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Occupational Health and Safety Act Ontario: A Guide for Employers


Workplace health and safety standards in Ontario are set down in the province’s Occupational Health and Safety Act (OHSA).

What is the Occupational Health and Safety Act?

The Occupational Health and Safety Act Ontario is the key legislation regulating health and safety in Ontario workplaces. It sets down health & safety policies and procedures for employers to follow to prevent and manage safety hazards and risks in the workplace. OHSA Ontario helps employers create healthy and safe workplaces while ensuring employees are also aware of their rights and responsibilities.

The OHSA also outlines the enforcement measures in cases of non-compliance with the Act.

The Ontario Ministry of Labour, Training and Skills Development is responsible for promoting, regulating, and enforcing the Ontario Occupational Health and Safety Act.

Who does the Ontario Occupational Health and Safety Act apply to?

The OHSA Ontario applies to most workers, supervisors, employers, and workplaces in the province. This also includes constructors, suppliers, contractors, and subcontractors.

The OHSA Ontario defines a worker as a “person who performs work or supplies services for monetary compensation”. An employer is described as a person who “employs or contracts for the services of one or more workers”.

Any place in, on or near to where a worker works – be it a building, a construction site, a road, or even a beach – is defined by the OHSA as a workplace.

Who is excluded from the Act?

The Ontario Occupational Health and Safety Act does not apply to federally regulated workplaces, such as banks, post offices, airlines, etc. It also excludes owners and workers in a private residence and farms run by self-employed persons with no staff.

However, the OHSA does apply with some limitations and exceptions, to all farming operations.

Certain OHSA provisions, such as those relating to specific employer duties, hazardous materials, notification, and enforcement, are applicable with necessary modifications to self-employed persons.

It also applies to teachers with some specified limitations and conditions found in O. Reg. 857: Teachers.

What is the purpose of the Ontario Occupational Health and Safety Act?

The Ontario Occupational Health and Safety Act seeks to establish a workplace Internal Responsibility System (IRS). It does so by defining the duties of all workplace parties and the part they play towards ensuring health and safety in the workplace.

OHSA Ontario also sets down comprehensive policies and protocols on factors that affect workplace health and safety such as design, controls, supervision of work, among others.

What are the three rights of workers under OHSA Ontario?

Employees in Ontario have three significant rights under the OHSA:

The right to know

Employees have the right to know about the potential hazards in their line of work. Employers are required to inform and instruct employees about the work hazards, provide them training and information on how to protect their health and safety at work, as well provide supervision.

The right to participate

Workers have the right to have a voice in the management of workplace health and safety issues. This right is exercised either through a worker member on the joint health and safety committees or through a worker health and safety representative.

The right to refuse

All workers covered by OHSA Ontario have the right to refuse work if it puts their or another worker’s health and safety at risk. In some cases, members of a workplace joint health and safety committee, who are certified, have the right to stop work that is dangerous to any employee.

What role do Joint Health and Safety Committees (JHSC) play in workplace health and safety?

Joint Health and Safety Committees are important for enforcing the Internal Responsibility System. A JHSC is composed of representatives of both workers and the management. If you have 20 or more employees in your workplace, you are required to have a JHSC with at least two members. The committee member requirement goes up to four if employ a staff of 50 or more.

The JHSCs have numerous powers that include identifying hazards, carrying out workplace inspections, investigating work refusals, critical injuries, or fatalities, and making recommendations to employers on improving workplace health and safety.

Under OHSA Ontario, employers are required to cooperate with the JHSCs.

Who is a certified member of a JHSC?

A certified JHSC member is someone who has undertaken specialized training in occupational health and safety and has been certified by the Chief Prevention Officer under the OHSA as of April 1, 2012.

Previously, (before April 1, 2012), JHSC members were certified by the Workplace Safety and Insurance Board (WSIB) under the Workplace Safety and Insurance Act, 1997. These certifications are still valid and recognized under the OHSA.

The OHSA grants specific powers to the certified member. Employers and constructors must ensure that their workplace JHSC has at least two certified members (one representing employees and the other the employer/constructor).

What about health and safety representatives?

If you employ fewer than 20 but more than five workers, you are required to have a health and safety representative of the workers in place of a committee. Unless a designated substance (chemical agents and hazardous materials) regulation applies to your workplace, in which case you’ll be required to have a JHSC.

The health and safety representative must be selected by workers who don’t have managerial functions and who will be represented by the representative, or by the union if there is one.

