Table 1 Association for Work Design, Business Organization and Business Development (REFA) classification of work intensity

0

Working without carrying loads (e.g., desk work, office work)

1

Handling light work pieces, walking or standing around for long periods

2

Carrying loads of 20–30 lbs (10–15 kg), climbing stairs or ladders without load

3

Carrying loads of 40–60 lbs (20–30 kg), climbing stairs or ladders with moderate load, working in a tense posture

4

Carrying loads of more than 110 lbs (50 kg), climbing with heavy loads, hard work