Disability and Causation in Workers' Compensation (7:IX)

This information applies to British Columbia, Canada. Last reviewed for legal accuracy by the Law Students' Legal Advice Program on July 21, 2022.

A. Types of Claims

Before a compensation claim can be accepted, the Board must find that the worker’s injury, death, or disease was disabling and that the disability occurred as a result of employment. The WCA addresses these matters differently for different types of injuries and conditions.

• Sections 134 and 146 [Former Act, s. 5]: personal injury (physical or physical/psychological)
• Section 135 [Former Act, s. 5.1]: psychological injury only (“mental stress”)
• Section 136(1)[Former Act, s. 6(1)]): occupational disease (Occupational Disease) – no presumption of work causation
• Section 137 [Former Act, s. 6(3)]: Occupational Disease – presumption of work causation
• Section 145[Former Act, s. 7]: hearing loss

Detailed policies regarding each of these conditions are set out in the RSCM II. Chapter 3 sets out policies for personal and psychological injuries and compensable consequences. Chapter 4 sets out policies for all Occupational Disease, including repetitive strain injuries and hearing loss. Students handling appeals should note that most causation disputes come down to matters of evidence, and the policies provide important guidance on what evidence is required in each case.

B. Injury or Disease or Both?

Because the statutory and policy requirements for an injury and Occupational Disease are different, it is important to consider the worker’s disability under the correct relevant category. Sometimes this is not clear.

Policy #C3-12.00 of the RSCM II has a helpful section on the distinction between an “injury” and a “disease”. Some conditions, like tendonitis or hearing loss, can be either an injury or a disease, depending on the circumstances of the injury. For example, hearing loss from a single occurrence like an explosion is treated as an injury while gradual loss of hearing due to occupational noise is treated as a disease.

Sometimes, a worker is disabled by a combination of a slow-developing disease followed by a single event. The combination results in a significant disability, although neither event by itself would have been disabling. This is a difficult causation case. While the single event may not be sufficient to injure a healthy person, the worker is “working hurt” so a minor event is sufficient to disable him. This is the compensation version of the “thin skull” victim in tort law. The Board may not accept work causation in the initial decision and deny the claim as not meeting the causal standard under WCA ss. 134 and 146 [Former Act, s. 5]. On review or appeal, the best way to address this matter is to have good evidence, preferably medical evidence, of the worker’s medical condition prior to the single event. The key for a finding of work causation under s. 134 is “causative significance”. Further, it is noted in court decisions that compensability will be denied only if personal or non-employment related factors are so dominant or exclusive that the compensable injury is not a significant causal factor (WCAT-2009-02226, affirmed by WCAT-2011-92511).

In some cases, the worker’s pre-existing condition is actually a developing Occupational Disease, such as gradual onset repetitive strain or gradual hearing loss. In these cases, you may wish to ask the Board to accept the pre-existing condition as a compensable Occupational Disease under section 136 and 137 [Former Act, s. 6]. If the Board denies this aspect as well, you may appeal this denial and join the two appeals together at the Review Division or WCAT so an appeal panel may consider the “whole worker”.

C. Compensable Aggravation

For both injuries and Occupational Diseases, it is also recognized that the worker can have a pre-existing condition which is aggravated or activated by the compensable injury or disease. For injuries, the relevant policy is set out in RSCM II #16.00; for Occupational Diseases, the policy is set out in RSCM II #25.20. It is necessary to distinguish between injuries or death resulting from employment (which are compensable), and injuries resulting from pre-existing conditions or diseases (which are not compensable). There must have been something in the employment activity or situation that had causative significance in producing the injury or death. In adjudicating these types of claims, the Board considers:

• The nature and extent of pre-existing injury;
• The nature and extent of the employment activity; and
• The degree to which the employment activity may have affected the pre-existing injury.

If the pre-existing condition meets the test for compensable aggravation, this requires an “aggravation” decision separate from a simple acceptance “decision”. For example, the Board may deny that a slip and fall was sufficient to cause a meniscus knee tear in a healthy worker; however, if the worker had pre-existing knee problems, the same claim could have a separate decision accepting an “aggravation” type injury.

If the worker has a pre-existing but non-disabling condition, and the claim is accepted, the worker’s injury is dealt with like any other claim and the whole disability is compensable.

