Worker v. Employer, 2026 CanLII 41519

20260024

REPRESENTED by:

VIDEOCONFERENCE – FEBRUARY 2, 2026

HEARD by:

DATED:

FEBRUARY 4, 2026

ISSUE

The worker objects to the Occupational Disease & Survivor Benefits (OD&SB) Adjudicator decision dated January 25, 2024, denying entitlement to benefits for occupational fumes exposure.

BACKGROUND

On November 15 ,16, and 17, 2023, the worker was assigned to work in the soaker infeed area. During this period, she developed symptoms including a sore throat, sinus issues, and headache. These symptoms progressively worsened by November 17, 2023. The worker attributed her health issues to exposure from caustic fume leaks in the workplace. On November 17, 2023, the worker reported her exposure to fumes to the employer. She subsequently sought medical attention on November 21, 2023, to address her symptoms. At the time of the incident, the worker was employed as a packaging operator.

Initial entitlement to health care benefits was initially approved by the WSIB in November 2023. The employer objected to the entitlement decision, and provided additional information for review. Upon reconsideration, the Adjudicator rescinded the worker’s entitlement under this claim as per the decision letter dated January 25, 2024.

The worker, through her representative, objected to the decision dated January 25, 2024. The worker seeks entitlement to benefits for work-related caustic fumes exposure, and this is now the matter before the Appeals Services Division. As per the Respondent Form dated November 26, 2025, the employer confirmed they are not participating in this appeal.

AUTHORITY

Workplace Safety and Insurance Act (WSIA), 1997, as amended

Operational Policy Manual

Published

11-01-01 Adjudicative Process 11-02-02 Lost Time Claims

11-01-03 Merits and Justice

November 3, 2008

April 9, 2021

October 12, 2004

ANALYSIS

I have carefully considered all of the available information, legislation, relevant operational policies and testimony in reaching this decision. For the reasons that follow, I find the worker is entitled to benefits for occupational fumes inhalation.

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 and testimony in relation to the issue in dispute.

Worker Position

The worker testified that her pre-injury position as a packaging operator required her to work in various areas on a rotational schedule, changing stations every hour and taking breaks every four hours. She stated that the standard personal protective equipment (PPE) provided included wrist gauntlets, safety glasses, and safety shoes. There was no mention of any respiratory PPE being used. According to the worker, at the soaker infeed station, she was required to stand on a platform at the machine’s entry point. This station uses chemicals to clean beer bottles, specifically sodium hydroxide, which is commonly called “caustic” in the workplace. The tasks involved checking that all bottles are of the same type, removing and repositioning bottles, and resetting the system if a jam occurred.

The worker stated that, on November 15, 2023, she was assigned to the soaker infeed station, an area she had not worked in for a significant period. While working there, she developed sinus discomfort at the back of her throat and a mild headache. At the time, she did not pay much attention to these symptoms, attributing them to being unaccustomed to the area. The worker later stated that she was confident her symptoms were caused by exposure to caustic chemicals from the soaker. She mentioned that it is generally known in the workplace that the soaker machine is deteriorating, with frequent complaints and reports about its condition. When she worked in the same area on November 16, 2023, she noticed her symptoms worsened, as she experienced increased sinus irritation and a persistent headache.

On November 17, 2023, while working again in the soaker infeed area, the worker observed that her symptoms persisted. She noticed steam escaping from the infeed machine and saw that the industrial curtain, which is meant to exhaust fumes from the soaker, had been left open. She described the soaker machine as rusted and corroded, indicating significant wear and tear. The worker reported her condition to her manager, the soaker operator (A.B.), and safety representatives. The group inspected the soaker and identified several maintenance issues. During the inspection, A.B. discovered that caustic was leaking from the valve directly beneath the operator station at the soaker infeed. The worker noted that the industrial curtain was subsequently closed. She believed that the maintenance concerns she raised

would be addressed and repaired. After making her report, she was assigned to a different area and has not returned to work in the soaker infeed station since.

