What kind of acid is good and what kind is bad?

Answer 1

There's no definitive answer to that. It depends on your definition of good and bad.

However, there are strong acids and weak acids. The strong acids can be considered much more dangerous, and therefore "bad". The three worst acids by danger factor would be ...

• Hydroflouric acid
• Sulphuric acid
• Hydrochloric acid

Weak, less dangerous acids include acetic acid (used in vinegar) and citric acid (found in Oranges).

Of course, this all depends on how concentrated the acids are. For example, if you make an almost pure acetic acid solution, it's actually quite dangerous. And if you make a very very weak hydrochloric acid you could probably shower in it without too much of a problem. Luckily it's very difficult or expensive to make concentrated solutions of some of the strong acids, ie. you'd rarely find hydrochloric acid over 30%.

As a sidenote, please never underestimate how dangerous acids can be. My legs have massive third degree burn scars because I was half covered in 98% sulphuric acid (not a lie). If it had been hydroflouric acid I'd probably be dead.

Answer 2

Good acids, like hyaluronic acid and salicylic acid, can have benefits for the skin by providing hydration or helping to treat acne. Bad acids, like sulfuric acid or hydrochloric acid, are corrosive and can cause damage to the skin and other tissues if not handled properly.