Health and safety representatives exercise many of the same powers as JHSCs, except for the power to stop work. Employers are required to cooperate with the health and safety representative.

Please note that workplace with a staff of one to five are not required to have a JHSC or a health and safety representative unless a designated substance regulation applies to the workplace.

What are the general duties of employers under the Ontario Occupational Health and Safety Act?

The OHSA Ontario sets down the legal duties for employers, constructors, supervisors, owners, suppliers, licensees, officers of a corporation and employees, among others.

The Act defines an employer as one “who employs or contracts for the services of one or more workers”.

Employers have the greatest share of responsibility in ensuring health and safety in the workplace. They have a duty to ensure their workers have access to prescribed equipment, materials, and protective devices that are in good condition. They are also required to make sure that the workplace observes prescribed measures and procedures.

Other employer obligations include (but are not limited to):

  • instructing, informing, and supervising workers to protect their health and safety
  • helping during a medical emergency by sharing relevant information (including confidential business information) with a qualified medical practitioner to aid in diagnosis or treatment
  • appointing competent persons as supervisors
  • helping joint health and safety committees and health and safety representatives in performing their roles
  • taking every precaution reasonable in the circumstances for the protection of a worker
  • posting a copy of the OHSA in the workplace, as well as explanatory material prepared by the Ministry of Labour, Training and Skills Development on the rights, responsibilities, and duties of workers in English and in the language majorly spoken in the workplace
  • preparing and implementing a written occupational health and safety policy if they employ more than five workers, and reviewing that policy at least once a year
  • posting a copy of the occupational health and safety policy in the workplace where it is easily accessible by workers

What does a competent person mean under the OHSA?

The OHSA defines a competent person as one who is:

  • qualified because of knowledge, training, and experience to supervise work
  • familiar with the OHSA and the regulations that apply to the work
  • knowledgeable of any potential or actual danger to health or safety in the workplace

Employers can also appoint themselves as supervisors if they meet all of the above criteria.

Basic occupational health and safety awareness training for workers and supervisors

Employers are also required to ensure that their workers and supervisors complete a mandatory occupational health and safety awareness training. This requirement is applicable to all workplaces covered under the OHSA. The purpose of the training is to teach workers and supervisors about their rights and responsibilities and major workplace health and safety concerns. You can read more about this requirement in our blog Employer FAQs on Ontario Health and Safety Awareness Training.

Employers also have specific duties with regards to workplace violence and harassment and toxic substances in the workplaces.

Workplace violence and harassment

The Occupational Health and Safety Act requires employers to create policies on workplace violence and workplace harassment. They must also review these policies at least once a year.

If an employer has a regular staff of six or more, the policies must be in writing and posted in the workplace where all employees are likely to see them. The employer is also required to develop a program to put these policies in effect.

The workplace violence program must include:

  • measures and procedures to control risks detected during a risk assessment
  • measures and procedures on how incidents of workplace violence are to be reported by workers
  • measures and procedures for seeking immediate assistance when workplace violence occurs or is likely to occur
  • The protocol the employer will follow to investigate and address incidents or complaints of workplace violence

A workplace harassment program must detail:

  • measures and procedures for workers to report incidents of workplace harassment to the employer or supervisor, and to another person if the employer or supervisor is the alleged harasser
  • how incidents or complaints of workplace harassment will be investigated and addressed
  • how information gained about an incident or complaint of workplace harassment, including identifying information about the parties involved, will not be revealed unless essential for the purposes of investigating the incident or complaint, or for taking corrective action, or is otherwise required by law
  • How certain workers will be informed of the results of the inquiry and of any remedial action

The workplace harassment program must be in writing. It must be created and maintained in consultation with the Joint Health and Safety Committee (JHSC) or health and safety representative.

All employees must be aware of the provisions of workplace violence and harassment policies and programs.

Under OHSA Ontario, employers and supervisors are required to provide a worker with information, including personal details, related to a risk of workplace violence from a person with a history of violent behaviour.

Workers in professions with a higher risk of violence may need more frequent or intensive instruction or specialized training.

Toxic substances

What is a designated substance?

A toxic substance that is known to be very hazardous to the health and safety of workers is marked as a designated substance. Under the OHSA, the Lieutenant Governor in Council (LGIC) can prescribe a toxic substance as a “designated substance”. The LGIC can also prohibit, regulate, restrict, limit, or control the use, handling and removal of designated substances in regulated workplaces.

