| carbon monoxide → IsA → colorless, odorless gas | 0.50 | |
| radon → IsA → colorless, odorless gas | 0.48 | |
| methane → IsA → colorless, odorless gas | 0.45 | |
| oxygen → IsA → colorless, odorless gas | 0.44 | |
| carbon dioxide → IsA → colorless, odorless gas | 0.43 | |
| ethane → IsA → colorless, odorless gas | 0.33 |