Chronic Obstructive Lung Disease, Sulphur Dioxide and Particulates Exposure (Smelter Workers)


Chronic Obstructive Lung Disease (COLD) in smelter workers is accepted as an occupational disease under sections 1(1)(n) and 122 of the Workers' Compensation Actas peculiar to and characteristic of exposure to Sulphur Dioxide (SO2) and particulates.


Acceptance of a claim is dependent on objective medical evidence of COLD and impaired pulmonary function.

A diagnosis of primary bronchiectasis, chronic upper respiratory disease, or primary asthma without the presence of COLD is not considered an acceptable basis to claim under this policy.

Entitlement criteria

Based on medical studies, claims for COLD with impairment shall be favourably considered when all of the following circumstances apply.

Nature of exposure

A clear and adequate history of exposure to any smelting process involving the production of sulphur dioxide and particulates as a significant by-product of the process must be established. This includes roasting, smelting, converting of metallic ores, and the secondary production of sulphuric acid.

Intensity of exposure

Sulphur dioxide exposure is established when levels of more than 5 parts per million (5 p.p.m.) are recorded repeatedly over the exposure period.

Duration of exposure

A minimum of 20 years established exposure.

Inception period (latency)

A minimum of 20 years from the date of first exposure to the date of diagnosis.

Cessation interval

Where the cessation of risk is less than 5 years to the development of clinically disabling COLD, the presumption of Sulphur Dioxide effect applies.

Information required

In order to adjudicate a claim, the following forms are completed and submitted

Pulmonary function studies must be obtained from the treating agencies.

Where there is medical compatibility between the disability and exposure, and all entitlement criteria are met, the claim is allowable.


Date of injury prior To April 1, 1985

If the date of injury is prior to April 1, 1985, and the worker was employed in the exposure employment at the time the diagnosis was made (or an earlier date if approved by the WSIB), earnings for the year immediately prior to the date of diagnosis are used.

Date of injury from April 1, 1985 to January 2, 1990

The nominal rate is used if the date of injury is on or after April 1, 1985.

Comparable earnings

If the worker is no longer employed in the exposure employment, comparable earnings [section 122(6) in the 1980 Workers' Compensation Act for a worker doing the same job for the same employer, for the year immediately prior to the date of diagnosis are used.

Temporary total disability

In the absence of a permanent disability award under s.45(1), temporary total disability benefits under s.40(1) of the 1980 Workers' Compensation Act are not payable for periods of acute pulmonary disease except during

  • the definitive medical investigation in order to confirm the diagnosis, or
  • active treatment for the disease itself.

Temporary total disability benefits may be paid in established claims for permanent disability. Subject to appropriate medical evaluation, payment will be made for periods of disability due to acute lower respiratory illness.

The temporary total disability basis is used to establish the permanent disability basis. For more information, see 18-07-04, Calculating Permanent Disability Benefits.

Temporary partial difference

If the worker is requested to change employment, which is medically authorized and approved by the WSIB, entitlement exists for payment if there is a wage loss. To determine a wage loss,

  • the temporary total disability wage basis is compared with the worker's present wage, and
  • payment is granted until no difference exists, or a pension is awarded.

Dependency benefits

In the case of death, the decision maker determines whether the cause of death was Chronic Obstructive Lung Disease.

Application date

This policy applies to all decisions made on or after September 14, 2021 for all injuries before January 2, 1990.

Document History

This document replaces 16-02-14 dated October 12, 2004.

This document was previously published as:
04-04-17 dated November 1989.


Legislative Authority

Workers' Compensation Act, R.S.O. 1980, as amended
Sections 1(1)(n), 122


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