| Compound | Concentration [Vol. %] |
| Methane (CH4) | 55 - 70 |
| Carbon dioxide (CO2) | 30 - 45 |
| Nitrogen (N2) | 0 - 5 |
| Water (vapour) | 1 - 5 |
| Siloxanes (CnH2n+1SiO) | 0 - 50 mg/m³ |
| Oxygen (O2) | <1 |
| Hydrogen sulfide (H2S) | 0 - 0.5 |