The U.S. on Wednesday banned the use of a synthetic food dye that gives some candies, cakes and certain oral medications a cherry-red color, following evidence that the dye causes cancer in laboratory rats.

(Reuters) -The U.S. Food and Drug Administration on Wednesday banned the use of Red No. 3, a synthetic food dye that gives some candies, cakes and oral medications a cherry-red color, following evidence that the dye causes cancer in laboratory rats.

FDA officials have telegraphed the decision for months. While the agency has long said that it did not think evidence of Red 3 causing cancer applied to humans, officials said their hand was forced by a law requiring the agency to pull additives that are cancerous in animals.

The FDA said it will ban Red Dye No. 3, a substance that colors many products but has been shown in studies to cause cancer in rats. Food manufactures will have two years to remove the substance from their products.

Red No. 3, chemically known as erythrosine, was first introduced into foods in 1907. Companies subsequently added it to thousands of products to boost their colors over the decades, often in snacks like ice cream and candy marketed directly to children.

The FDA banned the use of red dye No. 3 in foods and medicines sold in the U.S. because it has been shown to cause cancer in rats. The action highlights the limits of a federal law known as the Delaney clause.