Construction Safety Glossary: 39 Terms (Canada)

ACSA (Alberta Construction Safety Association): The certifying partner for COR in Alberta construction. To qualify, an employer's external audit must score at least 80 percent overall and 50 percent on each element, and the COR is typically valid for three years with annual maintenance audits. Source: Alberta Construction Safety Association: COR Process.
Click Before You Dig: A national portal that links to the locate request service for each province and territory. Contractors and homeowners use it to request locates of buried utility lines before digging. Source: Click Before You Dig.
CNESST: The Commission des normes, de l'équité, de la santé et de la sécurité du travail, Quebec's workplace health and safety body. Its inspectors work on construction sites and other workplaces, support prevention, handle complaints and work refusals, and investigate workplace accidents. Source: Quebec.ca: Occupational health and safety inspector.
Competent person (Ontario): Under Ontario OHSA s.1, a person who is qualified because of knowledge, training and experience to organize the work and its performance, is familiar with the Act and regulations that apply to the work, and knows about any potential or actual danger to health or safety in the workplace. Supervisors in Ontario must be competent persons. Source: Ontario Occupational Health and Safety Act, R.S.O. 1990, c. O.1.
Competent worker (Ontario): Under O. Reg. 213/91, a worker who, for specific work, is qualified because of knowledge, training and experience to perform it, is familiar with the OHSA and the regulations that apply to it, and knows about all potential or actual danger to health or safety in the work. Source: Ontario O. Reg. 213/91: Construction Projects.
Confined space: Under Ontario O. Reg. 632/05, a fully or partially enclosed space that is not both designed and built for continuous human occupancy, and where atmospheric hazards may occur because of its construction, location or contents or the work done in it. Ontario requires a written hazard assessment, plan and rescue procedures before entry. Source: Ontario O. Reg. 632/05: Confined Spaces.
Constructor: Ontario's term for the person who undertakes a construction project for an owner, including an owner who does the project themselves or through more than one employer. The constructor must ensure the OHSA and regulations are followed on the project and that workers are protected (OHSA s.23). Source: Ontario Occupational Health and Safety Act, R.S.O. 1990, c. O.1.
COR (Certificate of Recognition): A voluntary, nationally trademarked certification for employers whose health and safety management system passes an audit. It is endorsed by the Canadian Federation of Construction Safety Associations and is a prequalification requirement for many contractors. It is granted by a certifying partner in each province, such as IHSA in Ontario. Source: IHSA: Certificate of Recognition (COR) in Ontario.
Emergency response plan: A plan for emergencies that may need rescue or evacuation. In Alberta every employer must have one, made with affected workers and kept current. It must cover potential emergencies, procedures, emergency equipment, alarms and communication, first aid, rescue and evacuation procedures, and the designated rescue and evacuation workers. Source: Alberta OHS Code, Part 7: Emergency Preparedness and Response.
Energy Safety Canada: The national safety association for Canada's energy industry. It provides safety training and is a COR certifying partner for energy sector employers, with one audit process recognized across BC, Alberta and Saskatchewan. Source: Energy Safety Canada: COR and SECOR Overview.
Fall protection plan: A written plan for work where workers could fall. Alberta requires one when a worker may fall 3 metres or more without guardrails, and BC when a fall of 7.5 metres or more may occur without permanent guardrails. Alberta's plan must cover the fall hazards, system, anchors, clearance, how the system is set up and used, and rescue procedures. Source: Alberta OHS Code, Part 9: Fall Protection.
FLHA (field level hazard assessment): A written hazard assessment done at the work site, with the crew, just before a task starts and again when conditions change. No province uses the name "FLHA" in law, but it is the usual way to meet hazard assessment rules such as Alberta OHS Code s.7 to s.9: assess before work begins, write it down, date it, and involve affected workers. Source: Alberta OHS Code, Part 2: Hazard Assessment, Elimination and Control.
