| White quartz frequently coats the fluorite crystals and can be removed with hydrofluoric acid. |
| The cleaning materials have to be free of hydrochloric acid and hydrofluoric acid and must not be abrasive. |
| Light olefins from the fluid catalytic cracker are processed in either hydrofluoric or sulfuric acid units. |
| However, the cleaning materials must be free of hydrochloric or hydrofluoric acid and should not scratch the surface. |
| Chip production involves some pretty noxious substances, such as the decidedly nasty hydrofluoric acid used to etch the silicon wafers. |
| Toxic gases may be emitted, and poisoning from carbon monoxide, hydrofluoric acid, and sulphur dioxide can occur. |
