Work Capabilities: Definitions and How to Use Them

This page explains standard terms used by WCB and health care providers when planning treatment and return to work. It is written for service providers, and it can help employers and supervisors plan safe transitional duties.

Transitional work

Transitional work means temporarily tailoring duties to the worker’s current abilities—whether that’s modified work (tweaking parts of the regular job) or alternate work (assigning different tasks) during recovery.

Learn more about transitional work.

Work classifications

These 5 classifications describe the physical effort a job requires. Health care providers use them on WCB forms to match abilities with tasks in treatment and return-to-work plans.

Sedentary work

  • Lift up to 4.5 kg (10 lb) occasionally
  • Mostly sitting, brief standing, or walking

Light work

  • Lift up to 9.1 kg (20 lb) occasionally
  • Lift up to 4.5 kg (10 lb) frequently
  • Lots of walking or standing, or seated work using hand and foot controls

Medium work

  • Lift up to 22.7 kg (50 lb) occasionally
  • Lift up to 9.1 kg (20 lb) frequently
  • Lift up to 4.5 kg (10 lb) constantly

Heavy work

  • Lift up to 45.4 kg (100 lb) occasionally
  • Lift up to 22.7 kg (50 lb) frequently
  • Lift more than 9.1 kg (20 lb) constantly

Very heavy work

  • Lift more than 45.4 kg (100 lb) occasionally
  • Lift more than 22.7 kg (50 lb) frequently
  • Lift more than 9.1 kg (20 lb) constantly

How often the weight can be handled (frequency)

  • Occasional: Up to 33% of the day — this is the maximum safe load
  • Frequent: Up to 66% of the day — must be a lighter load than occasional
  • Constant: More than 66% of the day — must be a lighter load than frequent

Example: If the occasional limit is 20 kg, the frequent limit might be 10–12 kg, and the constant limit 5–7 kg.

How these standards are set

These definitions align with guidance from the National Institute for Occupational Safety and Health (NIOSH).They are used in the Canadian National Occupational Classification (NOC) and the U.S. Dictionary of Occupational Titles (DOT).