Ground disturbance: Any work on or under the existing surface that disturbs or displaces the soil, with limited exceptions such as routine minor road maintenance. In Alberta, before the ground is disturbed the employer must have buried facilities located and marked by their owners. Source: Alberta OHS Code, Part 32: Excavating and Tunnelling.
H2S (hydrogen sulfide): A colourless gas with a rotten egg odour that is very toxic and can be fatal if inhaled. It is also extremely flammable and can build up to dangerous levels in low-lying areas, especially inside confined spaces. Source: CCOHS Chemical Profiles: Hydrogen Sulfide.
Hazard: Any source of potential damage or harm to someone or something. CSA Z1002 defines a hazard as a potential source of harm to a worker, where harm means physical injury or damage to health. Source: CCOHS OSH Answers: Hazard Identification.
Hazard assessment: The process of identifying existing and potential hazards at a work site and choosing how to eliminate or control them. In Alberta the employer must do it before work begins, prepare a written report with the control methods, record the date, and repeat it when work processes or the site change. Source: Alberta OHS Code, Part 2: Hazard Assessment, Elimination and Control.
Health and safety representative: A worker, not part of management, who represents workers on health and safety at smaller workplaces. In Alberta an employer that regularly employs 5 to 19 workers must designate one. In Ontario one is required where there is no committee and the workplace regularly has more than five workers. Source: Alberta OHS Act, Part 2: Health and Safety Committees, Representatives and Programs.
Hierarchy of controls: A ranking of hazard controls from most to least effective: elimination, substitution, engineering controls, administrative controls, then personal protective equipment. You start at the top and only move down when the higher level is not possible. Alberta OHS Code s.9 sets the same order in law. Source: CCOHS OSH Answers: Hierarchy of Controls.
IHSA (Infrastructure Health and Safety Association): Ontario's safe workplace association for construction, electrical utilities, transportation and related industries, designated under the Occupational Health and Safety Act. It provides training, resources and consulting, and is the body that grants COR in Ontario. Source: IHSA: About Us.
Internal responsibility system: The idea behind health and safety law in every Canadian jurisdiction: everyone in the workplace, employers and workers alike, is responsible for their own safety and the safety of co-workers. Employers keep policies and procedures for a safe workplace, and workers follow safe work practices and report hazards. Source: CCOHS OSH Answers: Internal Responsibility System.
JHA (job hazard analysis) / JSA: A method of breaking a job into its basic steps, identifying the potential hazards of each step, and setting the safest way to do it. It is also called a job safety analysis or job hazard breakdown. The basic steps are: select the job, break it into steps, identify hazards, determine controls, and communicate the results. Source: CCOHS OSH Answers: Job Safety Analysis.
Joint health and safety committee (JHSC): A committee of worker and management representatives that works on health and safety issues at a workplace. In Ontario one is required where 20 or more workers are regularly employed, though not for a constructor at a project expected to last less than three months. Other provinces have similar rules under slightly different names. Source: Ontario Occupational Health and Safety Act, R.S.O. 1990, c. O.1.
Locate: The marking of where buried utilities such as gas lines, cables and pipes are, done by the owner or a locator before digging. In Ontario a locate is valid for 60 days unless another period is prescribed or the locator gives a longer one. Source: Ontario Underground Infrastructure Notification System Act, 2012.
Lockout: Placing a lock and tag on an energy-isolating device under an established procedure, to show it must not be operated until the lock or tag is removed. Lockout is one method within the broader practice of hazardous energy control. Source: CCOHS OSH Answers: Hazardous Energy Control Programs.
Multiple-employer workplace: A BC term for a workplace where workers of 2 or more employers are working at the same time. The prime contractor of a multiple-employer workplace must coordinate the health and safety activities of everyone there. Source: WorkSafeBC: Workers Compensation Act, Part 2 (Occupational Health and Safety).
Muster point: The place where workers gather after an evacuation so everyone can be accounted for. It is part of the evacuation procedures in a site's emergency response plan, which Alberta requires every employer to have. Source: Alberta OHS Code, Part 7: Emergency Preparedness and Response.
