20260022

REPRESENTED by:

HEARD by:

DATED:

MARCH 9, 2026

The worker objects to the Occupational Disease & Survivor Benefits Program (OD&SBP) Adjudicator decision dated January 12, 2024, which denied entitlement to benefits for Asthma-Chronic Obstructive Pulmonary Disease Overlap Syndrome (ACOS).

The worker started having respiratory problems in 2012, and they were diagnosed with Chronic Obstructive Pulmonary Disease (COPD) by Dr. J. Lockyer, a pulmonologist, in January 2013. The claim was initiated based on the Worker’s Report of Injury/Disease (Form 6), dated February 25, 2013. The report noted the worker had developed severe lung disease, resulting in only 37 per cent lung function. They had been employed from 1971 to 2012 (~42 years) working for various employers in Ontario, Alberta, Saskatchewan, Quebec, and Newfoundland, holding different positions.

The Adjudicator requested the worker’s previous medical records and employment history and obtained a statement from the worker’s co-worker. The case was then referred to the WSIB Occupational Hygienist (OH) for an exposure assessment.

On September 11, 2013, the WSIB OH completed the exposure assessment, reviewing the worker’s exposure to respirable dust and airborne emissions during their employment. The assessment estimated the worker’s cumulative respirable dust exposure over 28 years in the blown film extrusion area in the plastics company was likely less than 10 mg/m³-years. Alongside dust exposure, the worker may have encountered low levels of airborne process emissions from extruding plastics, including organic vapours (such as aldehydes, ketones, carboxylic acid), and ozone.

On September 13, 2013, the adjudicator denied initial entitlement for COPD. The decision was based on the determination that the worker’s cumulative occupational exposure was not a significant factor in the development of their COPD. It was also concluded that the worker’s substantial smoking history, estimated at more than 60 pack years, was the most significant contributing factor to their COPD. An Appeals Resolution Officer (ARO) decision dated August 3, 2018, denied entitlement to benefits for COPD. The ARO determined the evidence failed to demonstrate the worker’s occupational exposures to dust and airborne process emissions made a significant contribution in the development of COPD.

Dr. Lockyer subsequently diagnosed the worker with ACOS, and an OH review was completed by an occupational health clinic (OHC). The worker, through their representative, requested entitlement to benefits for ACOS, citing the worker’s occupational exposures significantly contributed to the development of this condition.

The operating area reviewed the new evidence and obtained another opinion from a WSIB OH and an Occupational Medical Consultant (OMC). The decision letter dated January 12, 2024, communicated there was no entitlement to benefits for ACOS on the basis the evidence failed to demonstrate the occupational exposures to vapours, gases, fumes and emissions materially contributed to the development of ACOS. The worker objected to the denial of benefit entitlement for ACOS, and this is now the matter before the Appeals Services Division.

Section 2(1) and 15 of the Workplace Safety and Insurance Act (WSIA), 1997, as amended Schedules 3 & 4

Operational Policy Manual

Published

11-01-03 Merits and Justice

October 12, 2004

Adjudicative Advice Document: Chronic Obstructive Pulmonary Disease April 2001

I have carefully considered all of the available information, legislation, relevant operational policy, and support document in reaching this decision. For the reasons that follow, I find the worker is entitled to benefits for ACOS.

It should be noted my review and assessment does not include an all-inclusive summary of all the evidence submitted to the record, and there has been no attempt to reference every document in the claim file. I have included a summary of the pertinent evidence submitted to the record in relation to the issue in dispute.

Employment and Exposure History

On September 11, 2013, a WSIB OH exposure assessment was completed. The assessment included a review of the worker’s potential occupational exposures to respirable plastics and plastic emissions while they were employed by a plastics manufacturer from 1978 to 2006 (28 years). The OH exposure assessment indicated the worker’s cumulative respirable dust dose was likely less than 10mg/m³-year

during their 28 years in the extrusion area. The worker was also potentially exposed to low levels of airborne process emissions, such as aldehydes, ketones and carboxylic acid and ozone.

