Elimination Substitution Engineering Controls
Elimination, substitution, and engineering controls are the top three layers of the hierarchy of controls, prioritized by WorkSafeBC and OSHA. Elimination removes the hazard entirely, substitution replaces it with a less hazardous alternative, and engineering controls physically change the workplace to prevent exposure, such as machine guards, barriers, or local exhaust ventilation. These are preferred over administrative controls or PPE.
In a Canadian manufacturing or shop-floor context, these controls are applied by design rather than worker behavior. Examples include using conveyors to eliminate manual lifting, substituting a less toxic solvent, enclosing noisy or dusty processes, installing point-of-use exhaust at welding stations, and separating pedestrians from forklifts with fixed barriers. WorkSafeBC requires substitution whenever practicable and engineering controls to keep airborne contaminants below exposure limits. These controls are more reliable than administrative controls as they do not depend on worker memory or supervision.
What is the regulatory basis for prioritizing elimination, substitution, and engineering controls?
WorkSafeBC and OSHA both mandate these as the preferred controls before administrative controls or PPE, based on the hierarchy of controls. WorkSafeBC requires substitution whenever practicable and engineering controls to maintain exposure limits, while OSHA defines engineering controls as workplace changes that reduce exposure at the source.
How are engineering controls implemented on a manufacturing floor?
Engineering controls involve physical changes like machine guards, isolation barriers, interlocked enclosures, wet methods for dust suppression, or local exhaust ventilation. Examples include enclosing noisy processes, installing point-of-use exhaust at welding stations, and separating pedestrians from forklifts with fixed barriers and marked lanes.
What are common compliance failures with these controls?
Common failures include skipping elimination/substitution and relying on PPE, neglecting maintenance of engineering controls like damaged guards or failed ventilation, and failing to document why substitution or engineering controls were not practicable, which violates WorkSafeBC requirements.