In her Worker’s Report of Injury/Disease (Form 6), completed on November 23, 2023, the worker stated that she developed a sore throat and sinus issues on November 15, 2023, while working at the soaker infeed station. She noted that she worked “more than normal” in that area on November 16, 2023, and her symptoms continued. The worker reported her symptoms of sore throat, sinus irritation, and headache to her manager on November 17, 2023. The worker provided the following statement on the Form 6:

I felt a sore throat/sinuses getting progressively worse through the week – Thursday November 16, 2023 I had to rotate every other hr at the soaker infeed. Thursday night I went home and felt a very sore throat/sinuses and headache. Friday morning I woke up feeling worse – I came to work and talked to some of coworkers about the fumes in the soaker area and how strong they were – I then contacted my Safety Rep [C.D.] and [E.F.] and reported to Manager [H.J.]. Some investigation done by [C.D.], [E.F.], [H.J.] uncovered some maintenance issues that may have contributed to the fumes – Exhaust [sic] curtains left open, several caustic leaks on machine, rusted corroded infeed area with caustic steam constantly leaking out. Just to name a few. I contacted my Dr immediately and set up an appointment for Tuesday November 21, 2023.

Employer Position

The employer completed the Employer’s Report of Injury/Disease (Form 7) on November 24, 2023. According to the report, the worker began experiencing symptoms on November 16, 2023, and notified the employer about her symptoms on November 17, 2023. The employer stated that an investigation into the matter was underway. It was confirmed that the worker missed three hours of her shift on November 21, 2023, in order to seek medical attention.

In correspondence dated December 18, 2023, the employer described the worker’s regular duties in the soaker area, which typically amount to approximately two hours per day. However, on the day of the reported exposure, the worker was assigned to this area for a longer period, with a maximum of four hours (working one hour on and one hour off). The worker had reported that the machine she was operating was malfunctioning and claimed that exhaust was being emitted from it. The employer responded by stating that the machine was not malfunctioning, as the maintenance team had completed its routine monthly inspection just the previous day.

The employer submitted the worker also mentioned that the protective curtain, which is generally kept closed, was open while she was working in the area. According to the employer, the curtain’s primary function is to prevent caustic from splashing on people passing by. The employer confirmed that the curtain was observed to be open and was closed after it was noticed. The employer also noted that several individuals were present in the area at the time, but no one else reported any issues related to fumes. Management received only one report regarding fume exposure, which came from the worker in question.

Air Monitoring Information

The record contains an Air Monitoring Study dated November 8, 2022, completed by R. Chanderdat, an independent industrial hygiene consultant. The air sampling study was completed for sodium hydroxide (caustic) during a typical production shift at the Line 4 Bottle Washer/Soaker Feed area on November 8, 2022. Long-term samples were collected for sodium hydroxide from the following locations: Filler Operator Desk, Washer Infeed – Lower Platform (on control panel), Soaker Infeed – Top Platform (on control panel), North Side Washer Doors (caustic check station), and Platform Above Soaker Reclaim (on beam at breathing zone level). The report noted the occupational exposure limit (OEL) for sodium hydroxide as outlined in Ontario Regulation 833 – “Regulation respecting Control of Exposure to Biological or Chemical Agents” is 2 mg/m³. The OEL is based on a ceiling exposure value (CEV), i.e. is the maximum airborne concentration of an agent to which a worker is exposed to at any time. The findings indicated the airborne sodium hydroxide levels for all five (5) samples were calculated to be less than 0.048 mg/m³ or less than 0.049 mg/m³ and below the 2 mg/m³ CEV.

A subsequent air monitoring study was completed by R. Chanderdat on November 22, 2023, following the worker’s symptom onset. Long-term samples were collected for sodium hydroxide in the following locations: Filler Operator Desk, Washer Infeed – Lower Platform (on control panel), Soaker Infeed – Top Platform (on control panel), North Side Washer Doors (caustic check station), Platform Above Soaker Reclaim (on beam at breathing zone level), and the OMNI Bottle Inspection Test Area. The report states, in part:

The area sample collected at the OMNI Bottle Inspection Test Area revealed an airborne sodium hydroxide concentration of 0.097 mg/m³ and below the 2 mg/m³ C. There is no long-term exposure limit or [time-weighted average limit] for sodium hydroxide.

