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  1. Chemical Contaminants & Pesticides

Process Contaminants in Food

Food processing happens anytime you take fresh food and change it into a cooked dish or food product. Whether you are cooking food at home or a manufacturer is preparing food in a facility, food processing can help ensure food safety and quality. It is also a way to make food taste better and last longer.

Process contaminants are undesired chemical by-products that can form during food processing, especially when heating, drying, or fermenting foods. They can form during home cooking and in manufacturing facilities, and in some cases, low levels may be unavoidable. Not all are harmful, but some process contaminants have been linked to potential health effects.

In order to protect public health, the FDA researches how process contaminants form, develops measurement methods, and surveys levels of process contaminants in foods. When we determine that the levels of contaminants in a food are unsafe, we take measures to reduce their presence in the food supply. We also work with the food industry and international organizations to help reduce process contaminants in foods as well as provide guidance and information to industry and consumers.

Examples of Process Contaminants

Process contaminants can be found in plant-based and animal-based foods. Examples of process contaminants include acrylamide, ethyl carbamate, furan, 3-monochloropropane-1,2-diol esters (3-MCPDE), glycidyl esters (GE), nitrosamines, heterocyclic amines, 4-methylimidazole (4-MEI), and polycyclic aromatic hydrocarbons (PAHs).

We engage in research on process contaminants in the food supply. Studies show that high doses of these contaminants or their breakdown products can cause cancer in laboratory animals, but the levels used in these studies were much higher than those typically found in human food. For additional information on each of these process contaminants, please visit the individual webpage links.

  • Acrylamide is a substance that can form in plant-based foods, including potato and cereal-grain-based foods, during high-temperature cooking such as frying, roasting, and baking. The FDA measures acrylamide in foods and developed Guidance for Industry on Acrylamide in Foods that outlines strategies for growers, manufacturers, and food service operators to reduce acrylamide in the food supply. For consumers, we have resources for reducing acrylamide exposure in food prepared at home.
  • Ethyl carbamate can form during fermentation of beverages and other foods. We have developed analytical methods that industry and we can use to measure ethyl carbamate in foods, evaluated levels in foods and beverages, and shared resources from academia and industry on ways to control ethyl carbamate in wine.
  • Furan can form in some foods during heating, such as cooking, jarring, and canning. We developed a method to measure furan, surveyed furan levels in food, and published toxicology studies on furan.
  • 4-Methylimidazole (4-MEI) can form at low levels in some foods during cooking, including roasting coffee beans, roasting or grilling meats, and during manufacture of certain types of caramel coloring used in foods. As part of an ongoing review of color additive safety, we published an assessment in 2018 of consumer exposure to 4-MEI from certain caramel colors as well as from heat-treated foods.
  • 3-Monochloropropane-1,2-diol (3-MCPDE) and Glycidyl Esters (GE) can form in edible oils, such as vegetable oils, during industrial refining when these oils are heated at high temperatures to remove unwanted tastes, colors, and odors. The FDA has developed methods to measure 3-MCPDE and GE in foods, conducted surveys of edible oils and other foods containing edible oils (such as infant formula), and researched the potential adverse health effects of 3-MCPDE and GE. We also continue to engage with the food industry to exchange information on mitigation methods and helped develop an international code of practice outlining how industry can reduce levels of 3-MCPDE and GE in refined oils and foods made from refined oils.

International Scientific Activities

The FDA participates in the international standard-setting body Codex Alimentarius Commission (Codex). The purpose of Codex is to protect the health of consumers and promote fair trade practices by adopting scientifically based standards, guidelines, and codes of practice across all areas of food safety and quality. Codex has developed codes of practice for reducing acrylamide, 3-MCPDE/GE, PAHs, and other process contaminants in foods.

From Other Government Agencies

Other federal and international government agencies also provide useful information about process contaminants. Here are some good places to start:

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