However, if the worker has a pre-existing disabling condition and becomes further disabled in the same body part through a work injury, the Board will apply section 146 of the WCA [Former Act, s.5(5)] or “proportionate entitlement” whereby compensation is paid only for the increase in disability, rather than the whole disability.

D. Section 134: Personal Injury

Chapter 3 – Compensation for Personal Injury is the key chapter of the RSCM II that applies to s. 134 of the WCA [Former Act, s. 5]. This chapter covers the definition of a “personal injury” as well as “arising out of and in the course of employment” and goes on to cover specific circumstances that can prevent an injury from being accepted and specific losses and consequences that can be included in a claim.

1. Did the Injury Happen at Work?

Under sections 134 and 146 of the WCA [Former Act, s. 5], personal injury or death must arise out of, and in the course of, employment in order to be compensable. It is important to check policies and WCAT decisions for qualifying factors, as they can change.

“Arising out of employment” relates to causation and means that the work must have causative significance to the injury. According to well-established jurisprudence, this means that the work does not have to be the sole or even the dominant cause of the injury; it must be only of causative significance greater than being trivial or de minimis: Chima v Workers’ Compensation Appeal Tribunal, 2009 BCSC 1574, Schulmeister v British Columbia (Workers’ Compensation Appeal Tribunal), 2007 BCSC 1580, and v British Columbia (Workers’ Compensation Appeal Tribunal), 2006 BCSC 838. Not all injuries at work are caused by work, as some are naturally occurring conditions which would have happened in any event. For example, a worker with heart disease, who is working in a sedentary job, may have a heart attack at the office. There is likely nothing in the work activity which would have causative significance to this injury.

“In the course of employment” relates to the employment relationship at the time of injury. It generally refers to whether the injury or death happened at the time and place and during an activity reasonably related to the duties and expectations of the employment. Time and place are not strictly limited to the normal hours or work or on the employer’s premises.

Injuries may be caused by the normal actions or movements involved in the workplace as opposed to an abnormal event. For example, injuries caused by overexertion or repetitive movements can still be grounds for compensation even when done during routine work (RCMS II #C3-12.00).

NOTE: There is a statutory presumption that if an injury is caused by an accident at work, the injury is presumed to have occurred in the course of employment (WCA s.134(3) [Former Act, s. 5(4)]). An accident can include someone else’s intentional act.

The determination of whether an injury arose out of and in the course of employment is set out in RCMS II #C3-14.00 and can be made with reference to factors such as:

• whether the injury occurred on the premises of the employer;
• whether it occurred in the process of doing something for the benefit of the employer;
• whether it occurred in the course of action taken in response to instructions from the employer;
• whether it occurred in the course of using equipment or materials supplied by the employer;
• whether the risk to which the worker was exposed was the same as the risk to which they are exposed in the normal course of production;
• whether the injury occurred during a time period for which the worker was being paid;
• whether the injury was caused by some activity of the employer or of a fellow worker;
• whether the injury occurred while the worker was performing activities that were part of their regular job duties; and
• whether the injury occurred while the worker was being supervised by the employer.

This list is not exhaustive, and alone, none of the above factors are conclusive.

RSCM II, Chapter 3 sets out further and detailed criteria for acceptance of a claim under sections 134 and 146 of the WCA [Former Act, s. 5]. Current policy states that the injury need not occur while the worker is engaged in specific productive acts, so long as it occurs within the broad circumstances of carrying out the employment duties. An injury incurred while commuting is generally not a compensable injury; however, travelling may be considered an activity in the course of employment if travel is part of the worker’s duties or if the accident occurs on the employer’s property or on a “captive road” provided and controlled by the employer, such as logging roads used by forestry workers.

If serious and willful misconduct on the part of the worker is the sole cause of the injury, no compensation is paid unless death or severe disability results.

2. Secondary Conditions

Where the worker suffers consequences from the injury, in addition to the injury, these may be “compensable consequences”. Some common compensable consequences of injury include chronic pain and the development of psychological conditions after the initial injury (unless they arise due to the WCB process). The test for whether a secondary condition is compensable is also causative significance, meaning that the initial injury does not have to be the sole or dominant cause of the secondary injury. It must only be of causative significance greater than being trivial.

