplace respiratory protection program, but not required for wearing respirators as source control or in the community.^{Footnote 232} Even a non-fit-tested respirator still provides far more protection than a surgical mask.^{Footnote 233} See: source control

Fomite – An object whose surfaces can collect germs that can spread illness. Some diseases spread easily through fomites (e.g., norovirus), in contrast to others that spread primarily through the air (e.g., measles, tuberculosis, COVID-19).

Hazard – A source of potential harm or damage.

HEPA – High Efficiency Particulate Air, an efficiency standard for air filters. HEPA filters remove at least 99.97% of very tiny particles (e.g., dust, mould, pollen, bacteria, viruses). See: filtration

HVAC – Heating, ventilation, and air-conditioning system. A building system that helps regulate temperature and circulate air (e.g., through air ducts). See: ventilation, filtration

Immunocompromised – Having a weakened immune system, for example due to a medical condition or medication.

Immuno-inclusivity – A new field of study and practice at the intersection of health & safety and accessibility. Inclusion of people with diverse immune systems, and practices protecting everyone’s current and future immune health.

Informed substitution – The practice of replacing possible hazards (such as hazardous chemicals) with alternatives known to be less toxic or non-toxic.

Long COVID – An umbrella term for symptoms and health damage that can arise following a COVID-19 infection. See: occupational disease

Mask – An umbrella term for a variety of face coverings meant to reduce the spread of illness by blocking germs that the wearer inhales or exhales. Different types of masks have different levels of effectiveness. See: PPE, respirator, source control, surgical mask

MERV – Minimum Efficiency Reporting Value. A scale that rates how well a filter can capture particles. MERV values range from 1-16; higher rated filters are more effective at particle removal. See: filtration

NAAT – Nucleic acid amplification test. An umbrella term for molecular tests that can identify diseases (or other things) very accurately by detecting their genetic material. PCR tests are one type of NAAT test, but there are also an increasing number of rapid NAAT tests that can be used at home. See: PCR test

N95 – A type of respirator approved by the US National Institute for Occupational Safety and Health (NIOSH) to filter 95% or more of airborne particles. The term is also used informally to refer to similar masks from countries other than the US (e.g., a CAN95 from Canada or a KN95 from China). See: respirator

Occupational disease – A work-related health condition or disorder.

OHS – Occupational health & safety, the field of protecting workers from hazards.

Pandemic – A worldwide or multi-region epidemic (rapid spread of illness) from an infectious disease, often characterized by surges rather than stable rates.

PAPR – Powered air-purifying respirator. A type of respiratory protective device with a fan to move air through the filter; often looks like a hood, helmet, or clear face shield. See: respirator

Particle (particulate matter) – A solid or liquid blob that can be airborne (e.g., dust, mist, smoke, pollen, spores, bioaerosols). See: aerosol, PM_2.5

Pathogen – A living organism that can cause disease (e.g., bacteria, viruses, fungi, mould).

PCR test – Polymerase chain reaction test. A lab test designed to amplify and recognize a specific type of genetic material. Often considered the gold standard to detect and diagnose viruses like SARS-CoV-2. See: NAAT

PM_2.5 – Fine particulate matter under 2.5 micrometers in size. Generated by many things, from car exhaust to wildfire smoke, PM_2.5 is a hazard that can travel deep into the lungs and enter the bloodstream. There is no safe level of PM_2.5.^{Footnote 234} See: particle (particulate matter)

Post-exertional malaise (PEM) – New or worsened symptoms after even minor exertion, often presenting 24 or more hours or more later. Physical activity, cognitive activity, and sensory input can all trigger PEM, which can last for days, weeks, or much longer.

PPE – Personal protective equipment. Clothing or gear to protect the wearer from harm. Respirators are often referred to as PPE, though they can also function as source control for infectious illnesses.^{Footnote 235} See: source control

Precautionary principle – A key decision-making principle stating that if activities might harm human health or the environment, precautions should be used even before there’s complete scientific certainty.

RAT – Rapid antigen test, sometimes called a lateral flow test. A quick test that can be used at work or home, which works by detecting the protein from a specific virus.

Respirator, respirator mask – A type of mask or device that's been tested and certified to protect wearers from breathing in airborne hazards. See: mask

Sanitization – The process of reducing the amount of germs on a surface to levels considered safe. See: cleaning, disinfection

Source control – Stopping a hazard at its source, to prevent it from reaching people. Considered the best way to prevent a hazard.^{Footnote 236}

Standard – Also known as a “technical standard.” A set of best-practice rules, guidelines, and definitions created by an authoritative expert body, which different organizations can follow to get consistent outcomes. Following some standards is voluntary, while others are required by law. See: ASHRAE, CSA

Surgical mask – Also referred to as a procedure mask or medical mask. Loose-fitting face coverings that provide a barrier against larger splashes and particles, but are not designed or approved for protection against airborne hazards.^{Footnote 237} See: mask, particle (particulate matter)

UVGI – Ultraviolet germicidal irradiation. A disinfection method that uses UV (ultraviolet) light to help kill germs or make them harmless.

Ventilation – The process of moving air in and out of a space, often to supply clean air and move out contaminated air. See: HVAC

Wastewater surveillance – A method of tracking community disease levels by testing for specific bacteria or viruses in sewer system water. An important early warning system for rising disease levels, or for new variants of illnesses.