Time-weighted average

Hazards

• An average exposure calculated across a specified work period, commonly eight hours.

Controls

• Measure representative tasks and durations, include peaks and multiple sources, and compare with the correct standard.

Personal protective equipment

• Select task-specific PPE only after hazards and higher-order controls have been evaluated.

Regional considerations

• Applicable law, permits, collective agreements, venue rules, and qualified-person decisions take precedence.

In practice

Measure representative tasks and durations, include peaks and multiple sources, and compare with the correct standard.

Explore related entries

• Permissible exposure limit
• Short-term exposure limit