| Characteristics | Effective | % |
| Age (years) | ||
| Under 30 years | 27 | 34.2 |
| 30 - 40 | 45 | 57 |
| Over 40 years | 7 | 8.9 |
| Sex | ||
| Female | 0 | 0 |
| Male | 79 | 100 |
| Work rhythm | ||
| Daytime | 2 | 2.5 |
| Shift work | 77 | 97.5 |
| Seniority at the post |
|
|
| Less than 10 years | 57 | 72.1 |
| 10 - 20 years | 15 | 19 |
| More than 20 years | 7 | 8.9 |
| Smoking |
|
|
| Yes | 3 | 4 |
| No | 76 | 96 |
| Position type |
|
|
| Operator | 39 | 49.4 |
| Technician | 40 | 50.6 |
| Total | 79 | 100 |