As discussed above, if the worker suffered from a pre-existing condition and the injury aggravates, accelerates or activates this condition, the resulting aggravation may also be compensable. (Note: this policy is complex and should be consulted for specific details).

The Kovach v Singh (Kovach v WCB), [2000 SCJ No 3] decision upheld the Board’s policy that a worker who is undergoing treatment for a work injury remains in the course of employment, even if the treatment takes place long after the job itself has ended (even years after). This decision means that workers undergoing treatment for an injury or disease generally cannot sue negligent medical providers for medical malpractice.

See also RSCM II #C3-22.00 – 22.40.

E. Section 136: Occupational Diseases

1. Overview of Compensable Occupational Diseases

An Occupational Disease is a particular disease or medical condition which is recognized by the Board as likely or possibly caused by work, based on scientific evidence. The Board “recognizes” an Occupational Disease formally by listing it in a policy. These lists are updated as new scientific evidence becomes available. A “disease” is a broad category which includes exposures, cancer, poisons, repetitive strain injuries, hearing loss and contagious and respiratory diseases.

To determine if a worker’s medical condition is a recognized Occupational Disease, consult the two policy provisions listing the recognized Occupational Diseases: Appendix 2 (RSCM II)/Schedule 1 (WCA), which sets out Occupational Diseases recognized as qualifying for a presumption of work causation for certain industries, and RSCM II #C4-25.00, which sets out additional Occupational Diseases recognized by Regulation. Each type has different tests for work causation, which must be met if the Occupational Disease is to be accepted by the Board as compensable.

2. Occupational Diseases listed in Schedule 1 (Appendix 2 of the RSCM II)

Occupational Diseases listed in WCA Schedule 1 [Former Act, Schedule B] are matched with the particular industries in which they commonly occur. If the worker has that disease and works in the listed industry at the time of disablement, the Occupational Disease is presumed to have been caused by that work unless the contrary is proven (WCA, s. 137 [Former Act, s. 6(3)]). A presumption of work causation only arises for diseases mentioned in Schedule 1 when the worker is working in the listed industry immediately before the date of disablement. Otherwise, no presumption applies. Also, the contrary may be proven in an individual case. For example, where a worker was employed as a coal miner at or before the date of disablement, silicosis is compensable unless it is proven to have been caused by non-work factors such as smoking.

Occupational Diseases in Schedule 1 include certain kinds of cancers, respiratory diseases including asbestosis, and repetitive strain injuries. If a worker has a Schedule 1 disease but does not work in the listed industry, the worker’s Occupational Disease can still be compensable if work causation can be proven under WCA s.136(1) [Former Act, s. 6(1)]. In addition, section 139 of the WCA [Former Act, s. 6.1] sets out a special work presumption for firefighters who suffer a heart attack on the job.

Policy #25.20 of the RSCM II provides a helpful guide to the special rules for a Schedule 1 presumption.

3. Occupational Diseases listed in policy #25.10 RSCM II

Additional Occupational Diseases are listed in RSCM II, #25.10, including many repetitive strain injuries and specific conditions such as plantar fasciitis and Lyme Disease. These diseases must be adjudicated under s. 136(1) of the WCA [Former Act, s.6(1)], where work causation must be proven in each case.

Section 136(1) states that if:

• a worker suffers from an occupational disease and is thereby disabled from earning full wages at the work at which they were employed; or
• the death of a worker is caused by an industrial disease; and
• the disease is due to the nature of any employment in which the worker was employed, whether under one or more employments; then:

compensation is payable as if the disease were a personal injury arising out of and in the course of that employment. The absence of a specific incident may mean that the worker has a disease rather than a personal injury.

In addition to these statutory provisions, RSCM II #C4-25.20 sets out guidance for establishing work causation for Occupational Diseases in general and sets out the Onus of Proof for non-presumptive Occupational Disease causation. This policy can be helpful guidance when framing a submission on causation for a s. 136(1) [Former Act, s. 6(1)] Occupational Disease case.

There are also particular policies applying to particular conditions, organized by type of condition, which are usually referenced in decision letters involving those conditions.

Policies numbered C4-27.00 – 27.40 of the RSCM II apply to particular repetitive strain injuries/activity-related soft tissue disorders (“ASTDs”). NOTE: most ASTDs can be injuries or diseases, and many are listed in Schedule 1 [Former Act, Schedule B] (i.e. may or may not qualify for the work related presumption).

