Hierarchy of volatile organic compound exposure measurement
| Exposure coding | Strength of the methodology |
| 1 Repeated personal exposure sampling with each sample >24 h | Optimal |
| 2 Repeated personal exposure sampling with each sample <24 h | Acceptable |
| 3 Single personal exposure sampling >24 h | Acceptable |
| 4 Single personal exposure sampling <24 h | Poor |
| 5 Repeated area/static exposure sampling from several household locations | Poor |
| 6 Single area/static exposure sampling from several household locations | Poor |
| 7 Repeated area/static exposure sampling from one household location | Poor |
| 8 Single area/static exposure sampling from one household location | Poor |