Basic Information
As it is a liquid between a wide range of temperatures (190 K to 290 K), is a polar solvent with hydrogen bonding, and supports acid-base chemistry, hydrogen fluoride has been considered as a possible biological solvent. It can safely dissolve many organic molecules such as proteins and sugars, though there may be issues with salts and other inorganic compounds. The boiling point is close to room temperature so any such life would be most comfortable at low temperatures close to a winter in Antarctica. It reacts with water to make hydrofluoric acid, which is highly toxic and corrosive to inorganic matter such as bone, glass and metal.
How might a world where life uses hydrogen fluoride as a solvent look? It is quite a rare substance in a cosmic sense, so these planets would be very uncommon. A world with a little water and hydrogen fluoride seas is likely to have hydrofluoric acid in the clouds. The weathering effect of these substances means that a lot of fluoride minerals will exist in the rocks. The reaction of the hydrogen fluoride with minerals during geological activity might destroy the oceans long before the sun becomes a red giant and boils them away, so the length of the natural habitable lifespan relies on volcanic eruptions and hot springs replenishing the supply.
It does not seem likely that life that uses hydrogen fluoride as a solvent would breathe fluorine, as it is a corrosive and dangerous gas that is very poor for respiration.
Sources
Game and Story Use
- If an alien species based on hydrogen fluoride brought a large supply to drink, they might just be able to survive in the coldest parts of the world.
- They would need a respirator if they don't breathe oxygen, though.
- And maximum air conditioning to avoid heatstroke during the summer.
- Meeting an alien species in Antarctica has a nice sense of neutrality to it, if it's open contact, and it is an isolated location that seems ideal for secret contact with aliens.
- Just watch out for Global Warming.