An undated OHC report was submitted to the record outlining several deficiencies in the September 2013 WSIB OH exposure assessment. The OHC OHs submitted the September 2013 OH exposure assessment limited their review to agents of interest as it pertained to COPD; however, it did not account for potential exposures as it related to ACOS. They criticized the WSIB OH exposure assessment of completing a review based on an incomplete work history and underestimating the worker’s occupational exposures. The report indicated the worker was exposed to many lung irritants and chemicals during their career, including formaldehyde, acetaldehyde, acid fumes, plastic smoke, ozone, asbestos, wood dust, diesel exhaust, isocyanates, and other airborne irritants. It was noted the worker worked with these substances for various periods over 28 years. The amount of dust they breathed in at work was underestimated. Their exposure likely exceeded 10 mg/m³-years and was probably at least 30 mg/m³-years. The report indicated the worker’s exposure to various harmful substances at work was greater than officially reported, and the assessment used for their lung disease diagnosis missed important details.

The operating area acknowledged the worker’s full employment history, and all the relevant occupational exposures were not considered in the initial WSIB OH exposure assessment dated September 11, 2013. At that time, only the worker’s Ontario employment and related exposures were considered – 1978 to 2006 (28 years) in the OH review. It was noted the worker’s cumulative inorganic dust exposure was underestimated given the exclusion of the worker’s employment from 1971 to 1977, and 2007 to 2012.

Early employment (1971-1977)

Worked as a labourer and electrical helper with several employers, including short-term and seasonal jobs.
Employer A (1971): Performed general contract cleaning; specific job details unknown.
Employer B (1972/1973): Deciphered messages; also did manual cleaning at a hump yard for 8-9 months, including cleaning around towers and rail hub.
Small electrical companies (1973/1976): Operated copper wire rewinding of electrical core motors; cores cleaned and treated, burning/baking done at night (not during their shifts); no recall of fumes, smoke, or metal soldering.

Employer C (1974-1976)

Worked as electrician’s helper on an assembly line building trailers and mobile homes.
Responsible for electrical wiring, installing switches, lights, and panels.
Did not do soldering, spray painting, or use glues/adhesives.
Spray foam insulation used in the plant (described as “yellowish” with strong smell); spraying occurred about twenty feet from their workstation.

Employer D (1977, three weeks)

Installed insulation (believed to be asbestos) on pins inside boilers and secured it with chicken wire.

Employer E (1977-1978)

Worked as a roughneck for 5-6 months, drilling pipes and capping them.
No recall of dust exposure; worked during winter.

Employer F (1978-2006)

Company specialized in plastic film bag and bottle production.
Most exposure on polyethylene film air-blown extrusion line.
Did not work in the laminating department.

Employer G (2007-2010)

Carpenter helper: tasks included cutting wood framing, grading basements, raking, and shovelling gravel.
Did not use cement/concrete; lumber was spruce, pine, or fir.
Used circular saw intermittently.
Denied exposure to spray foam insulating.

Employer H (2010-2012)

Performed framing carpentry and general labour.
Denied exposure to diesel exhaust, heavy equipment, asphalt, plumbing, or soldering.
Graded basements; intermittently handled fiberglass insulation (about once a month).

The WSIB OH exposure assessment report dated September 18, 2025, indicated the review would focus on the worker’s potential cumulative exposures to the following occupational agents during the years 1971 to 1977 and 2006 to 2012:

Respirable Particulate Matter (RPM) including asbestos, silica, and strong irritants such as sulphur dioxide, oxides of nitrogen, fluorides, chlorine, ozone, formaldehyde, toluene diisocyanate and diesel exhaust.
Additional agents of interest relevant to occupational asthma The OH exposure assessment determined the following:

RPM exposure

Highest daily average exposure likely occurred while working at Employer F before local exhaust installation (pre-1982), with additional intermittent exposure as a carpenter/labourer (2007-2012) during sawing and cleaning tasks.
Possible indirect exposure due to proximity to other trades during construction/assembly tasks with Employer C (1974-1976) and as a carpenter (2007-2012).
Cumulative RPM exposure over 35 years (1971-2012) estimated to be less than or approaching 23 mg/m³-years, based on available information and worst-case assumptions.

