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  5. 3-Monochloropropane-1,2-diol (MCPD) Esters and Glycidyl Esters
  1. Chemical Contaminants in Food

3-Monochloropropane-1,2-diol (MCPD) Esters and Glycidyl Esters

Process Contaminants in Food

3-monochloropropane-1,2-diol esters (3-MCPDE) and glycidyl esters (GE) are contaminants that can occur in edible oils, such as vegetable oils, and foods made from these oils. Both food manufacturers and consumers use edible oils as an ingredient in foods and for cooking. During industrial refining, 3-MCPDE and GE can form in edible oils when the oils are heated at very high temperatures to remove unwanted tastes, colors, or odors. The highest concentrations typically occur in refined palm oil and palm olein oil, but 3-MCPDE and GE also are found in other refined vegetable oils (such as safflower, coconut, sunflower, and soybean oils) and refined marine oils (such as fish oils).

During digestion, 3-MCPDE and GE break down to the organic chemicals 3-monochloropropane-1,2-diol (3-MCPD) and glycidol. In studies of rodents, 3-MCPD caused adverse effects on kidneys and male reproductive organs, and both 3-MCPD and glycidol caused cancer. To better understand the potential risks of 3-MCPDE and GE in foods for humans, the FDA has developed methods to measure these contaminants in foods, conducted surveys of edible oils and other foods containing edible oils, and researched the potential adverse health effects of 3-MPCDE and GE.

Refined vegetable oils are a major component of infant formula, because fats from added oils are important for infant nutrition. Since infants are a vulnerable population, FDA work has focused on measuring levels of 3-MCPDE and GE in infant formulas to ensure the safety of infant formula. The FDA has also engaged with industry to share information on the health effects of 3-MCPDE and GE and the availability of mitigation methods for refined edible oils and infant formula to help reduce the levels of these contaminants.

In addition, the Codex Alimentarius Commission, in which FDA participates, developed recommendations for industry on reducing 3-MCPDE and GE in refined oils and foods. As chair of a Codex working group, the U.S. helped to develop a code of practice that outlines agricultural, refining, post-refining, and processing measures that industry can use to reduce levels of 3-MCPDE and GE in refined oils and foods made from refined oils.

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