As with splashes in the eyes, prevention is better than cure. Handle corrosive (and other) chemicals carefully ro avoid spillages as far as possible.

Gloves are often a good idea but be careful that un-noticed splashes on the outside of the gloves don't get transferred to unprotected areas - by rubbing your eyes for instance.

Wash under gently running water for 5 minutes or until all traces of the chemical have disappeared. If the water is cold, it can become painful. Allowing the injured person to take their hands out of the water from time to time is perfectly reasonable.

If the spill is significant, you might need to get the victim to remove contaminated clothing. The problem is that it will keep the harmful substance in contact with the skin if not removed, causing further damage.

You can see that this could cause other difficulties though – you might need to get a colleague (or even another pupil of the same sex) to escort the victim somewhere nearby where they can take off anything contaminated.

If the chemical adheres to the skin, wash gently with soap – don’t rub hard as this might tear off any damaged skin or blisters.