Asbestos exposure

Highest exposure likely occurred during a 3-week period insulating boilers at Employer D, with a daily average greater than 1 f/cc.
No significant direct handling of friable asbestos-containing materials (acm) outside this period.
Possible minor exposure as an electrician’s helper with Employer C (1974-1976) from handling or cutting asbestos-sheathed wiring or drilling into asbestos board (estimated at 0.01–0.4 f/cc, not a major job component).
Occasional low-level exposure possible during cleaning tasks or proximity to other trades at Employer F (1978-1985), likely less than 0.1 f/cc daily average or trace to low compared to repair trades.

Silica exposure

Possible intermittent low-level exposure while roughnecking (6 months), as a labourer (1972-1973), or as a carpenter (2007-2012) from shovelling gravel, grading basements, or proximity to other trades.
Expected daily average exposure less than 0.03 mg/m³.

Irritants and asthma agents

Probable exposure to isocyanates or formaldehyde-based insulation overspray and possible skin contact with contaminants at Employer C (1974–1976).
At Employer F (1977–2006), potential routine airborne and skin exposure to dehp phthalates, and intermittent peaks of ozone (0.01–0.1 ppm) and formaldehyde (0.002–0.04 ppm, with peaks up to 9 ppm) from plastic fumes.
As a carpenter (2007–2012), moderate softwood dust exposure and intermittent formaldehyde peaks (less than 0.06 ppm).
Possible intermittent to routine diesel exhaust exposure as a roughneck (Employer E, 6 months) and intermittently as a labourer (9 months), with daily average exposure less than 25 μg/m³ (low to moderate compared to rail construction or heavy equipment workers).

Medical Evidence

The record indicated the worker worked at a plastics factory for 28 years, where they were exposed to dust, fumes, and chemicals. The worker had a long smoking history (about 50 pack years) and quit smoking around 2011.

Initial lung function tests in 2012 showed significant airway obstruction, with some improvement after medication. Dr. Lockyer indicated in the consultation report dated January 10, 2013:

[The worker] currently works with Employer H Homes and before this he worked with another construction company and he worked at a plastics factory in City A for twenty-eight years. He went from working on the floor to being a supervisor position and this place was full of fumes and we known [sic] in plastics factories certain chemicals such as Isocyanide is present and this is certainly at risk for asthmatics of causing occupational asthma, work exacerbated asthma and it is even possible that he has lung disease from this exposure.

Dr. Lockyer diagnosed the worker with obstructive lung disease from smoking and reversible components consistent with asthma. Dr. Lockyer continued to follow the worker, and prescribed medications for symptom management.

Dr. Lockyer submitted a report dated May 25, 2016, confirming the worker had chronic COPD of a severe nature. Dr. Lockyer reiterated they were of the opinion that a large portion of the worker’s lung disease was owing to their smoking. However, they also indicated the worker’s occupational exposures could have exacerbated or accelerated the disease process. By December 2016, the worker’s lung function remained stable but still poor. Physical exams showed over-inflated lungs, reduced lung movement, and poor air flow at the bases, with scattered crackles. A chest x-ray showed changes consistent with emphysema. In May 2018, the worker was diagnosed with severe obstructive airway disease and possible emphysema. It was believed these conditions were likely due to both their long history of smoking and significant work-related exposures.

Dr. Lockyer submitted a report dated March 30, 2023, indicating the worker was diagnosed with severe ACOS. Dr. Lockyer indicated that given the severity of their disease, young age of diagnosis and known occupational exposures to thermal plastics, it was their opinion that occupational exposure “was a likely contributing factor to the severity of his condition.”

Dr. B. McGoveran, OMC, reviewed the record on December 6, 2023. It must be noted Dr. McGoveran did not assess or treat the worker at any time. Dr. McGoveran was asked to provide a medical opinion with respect to compatibility of COPD and workplace exposures. The OMC surmised the worker’s COPD was overwhelmingly related to their significant smoking history rather than by any occupational exposures. Dr. McGoveran indicated ACOS was the most appropriate diagnosis for the worker.

