| Similarity | Rank | |
|---|---|---|
| sulphur | 0.850 | 6647 |
| dioxide | 0.848 | 4762 |
| nitrous | 0.847 | 29606 |
| tetrachloride | 0.845 | 38419 |
| phosgene | 0.838 | 98640 |
| carbon | 0.834 | 3195 |
| oxide | 0.829 | 7892 |
| benzene | 0.823 | 21692 |
| methane | 0.822 | 11786 |
| nitric | 0.818 | 22052 |
| hexafluoride | 0.817 | 78594 |
| hydrochloric | 0.804 | 22757 |
| phenol | 0.794 | 28644 |
| nitrogen | 0.790 | 6386 |
| &sub2; | 0.789 | 34174 |
| chlorine | 0.789 | 10537 |
| ethane | 0.783 | 70857 |
| nox | 0.778 | 28969 |
| hydrocarbon | 0.777 | 12320 |
| particulate | 0.776 | 25930 |
| trioxide | 0.774 | 83599 |
| halon | 0.772 | 27495 |
| sulphuric | 0.772 | 21898 |
| vocs | 0.770 | 67555 |
| ammonia | 0.769 | 10958 |