There are regulations on designated substances, on use of asbestos on construction projects, buildings and repair operations, and control of exposure to biological or chemical agents.

What is a Section 33 order of the OHSA?

Section 33 of the OHSA requires a Director of the Ministry of Labour, Training and Skills Development to issue an order to the employer if the director has reason to believe that a toxic substance (Section 33 orders do not apply to designated substances) used or intended to be used in the workplace is likely to jeopardize the health and safety of a worker.

The order states the “use, intended use, presence or manner of use be prohibited, limited or restricted as specified, or subject to conditions regarding administrative control, work practices, engineering controls and time limits for compliance.”

What should employers do when they receive a Section 33 order?

Employers are required to comply with the order. They must also provide a copy of the order to the joint health and safety committee, or health and safety representative and trade union, if any. They should also post the order in the workplace in a place where it is visible and accessible by workers affected by use of the said toxic substance.

Is there scope to appeal a Section 33 order?

Yes. The employer, worker, or trade union may appeal a Section 33 order by giving written notice to the Minister of Labour within 14 days of the order being issued.

What does WHIMS stand for?

WHIMS stands for Workplace Hazardous Materials Information System.

What is the purpose of WHIMS?

Its purpose is to provide employers and workers with health and safety information about hazardous products or chemicals they may be exposed to at work.

When was WHIMS implemented?

WHIMS was implemented across Canada in 1988 and the Ontario OHSA was amended to include Regulation 860: Workplace Hazardous Materials Information System. In 2015, WHIMS was aligned with the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) and came to be known as WHIMS 2015.

Is WHIMS required by law?

All employers required to follow Regulation 860 should be compliant with WHMIS 2015.

WHIMS requires that hazardous product suppliers must label their products and provide safety data sheets before importing or selling their products. Employers must share information about workplace hazardous products with their employees and provide worker education programs.

Who does Ontario’s WHMIS legislation apply to?

Ontario’s WHMIS legislation applies to all workplaces except farms.

Is the WHMIS training mandatory for all Ontario workers?

All Canadians who work with or are potentially exposed to hazardous substances are required to take the WHIMS training.

What are the employer’s duties regarding hazardous materials as per the OHSA?

Besides general employer duties, employers also have specific duties in the OHSA relating to hazardous materials. These include:

  • identifying hazardous materials in the manner prescribed by the law
  • obtaining or making (as may be prescribed) current Safety Data Sheets (SDSs) for all hazardous materials in the workplace
  • ensuring workers exposed or likely to be exposed to hazardous materials participate in the prescribed instruction and training
  • reviewing all biological and chemical agents produced for own use to verify if they are hazardous

Employers must not handle, use, or store hazardous materials in the workplace unless the above-mentioned requirements are met.

What if an employer is unable to get a required label or SDS?

If the employer is not able to procure the required label or SDS after making all reasonable efforts to do so, they must notify a Director of the Ministry of Labour in writing.

What are the requirements for education of workers?

Employers are required to ensure that workers who work with or who may be exposed in the line of their work to a hazardous product are apprised on:

  • the information required on labels, and the purpose and importance of that data
  • the information required on SDSs and its purpose and significance
  • procedures for the safe use, storage, handling, and disposal of a hazardous product
  • procedures to be followed where fugitive emissions are present
  • procedures to be followed in case of an emergency involving a hazardous product

How is WHMIS enforced?

The Ministry of Labour, Training and Skills Development enforces the federal and Ontario WHMIS. Doing so ensures suppliers of hazardous products and employers do not require inspections by both federal and provincial inspectors. The Ministry of Labour inspectors monitor compliance with the federal Hazardous Products Act (HPA), the Hazardous Products Regulations (HPR), as well as the OHSA, and the WHMIS Regulation.

What are the duties of workers under the OHSA?

Under the Occupational Health and Safety Act, employees must:

  • carry out their work in compliance with the OHSA and regulations
  • make use of any equipment, protective devices or clothing required by the employer
  • inform the employer or supervisor about any known missing or defective equipment or protective device that may put their health and safety or that of other worker at risk
  • report any hazard or violation of the Act or regulations to the employer or supervisor
  • Not remove or make ineffective any protective device required by the employer or by the regulations. The only circumstance in which an employee may remove a protective device is where it has been substituted with an acceptable temporary protective device. Once there is no longer a need to remove the required protective device, it must be replaced immediately.
  • not use or operate any equipment or work in a way that may endanger any worker
  • not participate in any prank, contest, feat of strength, unnecessary running, or rough and boisterous behaviour.