Following receipt of the OHC report and the OH exposure assessment dated September 18, 2025, Dr. V. Spilchuk, OMC, reviewed the record on October 29, 2025, and provided an opinion with respect to this case. It must be noted Dr. Spilchuk did not assess or treat the worker at any time. The OMC had the opportunity to review the entire medical record as well as the hygiene assessments completed OHC and WSIB. Dr. Spilchuk surmised it was not possible to confidently rule out occupational exposures as having at least some role in exacerbating or accelerating the ACOS diagnosis. While it was noted the worker’s smoking history was the most relevant risk factor, it was not possible to rule out occupational exposures to vapours, gases, dusts, and fumes (VGDF) as having at least a minor, but relevant contribution to the ACOS diagnosis.

Assessment of the Evidence

While the WSIB has a specific policy pertaining to COPD in smelter workers (operational policy 16-02-14), there is no specific policy for ACOS in relation to other workers or work environments. When the condition or disease claimed is not listed in the Schedules and there is no specific WSIB policy, the decision is rendered based on the merits and justice of the individual case in accordance with the general provisions of the Act, as indicated in operational policy 11-01-03, which states, in part:

Decisions related to occupational disease

When determining entitlement to a disease claim, a decision-maker considers the worker’s clinical condition and exposure at work, the up-to-date clinical and scientific information, any pertinent non-occupational factors, and all of the relevant policies.

Entitlement to WSIB benefits and services is determined based on the merits and justice of the individual claim. It must be established that it is more probable than not the worker’s employment and/or exposure history caused or significantly contributed to the development of the medical condition for which benefits are being claimed. As such, the question to be determined is whether the workplace exposures caused or significantly contributed to the development of the worker’s ACOS. If established, the above will generally be considered persuasive evidence that the worker’s employment made a significant or material contribution to the worker’s illness. A significant or material contributing factor is one of considerable effect or importance.

With respect to COPD claims, an Adjudicative Advice Document was created in 2001 which provides important features of the scientific review on COPD and inorganic dusts and provides information on dust exposure assessment, disease description, clinical assessment, and non-occupational risks.

The Adjudicative Advice Document indicates the epidemiological evidence suggests an association between the development of COPD and exposure to respirable particulates and/or respiratory irritants. The epidemiological evidence suggests that exposure to high intensity respirable dust over a prolonged period of time is necessary to show significantly increased rates of impairment due to COPD. Short-term high intensity exposures can produce the same risk for COPD as compared to long duration low-level exposures. The literature indicates significant risk for COPD for workers with average intensity of respirable dust/fume exposure of 2mg/m³ (range of 0.89mg/m³ to12mg/m³) and an average exposure duration of 25 years.

I have considered the following factors as guided by the COPD Adjudicative Advice Document:

Confirmed diagnosis of COPD
The commencement of COPD symptoms 30 to 40 years after first exposure (COPD resulting from dust and fume exposures do not generally appear until after middle age)
Non-occupational risk factors
Prolonged employment in occupations/industry groups at risk for dust/fume exposures
Prolonged periods of exposure to high intensity respirable dust, fumes, diesel exhaust
Evidence of cumulative exposure to respirable dust/fume of 40-50mg/m³-years or more
Potential additional impact from long-term exposure to respiratory irritants such the following gases or vapours: sulfur dioxide, oxides of nitrogen, fluorides, chlorine, ozone, formaldehyde and toluene diisocyanate

The worker representative submitted the worker is entitled to benefits for ACOS on the basis their occupational exposures significantly contributed to the development of this condition.

With respect to occupational exposures, the WSIB occupational hygiene exposure assessment dated September 2025 indicated the worker’s cumulative respirable dust exposure was estimated at 23 mg/m³-years. The OHC assessment provided a slightly higher estimate, totaling 30 mg/m³-years. Both estimates are below the threshold of 40 to 50 mg/m³-years indicated in the COPD Adjudicative Advice Document.

While the worker representative acknowledges that the exposures are below the COPD Adjudicative Advice threshold, they referenced prior Workplace Safety and Insurance Appeals Tribunal (WSIAT) decisions. These decisions have clearly established that the COPD Adjudicative Advice Document is not intended to serve as a rigid or absolute threshold for determining entitlement to COPD benefits.

