Potatoes will often go green when they're not stored properly and they're exposed to light. This is due to formation of chlorophyll (which is found in all green plants), however the green colour is a useful indicator that levels of certain toxins that are harmful to humans, known as glycoalkaloids, may be increased.

Can you eat potatoes with a green tinge?

Green potatoes should be taken seriously. Although the green color itself is not harmful, it may indicate the presence of a toxin called solanine. Peeling green potatoes can help reduce solanine levels, but once a potato has turned green, it's best to throw it away.

How much green on a potato is safe?

A recent study suggested that a 16-oz (450-gram) fully green potato is enough to make a small adult ill. Cooking does not destroy the solanine toxin, so the green parts of potatoes should be removed entirely.