How is OHSA Ontario enforced by the Ministry of Labour?

The MOL ensures compliance with the Occupational Health and Safety Act and regulations through workplace inspections. MOL inspectors are usually appointed as Provincial Offences Officers under the Provincial Offences Act to do so. MOL inspectors can:

  • carry out proactive and reactive inspections of provincially regulated workplaces
  • issue requirements or administrative orders where the OHSA or its regulations are being flouted
  • investigate critical injuries, fatalities, work refusals and health and safety complaints, and,
  • initiate prosecution for offences under the OHSA and/or its regulations.

Inspectors may also provide workplaces with compliance information and refer them to relevant health and safety associations. If an inspector has reasonable grounds to believe that a workplace party has committed an offence, they can initiate a prosecution.

What are some other things workplace parties must keep in mind about inspections?

All workplace parties must cooperate with the MOL inspector during an inspection. It’s an offence under the OHSA to interfere with an inspector while they are carrying out their duties under the Act. This includes providing the inspector with false information or withholding information or obstructing any monitoring information left on the premises.

Everyone is required to assist an inspector in the exercise of their powers under the OHSA.

What are the rules around an employer’s notice of compliance with an order?

If an employer has received an order to correct a contravention of OHSA Ontario, the employer must send written notification to the Ministry of Labour within three days of complying with the order.

This notice of compliance must be signed by the employer and should be accompanied by a signed statement from a worker member of the joint health and safety committee or a health and safety representative. The statement should make it clear whether the worker member agrees or disagrees with the employer’s notice of compliance. If they disagree, the notice should have a statement stating the member or representative has declined to sign the statement.

The employer must also post copies of the notice of compliance and the original order in the workplace where it is visible and accessible by workers. The notice must be posted for 14 days after it has been submitted to the Ministry of Labour.

Please note that submitting a notice of compliance does not mean that compliance has been achieved. That can only be decided by an MOL inspector.

Can an inspector’s orders be appealed?

Yes. Any employer, owner, worker, constructor, or union can appeal to the Ontario Labour Relations Board within 30 days of the order being issued. You may also request the Ontario Labour Relations Board to halt the order until the appeal has been settled. If an inspector decides not to issue an order, that can also be appealed.

The Board decision on the matter is final.

What are the offences and penalties for non-compliance?

Workers, employers, or supervisors can be prosecuted for breaching the OHSA or for non-compliance with an order of an inspector, director, or minister. If found guilty and convicted, a workplace party may receive a fine and or a jail term.

The Working for Workers Act, 2022 amended the OHSA to increase fines for certain convictions. It also increased the limitation period for instituting a prosecution from one year to two years.

The maximum fine for a corporation is $1,500,000 under the OHSA. While this remains unchanged, the Act has amended the OHSA to state that a director or officer of a corporation who fails to ensure the corporation complies with the OHSA, is guilty of an offence and on conviction is liable to a fine up to $1,500,000, an imprisonment for a term of not more than 12 months, or to both.

The Act also lists certain aggravating factors to be considered when determining a penalty. Some of these factors include, but are not limited to, if the offence resulted in the death, serious injury or illness of one or more employees, if the offence was committed recklessly, if the defendant lacks remorse, and so on.

The fines for an OHSA contravention by an individual (who is not a director or officer) have been increased from $100,000 to up to $500,000, depending on the contravention and any aggravating circumstances as listed above.

The new limitation period and increased fines/penalties provisions come into effect on July 1, 2022.

What other amendments have been made to the Ontario OHSA by the Working for Workers Act, 2022?

Another major amendment to the OHSA is that certain employers will now have to provide naloxone kits in the workplace. On December 9, 2022, amendments to Bill 88: Working for Workers Act, 2022, now require certain employers to have a naloxone kit in the workplace, effective June 1, 2023.

The Working for Workers Act, 2022 states that, starting on June 1, 2023, where an employer becomes aware, or ought reasonably to be aware, that there may be a risk of an employee having an opioid overdose in the workplace, the employer must provide and maintain in good condition a naloxone kit to reverse the potentially fatal effects of an opioid overdose.

The Act also states that the employer must ensure that, at any time there are workers in the workplace, the naloxone kit is in the charge of a worker who works in the vicinity of the kit and who has received appropriate training. Appropriate training includes having the ability to recognize an opioid overdose, to administer naloxone, and to acquaint the worker with any hazards related to same.

