Prime: Can you tell energy and hydration drinks apart?
Fears have been expressed caffeine warnings are not being printed clearly on Prime Energy drinks.
They come after Milton Primary School, in Newport, sent a text to parents about it after a pupil fell ill outside school hours.
The BBC asked people in Cardiff whether they would know the difference between Prime Energy and Prime Hydration.
One woman asked if one of the drinks was fake. Other passers-by had no idea what the difference was.
But some had the right answer.
"I can see very clearly that one says 'energy drink', that one says 'hydration'," one woman said.