Ponceau Red food colouring molecule. Molecular model of Ponceau Red, an organic compound used as a food colouring. Ponceau Red, also known as Ponceau 4R and E124, is very commonly used in the UK, but is banned in the USA, Norway and Finland as they believe it is carcinogenic. There are also concerns over this food colouring being linked to allergic reactions, hyperactivity and temper tantrums in children. Research has shown that behaviour problems increase with higher additive levels in food, so parents have been advised not to give children foods containing these additives. Atoms are colour-coded: hydrogen (gold), carbon (red), nitrogen (dark blue), sulphur (yellow) and oxygen (orange).