| F/E | Frequency | Exposition |
| 5 | One or more times per day. Happens “all the time”. | work time >90% |
| 4 | One or more times a week. Everyone remember this kind of event/situation. | 50%< work time ≤90% |
| 3 | One or more times per month. Some people remember this type of event/situation. | 25%< work time ≤50% |
| 2 | One or more times per year. Someone remembers this type of event/situation. | 5%< work time ≤25% |
| 1 | Less than once a year. No memory of this type of event/situation. | work time ≤5% |