Work refusals

Do workers have the right to refuse work under OHSA Ontario?

Under OHSA Ontario, all workers have the right to refuse work they have valid reason to believe endangers their health and safety or that of another worker. An employee can also refuse work when faced with or with the likelihood of workplace violence.

Can all workers exercise the right to refuse unsafe work?

The right to turn down unsafe work is limited for police officers, firefighters, those working in correctional institutions and similar facilities. It is also restricted for “health care workers and persons employed in workplaces like hospitals, nursing homes, sanatoriums, homes for the aged, psychiatric institutions, mental health centres or rehabilitation facilities, residential group homes for persons with behavioural or emotional problems or a physical, mental or developmental disability, ambulance services, first aid clinics, licensed laboratories—or in any laundry, food service, power plant or technical service used by one of the above.”

What is the procedure to follow in case of a work refusal?

There is a specific procedure laid down that must be followed in any work refusal.

Stage 1

When a worker has valid reason to believe that their work is unsafe, they must report the refusal to the supervisor or employer. If the worker wishes, they could also advise the worker safety representative and/or management representative. After reporting the refusal, the worker sits in a safe area.

The employer or supervisor is then required to investigate the matter in the presence of the worker and the worker safety representative.

If the matter is resolved, the worker can go back to work. But if it isn’t, the work refusal proceeds to the next stage.

Stage 2

The worker or employer or their representative then informs the Ministry of Labour, Training and Skills Development.

The MOL inspector investigates the matter in the presence of the worker, safety representative and supervisor or management representative.

The inspector provides their decision in writing to the worker, management representative/supervisor and safety representative. Once the changes ordered are implemented by the employer, the worker goes back to work.

While the MOL investigation is ongoing, the worker who refuses unsafe work may be offered other work if it doesn’t clash with a collective agreement.

Can the refused work be offered to another worker?

Yes. The refused work can be offered to another worker. But the employer must inform the new worker that the work being offered to them has been refused and is being investigated for being unsafe. The employer must do so in the presence of:

  • a member of the joint health and safety committee who represents workers; or
  • a health and safety representative, or
  • a worker who due to skill, experience and training is selected by the trade union that represents the worker or, in the absence of a trade union, by the workers to represent them.

On what grounds can a worker refuse work?

Workers can refuse work if they have a valid reason to believe that:

  • any machine, equipment, or tool they are using or are told to use is likely to endanger them or another worker
  • the physical condition of the workplace or workstation is likely to put their safety at risk
  • workplace violence is likely to endanger them
  • any machine, equipment, or tool that the worker is using, or the physical condition of the workplace, breaches the provisions of OHSA Ontario or regulations and is likely to put worker health and safety at risk

Does the employer have to pay the refusing worker while the MOL investigation is on?

According to the Ministry of Labour the refusing worker is at work during the first stage of a work refusal and, therefore, entitled to be paid.

Can an employer discipline a worker who refuses work?

No. The employer is barred from penalizing, dismissing, disciplining, suspending, or threatening a worker who has followed or sought implementation of the OHSA in the workplace.

Who has the right to stop work?

The Occupational Health and Safety Act allows specified individuals to stop work in “dangerous circumstances”.

In most cases, a directive from both the worker and management certified joint health and safety committee members is needed to stop dangerous work. In some special circumstances, a single certified member may have this right.

What qualify as “dangerous circumstances”?

This would mean conditions in which:

  • the OHSA or the regulations are being violated, and
  • the violation poses a danger or a hazard to a worker, and
  • any delay in controlling the danger or hazard may seriously endanger a worker

Unilateral work stoppage

If a workplace certified member or an MOL inspector has good cause to believe that the procedure for joint stoppage of work will not be enough to protect the workers from serious risk to their health or safety, they may apply to the Ontario Labour Relations Board for a specified declaration or recommendation against the employer.

The decision of the Ontario Labour Relations Board on any such application is final.

Do you need help ensuring your workplace is compliant with the Ontario Occupational Health and Safety Act?

By fulfilling your health and safety obligations as an employer, you not only ensure the safety of your employees, but also protect your business from costly fines.

Our experts can help you prepare for workplace inspections, develop relevant health and safety policies, and assist you with any health and safety advice you need. To learn more about how our services can benefit your business, call us today at 1 (833) 247-3652.

This article provides a brief overview of the Ontario Occupational Health and Safety Act. It is not a legal document. For more details, please refer to the OHSA Ontario.

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