• RSCM II #C4-28.00 for Contagious Diseases (e.g. scabies)
• RSCM II #C4-29.00 – 29.10 for Respiratory Diseases (e.g. asthma, silicosis, asbestosis)
• RSCM II #C4-30.00 for Cancers
• RSCM II #C4-31.00 for Hearing Loss
• RSCM II #C4-32.00 for Other Matters

F. Workers Compensation in Relation to COVID-19:

Along with other benefits such as CERB, CRB, CRSB, CRCB, and the B.C. Emergency Benefit for Workers, it possible to receive compensation from the Board for contracting COVID-19 in the course of employment. The facts required for a successful claim are:

1. There is evidence that the worker has contracted COVID-19; and
2. The nature of the worker’s employment created a risk of contracting the disease significantly greater than the ordinary exposure risk of the public at large. 

It is important to note that a positive COVID-19 test is not required, as a medical diagnosis or other supporting evidence can be sufficient. That being said, some evidence of physical symptoms will be necessary without a conclusive positive test, as WorkSafeBC does not compensate workers for quarantine due to close contact.

In reference to the second factor, the risk related to employment is determined by a whether a worker will be naturally exposed to those who have been diagnosed with COVID-19, such as hospital workers, or workers who have regular close interactions with customers, such as retail workers.

More information can be found at www.worksafebc.com/covid-19.

G. Special Issues for all Occupational Disease cases:

1. Date of Disablement

For an Occupational Disease, the first date of disablement is treated as the “date of injury” for the purpose of calculating the one-year time period to submit a compensation application (WCA, s. 151 [Former Act, s. 55]). Special rules apply for Occupational Disease late applications and for Federal Workers (see RSCM II #25.20).

2. Timely Application & Health Care

For diseases with a long latency period such as asbestosis and most cancers, a timely application may result in only receiving health care benefits at first. These healthcare benefits can include, for example, medical benefits, necessary adjustments to the residential home, and home-care. These benefits may also be claimed by dependants if the worker has died.

3. Standard of Proof

Schedule 1 diseases and the diseases recognized by regulation (RSCM II #25.10) have an “as likely as not” standard of proof for causation (WCA s. 339 [Former Act, s. 99). This means that where the evidence is equally weighted for different interpretations, the interpretation that favours the worker should be preferred. For example, the Supreme Court of Canada upheld a WCAT decision that an unusually high rate of cancer in a group of lab technicians was an Occupational Disease and therefore compensable (Fraser Health Authority v Workers Compensation Appeal Tribunal, 2016 SCC 25). Though experts had found little positive evidence supporting this link, the cancer rate in this group was highly unusual. Combined with the significant possibility of non-trivial exposure to harmful substances in the workplace, WCAT decided that was enough to satisfy the “as likely as not” standard.

4. Survivor Benefits

If a worker’s disease causes death, the worker’s spouse may be entitled to survivor benefits, even if the worker was not eligible for compensation.

NOTE: WorkSafeBC has developed the Exposure Registry Program, which is designed to be a forum for workers, employers or others to report work-related exposures. This registry is intended to track incidents of exposure to substances which are known to be harmful (such as asbestos), as well as exposures which may in the future be shown to cause disease (such as power line emissions). The information obtained through the registry will create a permanent record of a worker’s exposure and will assist WorkSafeBC in establishing that the manifestation of a disease was due to the nature of the employment in which the worker was employed (a requirement under s 136(1)(b), previously 6(1)(b), of the WCA [Former Act, s. 6(1)(b)]). This will simplify the adjudication of future claims for occupational diseases caused by workplace exposure.

H. Section 135 Injury: Psychological Injuries

A worker can claim for diagnosed psychological conditions which arise as a consequence of physical injuries or Occupational Diseases which are accepted under ss. 134, 135, or 146 of the WCA [Former Act, ss. 5 – 6]. Common psychological consequences include chronic pain and depressive disorders. In practice, psychological limitations and restrictions can often be an overlooked aspect of an injured worker’s reduced employability. However, they are important to recognize, diagnose and treat as this may be the difference between a successful rehabilitation and a failed one. When seeking acceptance of a psychological consequence of a compensable physical condition, the causal threshold is the same standard of “causative significance”: Is the accepted physical injury a significant contributing cause of the psychological condition, meaning something more than a trivial or insignificant factor? If so, the psychological consequence is compensable as well, including treatment. The physical injury does not need to be the sole or even most significant cause. See RSCM II #22.30.

