| Standard | Atmosphere is a good mix of breathable gases with few impurities. | |
| Tainted | Atmosphere is a tolerable mix of gases to breath. Air may contain visible levels of impurities. | |
| Exotic | Atmosphere is poisonous to people and animals but may host plant life. Environment suit required. | |
| Corrosive | Atmosphere is poisonous to all plant and animal life. Corrosive to all equipment. | |
| Insidious | Atmosphere is extremely poisonous to all plant and animal life. Extremely corrosive to all equipment. |