Analytically no detectable (less than 40 µg) sodium hydroxide was found in the other five

(5) long-term area samples collected. Based on the analytical reporting limit (40 μg) and the volume of air collected, airborne sodium hydroxide levels for these five (5) samples were calculated to be less than 0.048 mg/m³ and below the 2 mg/m3 CEV.

Pertinent Evidence

The record includes documentary evidence indicating that, on November 14, 2023, a leaking gasket was identified in the #4 soaker hydro spray. This malfunction resulted in caustic fumes being expelled through the side of the observation window. Further entries in the same maintenance log show that, on November 17, 2023, there were complaints regarding caustic fumes on the mezzanine level of the soaker area. The issue was reported and subsequently inspected. During the inspection, it was noted that the curtain at the infeed was ajar, and it was then closed. It was also confirmed that the exhaust system was operating properly at that time.

The record contains an email dated February 1, 2024, from (T.R.), employer plumber, indicating a work order had been placed on November 21, 2023, to repair the packing on “L4 soaker comp#2 knife valve.” It was noted the work order had been closed on December 8, 2023, suggesting the work had been complete. The email states, in part:

l don't know if this work order was created for the leaks in question as I was not part of that conversation. All I know is that I was told a valve needed to be repaired so I made a work order and replaced the packing on Knife valve comp#2 L4 soaker.

The record contains an email authored by L.M. sent to the worker on February 7, 2024, stating the following:

I was the soaker operator on November 17^th, 2023 when [the worker] brought up a caustic fumes issue to management. [The worker] noticed a smell of caustic fumes in the air, and I was called to review the area. Our manager at the time [H.G.] and I monitored the area and found knife valve 1 leaking caustic when renovating as you see in the videos.

Medical Evidence

The worker testified that she contacted her doctor’s office on November 17, 2023, to book an appointment after experiencing symptoms. She stated that the earliest available appointment was scheduled for November 21, 2023. In the interim, the worker managed her symptoms with Motrin and allowed them to resolve naturally. She indicated that she did not require urgent medical attention, as her symptoms began to improve after she was removed from working in the soaker infeed area.

On November 21, 2023, Dr. J. Mailloux assessed the worker and completed a Health Professional’s Report (Form 8). According to the Form 8, the worker presented with headache, sore throat, and sinus pain, which were attributed to fumes exposure. While the worker was cleared to return to work, she was advised to avoid the soaker infeed area and any further exposure to caustic fumes.

The chart note from the November 21, 2023, visit indicated that the worker reported exposure to caustic fumes in the workplace. Reference was made to a Material Safety Data Sheet (MSDS) for Liquid Bril-Tak®, a product containing sodium hydroxide used for cleaning beer bottles in the workplace. The worker reported that she developed a sore throat, headache, and sinus pain while at work, which she associated with caustic fume exposure. The worker testified that she showed Dr. Mailloux the MSDS, stating she had obtained it from a safety representative at work.

Assessment of the Evidence

In order to establish initial entitlement to benefits, operational policy 11-01-01 states in part:

Five point check system

All decision-makers use the same criteria for ruling on initial entitlement to WSIB benefits. This system is known as the "five point check system."

An allowable claim must have the following five points:

an employer
a worker
personal work-related injury
proof of accident, and
compatibility of diagnosis to accident or disablement history.

With respect to the “five-point check system,” there is no dispute regarding the worker and employer relationship in this case. The issues to be determined is whether there is sufficient evidence of a personal work-related injury, proof of accident, and whether the worker’s diagnosis is compatible with the accident history.

The WSIB does not have specific policies related to caustic fume exposure. 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 to caustic fumes caused or significantly contributed to the development of the worker’s inhalation injury. If established, the above will generally be considered persuasive evidence that the worker’s employment made a significant contribution to the worker’s illness. A significant or material contributing factor is one of considerable effect or importance.

