Scleroderma & Occupational Exposure to Silica Dust


The WSIB recognizes scleroderma resulting from occupational exposure to silica dust as an occupational disease pursuant to subsection 2(1) of the Workplace Safety and Insurance Act.



The following is persuasive evidence that a worker's scleroderma is due to the nature of the employment

  • the scleroderma, as defined below, is diagnosed by a licensed internist or rheumatologist, and
  • the worker was exposed to substantial levels of silica dust in the employment before the diagnosis of scleroderma is made.

The level of exposure to silica dust is considered "substantial" when it is continuous and long-term, or when it is of short duration but intense.

Scleroderma has been observed among workers occupationally exposed to silica dust for cumulative periods ranging from as few as 3 years to as many as 43 years.

Case reports indicate that workers diagnosed with scleroderma have been exposed to extremely high levels of silica dust. Such exposure is exemplified by mining, or sandblasting in an enclosed space.

Occupational settings and processes that may expose workers to substantial levels of silica dust are (1):

  • hardrock mining
  • sandblasting
  • manufacture of abrasives, grinding and scouring compounds, moulds for castings, fillers for paints and mastic, glass, optical equipment, pottery, ceramics, electronic components, fibreglass, radio and TV components
  • brick and cement work
  • buffing, metal polishing and grinding
  • foundries (ferrous and non-ferrous)
  • cutting granite
  • quarries
  • steel plants
  • stone and clay making.

Occupations not listed may also expose workers to substantial amounts of silica dust.

    1. Adapted from Ministry of Labour: Designated Substances in the Workplace: A guide to the Silica Regulation, 1986


Scleroderma -- is sometimes called systemic sclerosis. It is a type of connective tissue disorder. Diagnosis is recognized if the case is characterized by (2)

  • proximal scleroderma

    skin changes suggestive of scleroderma which appear near the finger and wrist joints, as well as on other parts of the extremities, face, neck, or trunk of the body. These changes usually appear symmetrically on both sides of the body and almost always include skin changes on fingers and toes


two of the following

  • sclerodactyl - skin changes suggestive of scleroderma, limited to fingers and toes
  • digital pitting of fingertips or loss of substance from the finger pad -- depressed areas at tips of digits or loss of digital pad tissue
  • bilateral basilar pulmonary fibrosis -- x-ray evidence of a bilateral pattern of linear or linear-nodular densities in the lower lung which are not due to primary lung disease.
  1. Adapted from Subcommittee for Scleroderma Criteria of the American Rheumatism Association Diagnostic and Therapeutic Criteria Committee. Preliminary criteria for the classification of systemic sclerosis (scleroderma). Arthritis and Rheumatism 23(5):581-590, 1980.

Determining the degree of permanent impairment

The clinical course of scleroderma varies from case to case and depends on such factors as age, sex, the extent and location of skin disease, and whether internal organs are involved.

When the worker has achieved maximum medical recovery (see 11-01-05, Determining Maximum Medical Recovery (MMR)), a review of the medical information on file is conducted to determine the degree of the worker's permanent impairment. If the existing medical information in the claim file is insufficient to determine the degree of the worker's impairment, the WSIB requests additional medical information from the worker or worker's physician(s). If the information is still insufficient, the WSIB will arrange for a NEL medical assessment to obtain the necessary information. For more information see 18-05-03, Determining the Degree of Permanent Impairment. The WSIB takes into consideration the body systems that may be affected by scleroderma when conducting this review.

These body systems include the skin, respiratory, cardiovascular, digestive, urinary, and musculoskeletal systems.

The observed impairments in these systems are "combined" using the Combined Values Table to reach whole person ratings as specified in the American Medical Association's Guides to the Evaluation of Permanent Impairment, 3rd Edition (revised), (AMA Guides).

Application date

This policy applies to all accidents. Benefits are payable from the date of accident, which is the date of diagnosis of scleroderma, or the first date that related symptoms are medically documented, whichever is earlier.

Document History

This document replaces 16-02-19 dated October 12, 2004.

This document was previously published as:



Legislative Authority

Workplace Safety and Insurance Act, 1997, as amended
Sections 2(1), 15, 47, 119, 121, 124

Minute History

Board of Directors
#2, April 1, 1993, Page 5633
#8, June 10, 2004, Page 6621


#16, May 26, 2008, Page 461