3-MCPD and Glycidyl Esters in Edible Oils: A Guide for Buyers

If you buy refined oils for products sold in the European Union, or for infant foods anywhere, sooner or later you will be asked about 3-MCPD and glycidyl esters. They are process contaminants: substances that form during processing rather than coming from the raw material. This guide explains what they are, how they form, the limits that apply and what to ask your supplier.

What they are

• 3-MCPD (3-monochloropropane-1,2-diol) occurs in refined oils mainly bound to fatty acids, as 3-MCPD esters. A related compound, 2-MCPD, is often measured with it.
• Glycidyl esters are fatty acid esters of glycidol. In the body they are thought to release glycidol, so results and limits are expressed as glycidol.

How they form

Both form mainly when vegetable oils are heated to high temperatures during refining, especially in deodorization, the step that removes odors and flavors. According to Germany’s Federal Institute for Risk Assessment (BfR), they arise mainly during the heat treatment used to purify and refine vegetable fats and oils, and refined fats such as palm oil may contain them. Free 3-MCPD can also form when foods containing fat and salt are heated to high temperatures during manufacturing.

Unrefined oils, such as cold-pressed and virgin oils, are not deodorized at high temperature, so they generally contain little or none. Our guide to refined vs cold-pressed oil explains the processing differences.

What food safety authorities say

• 3-MCPD: the European Food Safety Authority (EFSA) set a tolerable daily intake of 2 micrograms per kilogram of body weight per day, based on effects on the kidneys. Most adults stay below this, but infants fed only formula, and some young children, may exceed it.
• Glycidol: glycidol has genotoxic and carcinogenic properties, so no safe intake level can be set. Authorities assess the risk using a margin of exposure, and the aim is to keep levels as low as reasonably achievable.

These assessments are why limits are strictest for oils used in infant and young children’s foods.

EU maximum levels

The EU set maximum levels for both contaminants, applying from January 1, 2021, under Commission Regulation (EU) 2020/1322. The limits now form part of the EU’s main contaminants regulation, (EU) 2023/915.

Product	3-MCPD and its esters (as 3-MCPD)	Glycidyl esters (as glycidol)
Coconut, maize (corn), rapeseed (canola), sunflower, soybean, palm kernel and olive oils (refined and virgin blends)	1,250 µg/kg	1,000 µg/kg
Other vegetable oils, including palm oil and olive pomace oil, and fish and marine oils	2,500 µg/kg
Oils for baby food and processed cereal-based food for infants and young children	750 µg/kg	500 µg/kg

For mixtures of oils from both groups, the limit is calculated from the proportions of each oil, with 2,500 µg/kg applying when the composition is unknown. Separate, lower limits apply to infant formula itself. Other countries may set their own limits or follow Codex guidance, so check the rules in each market you sell in.

How refiners keep levels low

Refiners reduce these contaminants by controlling both the raw material and the process. Common approaches include:

• Better raw material, such as processing palm fruit quickly and reducing chlorine-containing compounds before refining.
• Washing crude oil to remove chloride precursors.
• Gentler deodorization, using lower temperatures, shorter times or two-stage processes.
• Treatments after refining to remove glycidyl esters that have formed.

What to ask your supplier

• Tell them your market and use at the quotation stage: oil for EU retail, for food manufacturing, or for infant foods each has a different limit.
• Ask for results for 3-MCPD (and 2-MCPD if needed) and glycidyl esters, by a recognized method, on the Certificate of Analysis or in a test report.
• Include the limits in your specification. Our guide to writing a purchase specification shows where they fit.
• Consider the oil choice. Palm-based oils fall under the higher 2,500 µg/kg limit, and refined palm products need the most attention; if your product is for infants, discuss suitable oils with your supplier.

Our approach

Every lot we supply is tested before release and comes with a Certificate of Analysis. If you are buying for an EU market or for infant and young children’s foods, tell us in your quote request, and we will confirm the relevant results and limits for the oils you choose. See our guides to palm products and reading a Certificate of Analysis, or add your oils to your quote list.

Sources

• Commission Regulation (EU) 2020/1322 on maximum levels of 3-MCPD and glycidyl fatty acid esters
• German Federal Institute for Risk Assessment (BfR): Health risks of 3-MCPD, 2-MCPD and glycidyl fatty acid esters
• AGRINFO: Maximum levels for 3-MCPD and glycidol