Ionizing radiation is a form of energy that removes electrons from atoms, creating charged particles called ions. Ionizing radiation comes from natural sources like cosmic rays and radon gas. It also comes from human-made sources such as x-ray machines, nuclear reactors, and equipment like industrial radiography.

Ionizing radiation can cause serious health effects. Employers need to manage exposure to protect workers.

How workers are exposed

Exposure can occur externally from radiation sources. It can also occur internally by inhaling or ingesting radioactive materials or substances such as radon.

Workers may encounter ionizing radiation in the following types of workplaces:

• Health care (e.g., radiation therapy, diagnostic imaging like x-rays and CT scans)
• Research and labs (e.g., radioactive materials)
• Manufacturing plants, pipelines, construction sites, and other industrial settings (e.g., non-destructive testing, nuclear density gauges, analytical equipment)
• Buildings with high radon levels, especially in basements or poorly ventilated areas

The risks for workers

Ionizing radiation can cause short-term health effects such as skin burns and hair loss. At higher doses it can cause radiation sickness.

Long-term effects of exposure include genetic damage. In addition, the International Agency for Research on Cancer has classified ionizing radiation as a carcinogen (Group 1), meaning it causes cancer in humans.

Pregnant workers are at higher risk because radiation can harm the developing fetus.

How to protect workers

Employers must ensure that workers’ exposure to ionizing radiation is kept as low as reasonably achievable below the exposure limits set out in section 7.19 of the OHS Regulation.

The most effective way to reduce the risk to workers is to eliminate the source of radiation exposure. If that’s not possible, there are other risk controls to use.

The following table outlines examples of risk controls. Which controls you apply will depend on the level and type of exposure in your workplace.

If a worker exceeds or may exceed an effective dose for ionizing radiation in the workplace above the action level of 1 millisievert (mSv) per year, employers must have an exposure control plan (ECP) in place. The ECP must include safe work procedures, training, and radiation surveys.

See OHS Guidelines G7.20(1)-1 to G7.20(2) for more details about controlling exposure. In addition, many industry health and safety associations and colleges of practitioners (e.g., dental, chiropractic, veterinary) have guidance that may apply to your workplace.

Jurisdiction responsibilities

Radiation safety in B.C. involves multiple authorities:

• WorkSafeBC administers the OHS Regulation. Part 7 of the OHS Regulation covers radiation safety requirements. Employers or workers can contact WorkSafeBC with questions about radiation safety or to report an incident.
• Health Canada regulates the sale, lease, and import of radiation-emitting devices under the Radiation Emitting Devices Act and its associated regulations.
• The National Dosimetry Services (NDS) is a centralized radiation dose record system operated by Health Canada and contains dose records of all monitored radiation workers in Canada.
• The Canadian Nuclear Safety Commission (CNSC) regulates nuclear substances, high-energy x-ray machines, and facilities.
• Health authorities and independent regulatory bodies, including the College of Physicians and Surgeons of British Columbia, provide requirements and guidance on radiation protection from a public health perspective.

See OHS Guideline G7.18 for more information about jurisdiction.