You will have used some dilute laboratory acids - such as hydrochloric acid, sulphuric acid and nitric acid - at school. Their bottles are labelled with the warning symbol for 'irritant'. This means that if any of them makes contact with your skin, it will become red or blistered. You must wash off any spills with plenty of water, otherwise your skin will soon feel as if it is burning.
'Irritant' hazard symbol
You are unlikely to have used concentrated acids but your teacher might have shown you some experiments with them. This is because concentrated acids are corrosive. They can attack metals and destroy skin if spilled.
'Corrosive' hazard symbol
Acids in the home
Although laboratory acids are far too dangerous to taste, and you must wear eye protection when using them, you will have swallowed some dilute weak acids. Acids have a sour taste. Think of vinegar, which contains ethanoic acid, and lemons, which contain citric acid. These are safe to use in food, but they can still hurt you if they get into a cut or into your eyes.
This diagram shows some of the acids found in the home
