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Environmental and Workplace Health

Workplace Control Measures

Quick Facts

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Workplace controls are measures used to prevent or minimize workplace hazards. General information on control measures is provided in the Exposure Controls section of the Material Safety Data Sheet (MSDS). Employers must evaluate product hazards in their workplace and determine the specific controls for their safe use.

Workplace control measures can be organized into a hierarchy of controls. The controls are itemized according to their effectiveness in reducing hazards.

You should first consider measures that would eliminate or reduce the hazard in the workplace, or isolate hazards away from workers. Next you would consider controls, such as work practices, which are also important to reduce potential exposures to hazardous materials in the workplace. Finally, personal protective equipment (PPE) protects the workers from hazards not reduced by other measures.

Employers should choose the hazard control measures starting from the top of the hierarchy of controls that are suitable for the situation. Frequently several control measures are used.

Hierarchy ofWorkplace Controls

1. Elimination

Removing a hazardous material from use in the workplace so no further exposure is possible.

Example: Use lead-free paints.

2. Substitution

Replacing a very hazardous material with a less hazardous one.

Example: Replace organic solvents with water-based products. See the Substitution WHMIS Fact Sheet for more information.

3. Modification

Changing a process or procedure to eliminate or reduce emissions.

Example: Replace a spray-paint operation with a paintdip or "airless" spray operation.

4. Containment

Using physical barriers or containment to separate hazardous materials or environments from work areas.

Examples: Closed reaction system; paint-spraying booth; glove box.

5. Ventilation

Removing or diluting hazardousmaterials in the air by removing the contaminated air and replacing it with outside air.

Local exhaust ventilation is most effective because it captures the contaminated air at the source and removes it from the work environment. It is very effective when there are point sources of emissions. Dilution ventilation reduces hazardous materials in the air by dilution with outside air and so is less effective.
Examples: fumehoods and welding exhaust units are types of local exhaust systems.

6.Work Practices

Work practices are procedures that limit worker exposure by reducing exposure times or keeping workers away from contaminants. The following are some common work practices:

Scheduling maintenance or high exposure operations at off-peak times when few workers are present (e.g. weekends, evenings).

Good Housekeeping practices such as maintaining a clean, clutter-free workplace help reduce potentially hazardous exposures for workers.

Example: Regular cleaning to remove scrap and prevent accumulation of hazardous materials on work surfaces.

Personal Hygiene Practices, Policies and Procedures that help prevent exposure to hazardous materials by skin contact, ingestion or inhalation.
Examples: Launder work clothing separately; do not smoke or eat in work areas; wash hands thoroughly after handling materials.

There should be written, standardized safe operating procedures for all work with hazardous materials. These procedures should be based on good practices for work with hazardous materials.

7. Personal Protective Equipment (PPE)

Equipment such as gloves and goggles are used to protect workers from hazards. PPE is less effective because the hazard is still present and workers are not protected if the PPE fails. PPE should only be used if necessary after other control measures are implemented or if other controls are not practicable. See the Personal Protective Equipment WHMIS Fact Sheet for more information.

Remember: Employees must be trained in all of the control measures used in their work areas.

Prepare for emergencies...
Know the procedures to follow in the event of a breakdown in control systems.