2010, the International Programme on Chemical Safety (IPCS) concluded that commercially produced caramel color has the same toxicological properties as caramel produced by cooking or heating sucrose, except for those prepared using ammonium (Class III and IV). The IPCS has concluded that caramel color does not exhibit carcinogenicity or mutagenicity, based on its studies. Additional long-term studies support a conclusion that caramel colors are not carcinogenic. While the US FDA, Canadian Health Products and Food Branch and European Food Safety Authority (EFSA) have found caramel color safe for use in food and beverages, California has listed 4-Methylimidazole (4-MeI), a compound formed in the manufacture of Class III and IV caramel colors, in the state's Proposition 65, thus legally including it in the category of chemicals "known to the state to cause cancer or reproductive toxicity". According to the Food Chemicals Codex, 4-MeI in caramel color is allowed up to 250 ppm on a color-adjusted basis, which means 250 ppm maximum for every 0.100 color absorbance of a 0.10% solution at 610 nm. The exposure to 4-MeI at levels present in Class III and IV caramel colors are not expected to be of concern for two reasons. Firstly, 4-MeI does not appear to be genotoxic or metabolized to a reactive metabolite. Secondly, carcinogenic doses of 4-MeI exceed estimates of exposure from the consumption of caramel coloring by several thousand-fold. Food allergies Caramel coloring may be derived from a variety of source products that are themselves common allergens, namely starch hydrolysates (from wheat), malt syrup (in general derived from barley), or lactose (from milk). As such, persons with known sensitivities or allergies to food products are advised to avoid foods including generic caramel coloring or first determine the source for the caramel coloring before consuming the food. Caramel color produced from corn or cane-based materials would be unlikely to contain gluten due to the lack of gliadin in the carbohydrates. North American and European manufacturers mostly use glucose derived from corn or wheat to produce caramel color, which is highly processed and is generally considered gluten-free. References Sources Joint FAO/WHO Expert Committee on Food Additives (JECFA) specification for Caramel Colours U.S. Food and Drug Administration definition of Caramel, Code of Federal Regulations 21 CFR 73.85 European Commission Directive 95/45/EC (26 July 1995) on food color purity International Programme on Chemical Safety INCHEM Database Food colorings E-number additives