Near miss: An event that could have caused injury or damage but did not. It should be investigated the same way as an incident so the next one is prevented. Source: CCOHS OSH Answers: Incident Investigation.
PPE (personal protective equipment): Equipment worn or used by a worker to reduce exposure to specific hazards, such as respirators, gloves, fall protection, and head, eye and foot protection. PPE does not reduce the hazard itself, so it is the last control in the hierarchy of controls. Source: CCOHS OSH Answers: Designing an Effective PPE Program.
Prime contractor: The person or company responsible for coordinating health and safety on a work site with 2 or more employers. In Alberta every construction and oil and gas work site with 2 or more employers must have one, designated in writing, and its name must be posted at the site. BC uses the same term for multiple-employer workplaces. Source: Alberta OHS Act, Part 1: General Obligations.
Rescue plan (fall rescue procedure): Written procedures for rescuing a worker whose fall has been stopped by a fall arrest system or safety net. In Ontario the employer must develop them before anyone uses fall arrest or a safety net (O. Reg. 213/91 s.26.1(4)), and Alberta requires them as part of the fall protection plan. Source: Ontario O. Reg. 213/91: Construction Projects.
Right to refuse: A worker's legal right to refuse work they believe on reasonable grounds is dangerous. In Alberta a worker may refuse work that poses an undue hazard, meaning a serious and immediate threat to health and safety, and must promptly report the refusal and the reasons to the employer or supervisor. Source: Alberta OHS Act, Part 3: Dangerous Work and Disciplinary Action.
Risk assessment: The full process of identifying hazards, analysing and evaluating the risk from each one, and deciding how to eliminate the hazard or control the risk. Hazard identification is the first step of a risk assessment. Source: CCOHS OSH Answers: Hazard and Risk, General.
SDS (safety data sheet): A summary document that gives the hazards of a hazardous product and advice on safety precautions. It is usually written by the manufacturer or supplier and must be provided when the product is sold. It has more detail than the product label. Source: CCOHS OSH Answers: WHMIS, Safety Data Sheet.
SECOR: The Small Employer Certificate of Recognition, a simplified version of COR for companies with 10 or fewer employees. It lets smaller employers meet COR requirements without a full-scale audit. Source: Energy Safety Canada: COR and SECOR Overview.
Stop work (bilateral work stoppage): In Ontario, if two certified joint committee members, one from each side, find that dangerous circumstances exist, they may direct the constructor or employer to stop the work. This is OHSA s.45. Source: Ontario Occupational Health and Safety Act, R.S.O. 1990, c. O.1.
Supervisor: Under Ontario OHSA s.1, a person who has charge of a workplace or authority over a worker. Supervisors have their own legal duties, such as advising workers of any potential or actual danger to their health or safety that the supervisor is aware of. Source: Ontario Occupational Health and Safety Act, R.S.O. 1990, c. O.1.
WHMIS: The Workplace Hazardous Materials Information System, Canada's system for giving hazard information on hazardous products used at work. Its main parts are hazard classification, labels, safety data sheets, and worker education and training. It is aligned with the Globally Harmonized System (GHS), and the latest supplier transition period ended on December 15, 2025. Source: CCOHS OSH Answers: WHMIS, General.
Working alone: Working where help would not be readily available if there is an emergency or the worker is injured or ill. Alberta treats it as a hazard that must be assessed, and requires an effective communication system with regular contact. BC requires a written check-in procedure, including a check at the end of the shift. Source: Alberta OHS Code, Part 28: Working Alone.
Working at Heights training: Ontario's mandatory fall protection training for construction workers who may use travel restraint, fall restricting, fall arrest, safety nets, work belts or safety belts. The program and provider must be approved by the Chief Prevention Officer, and the training is valid for three years. Source: Ontario O. Reg. 297/13: Occupational Health and Safety Awareness and Training.

Construction safety terms explained