The worker developed symptoms of sore throat, sinus issues and headaches on November 15, 2023, which progressively worsened over the next several days. The worker attributes her symptoms to exposure to caustic fumes in the workplace, specifically in the soaker infeed area. The worker reported her symptoms to her employer on November 17, 2023, and she sought medical attention on November 21, 2023. She was diagnosed with fume exposure causing headache, sore throat, and sinus pain. The worker was advised to refrain from working in the soaker infeed area.

The employer maintains that entitlement to benefits is not warranted, arguing that there is no evidence of occupational exposure to caustic fumes and, therefore, the worker’s symptoms are not related to the workplace. The employer asserts that both the machinery and the exhaust system were functioning properly. However, the available documentary evidence does not support the employer’s position. The record shows that, on November 14, 2023, a soaker hydro spray had a leaking gasket, which resulted in caustic fumes being released. Additionally, on November 17, 2023, it was documented that the industrial curtain in the soaker area was found to be ajar. Although the issue was promptly corrected by closing the curtain, the fact that it was left open lends credibility to the worker’s statement that she was exposed to caustic fumes in the soaker infeed area.

Regarding the functionality of the soaker machinery, greater weight has been placed on the worker’s testimony, as her statements are corroborated by documentary evidence in the record. Upon inspection on November 17, 2023, L.M. confirmed that knife valve 1 was leaking caustic, and a work order was created to replace it, as further confirmed by T.R. These independent statements indicate that the soaker machinery was not functioning properly at the time and further support the worker’s claim of exposure to caustic fumes in the soaker infeed area.

The employer referred to the air monitoring study conducted on November 22, 2023, to support their position that the worker was not exposed to caustic fumes, as the study showed no elevated levels of sodium hydroxide. While the employer’s argument is noted, significant weight has not been placed on this study because it was conducted several days after the reported exposure. By the time the study was performed, corrective actions had already been taken, including the closing of the industrial curtain and the replacement of knife valve 1, as confirmed by the email from T.R. These actions likely addressed the concerns raised by the worker prior to the air monitoring study.

Upon reviewing the evidence, I find the worker experienced a personal, work-related injury due to caustic fume inhalation between November 15 and November 17, 2023. The record supports that machinery and the exhaust system were not functioning properly, as evidenced by the need to replace a leaking knife valve and the fact that the industrial curtain was left open. Proof of accident is established, as the worker experienced an immediate onset of symptoms, reported them to her employer, and sought medical attention promptly. Regarding compatibility, the medical opinion of Dr. Mailloux is accepted. Dr. Mailloux confirmed that the worker experienced symptoms consistent with caustic fume exposure, and the MSDS provided by the worker verified the presence of sodium hydroxide in the chemicals used at the soaker infeed. Dr. Mailloux advised the worker not to return to work in the soaker infeed area due to her symptoms.

In summary, the five point check system has been fully satisfied in this case. After reviewing all the evidence, I find there is sufficient and persuasive documentation to support that the worker’s employment-related exposures to caustic fumes likely made a significant contribution to her inhalation injury. The available evidence, including the worker’s testimony, corroborating documentary records regarding the malfunctioning machinery and open industrial curtain, and the medical opinion of Dr.

Mailloux, all support the occurrence of a workplace exposure. Based on the balance of probabilities, I am satisfied that the worker’s symptoms of headache, sore throat, and sinus pain are causally linked to her workplace environment and the identified caustic fume exposure. As such, I find that the worker is entitled to benefits for caustic fume exposure, in accordance with the applicable operational policy and the evidence presented in this case.

The worker’s absence from work to seek medical attention on November 21, 2023, is considered reasonable and appropriate. The employer confirmed the worker missed three hours from work on this date, as documented in the Form 7. Therefore, in accordance with operational policy 11-02-02, loss of earnings (LOE) benefits are approved for the missed work time on November 21, 2023. Any additional entitlement sought under this claim will be referred to the operating area for further adjudication.

CONCLUSION

I conclude the worker is entitled to benefits for caustic fume inhalation. The worker is entitled to LOE benefits for lost time incurred on November 21, 2023.

The worker’s objection is allowed.

DATED FEBRUARY 4, 2026

L. Mansueti

Appeals Resolution Officer Appeals Services Division