| Subject | English | Spanish |
| environ. | non-volatile substance | sustancia permanente |
| environ. | non-volatile substance Substance that is not capable of changing from a solid or liquid form to a vapour | sustancia permanente |
| health. | volatile substance | sustancia volátil |
| environ. | volatile substance A substance capable of readily changing from a solid or liquid form to a vapour; having a high vapour pressure and a low boiling point | sustancia volátil |