I fully support the worker representative’s position, as relying strictly on the threshold would disregard the broader context and the nuanced findings of the case-specific evidence. Importantly, this case is being reviewed for entitlement to ACOS rather than solely COPD. Given this, I place less emphasis on the COPD Adjudicative Advice Document guidelines, as they are not directly applicable to ACOS. The unique clinical and exposure circumstances in ACOS warrant a more flexible and case-specific approach to entitlement rather than strict adherence to the COPD threshold requirements.

The worker representative pointed to the medical opinions provided by the worker’s treating physicians, who were of the position the worker’s occupational exposures materially contributed to the development and/or acceleration of their lung disease. In addition, it must be noted Dr. Spilchuk was also of the position the worker’s occupational exposures made a material contribution to the development of ACOS. The OMC states, in part:

It is not possible to confidently rule out occupational exposures as having at least some role in exacerbating/accelerating his ACO diagnosis. Though his smoking history is likely the most relevant risk factor, it is not possible to rule out occupational exposures to vapors, gases, dusts and fumes (VGDF) as having at least a minor, but relevant contribution [emphasis added] to the ACO diagnosis.

The OMC further states, in part:

ACO is a relatively newly recognized respiratory condition, with proposed diagnostic criteria first provided by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) only in 2015. There is therefore a relative dearth of occupational literature specifically looking at ACO, and this is acknowledged as being a diagnosis that can cause adjudicative confusion, given that asthma and COPD, in spite of having potentially similar clinical presentations, are treated differently from a causal perspective. However there is at least some evidence to support that exposure to vapours, gases, dusts and fumes (VGDF) is an independent risk factor for the development of ACO, though the magnitude of risk remains obscure. I also note that it was documented in the letter from his specialist dated March 25, 2024, that he had asthma symptoms in childhood, and did not report worsening of respiratory symptoms during work, which would argue against a significant asthma component to the occupational contribution to ACO, since acute respiratory symptoms (e.g. cough/wheeze at the time of exposure or shortly after) from exposure to a trigger is a cardinal feature of asthma, and was not present here during exposure, further supporting the COPD component is more likely to be work-related than the asthma component.

The OMC further states, in part:

Taken together, the worker's smoking history is the most relevant risk factor for his ACO diagnosis, with underlying asthma an additional factor. Though workplace exposures were not documented to have exacerbated his asthma at the time of exposure, it is not possible to rule out at least some minor contribution to his ACO diagnosis (particularly the COPD component) on the basis of sustained occupational exposure to RPM and VGDF, particularly during work at the plastics plant.

The medical opinion clearly states that it is not possible to confidently rule out occupational exposures as having played at least some role in exacerbating or accelerating the worker’s ACOS diagnosis. Although the worker’s smoking history is acknowledged as the most significant risk factor, the opinion emphasizes that exposures to VGDF in the workplace likely made at least a minor but relevant contribution to the development of ACOS.

Given this medical evidence, it would not be reasonable to dismiss the impact of workplace exposures simply because they may not be the primary cause. The opinion highlights that even a minor contribution from occupational exposures is relevant and should be considered material in the context of occupational disease entitlement. This aligns with the principle that workplace exposures need not be the only or main cause; it is sufficient if they have materially contributed to the condition. The WSIB has consistently recognized that material contribution from occupational exposures, even when other significant risk factors are present (such as smoking), may establish entitlement. The medical opinion provided meets this standard by acknowledging a relevant contribution from workplace exposures. Based on the above, I am satisfied that there is sufficient evidence to conclude that the worker’s occupational exposures, on a balance of probabilities, materially contributed to the development and/or progression of ACOS.

CONCLUSION

I conclude the worker is entitled to benefits for ACOS. The worker’s objection is allowed.

DATED MARCH 9, 2026

L. Mansueti

Appeals Resolution Officer Appeals Services Division

Worker v. Employer, 2026 CanLII 41521

Case Summary

Employment and Exposure History

Medical Evidence

Assessment of the Evidence

CONCLUSION

DATED MARCH 9, 2026