Major suspected aetiologies in cases reported by the Observatoire National des Asthmes Professionnels (ONAP) in 1997
| Substances | Absolute number | Percentage |
| Flour | 130 | 23.3 |
| Isocyanates | 93 | 16.6 |
| Latex | 42 | 7.5 |
| Aldehydes | 31 | 5.5 |
| Persulphates | 23 | 4.1 |
| Wood dust | 22 | 3.9 |
| Enzymes | 19 | 3.4 |
| Dust mite | 18 | 3.2 |
| Glues and resins | 15 | 2.7 |
| Mammals | 13 | 2.3 |
| Grain | 10 | 1.8 |
| Amines | 9 | 1.6 |
| Colophony | 8 | 1.4 |
| Acids | 7 | 1.3 |