However, a worker may suffer a psychological injury alone, with no accompanying physical condition. Common examples include Post Traumatic Stress Disorder (PTSD) or Major Depressive Disorder (MDD). In such cases, the worker can claim for purely psychological injuries from their work under section 135 of the WCA [Former Act, s. 5.1] and RSCM II #C3-24.00 – 24.10.

Section 135 of the WCA [Former Act, s. 5.1] provides for two types of psychological injuries, each with a different causation test. A worker can claim for a psychological injury that is either:

1. A reaction to one or more traumatic events arising out of and in the course of employment; or
2. Predominantly caused by a significant work-related stressor, including bullying or harassment, or a cumulative series of such stressors, arising out of and in the course of employment.

A psychological injury which arises from a traumatic event must meet the usual causation test that employment was “as likely as not” the cause of the condition. Additionally, determining whether an event was traumatic involves both subjective and objective elements, but the subjective element is paramount (see Atkins v British Columbia (Workers’ Compensation Appeal Tribunal), 2018 BCSC 1178 at para 78.) The objective question is only to determine if the event is “identifiable”.

A psychological injury which is caused by “stressors” (vs. “traumatic events”) must meet the “predominant cause” standard. This is a significant hurdle for workers with pre-existing psychological conditions who become disabled after work stressors, such as bullying or harassment. These conditions do not have to result in an injury immediately, stressors can make up the predominate cause of a condition that takes time to manifest or be diagnosed.

Section 135 of the WCA [Former Act, s. 5.1] also requires that a psychological condition be diagnosed as a mental disorder by a registered psychiatrist or psychologist.

Section 135 also provides that mental stress arising from a decision by the worker’s employer related to the employment (e.g. a change in job description or working conditions, or termination of employment) is specifically excluded from compensation. However, an employer may not communicate a management decision in any way it wants and communication that humiliates, intimidates, or amounts to bullying, harassment, threats or abuse may be beyond s. 135(1)(c) [Former Act, s. 5.1(1)(c)] protection.

Psychological injuries that result from interaction with WCB and the claims process are also not compensable (Noteworthy Decision: WCAT-2015-01459). Though they would not happen but for the workplace injury, they are too remote to be compensable. Exceptions may arise in special circumstances, e.g. where the Board has acted negligently, or in bad faith.

Section 135(2) of the WCA [Former Act, s. 5.1(1.1)] creates a rebuttable presumption for eligible occupations that a worker’s mental disorder is a reaction to one or more traumatic events arising out of and in the course of their employment. The presumption applies where the worker is:

• exposed to one or more traumatic events arising out of and in the course of the worker’s employment in an eligible occupation; and
• diagnosed by a psychiatrist or psychologist with a mental disorder that is recognized in the most recent DSM at the time of diagnosis, as a mental or physical condition that may arise from exposure to a traumatic event.

In making determinations regarding mental disorders, the Board must make both a subjective and objective analysis of the situation. Certain workplace interactions or events can, on the surface seem innocent, but within the context of the work environment and the employee constitute a stressor or series of stressors that can be seen as either significant or traumatic as described by policy item #C3-13.00.

In making this determination, a worker’s general characteristics and history are relevant. For example, an employee with past trauma related to a certain incident may find related stressors more aggravating. That being said, the worker’s concerns and complaints must still be grounded in reality.

The Act also defines an eligible occupation to mean the occupation of a correctional officer, emergency medical assistant, firefighter, police officer, or sheriff.

As of May 16, 2019, this mental health presumption was extended to emergency dispatchers and publicly-funded health-care assistants.

I. Section 145 Injury: Hearing Loss

Significant hearing loss caused by exposure to industrial noise in the course of employment is compensable. The worker must submit tests showing the loss of hearing and complete a special application form listing all employment and non-employment noise exposure. See ss. 145 and 198 and Schedule 2 of the WCA [Former Act, s. 7 and Schedule D].

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