As the demand for clean-label ingredients and transparency in food manufacturing continues to rise, so too does curiosity—and concern—around food processing byproducts. One such compound that occasionally surfaces in discussions about caramel colour is 4-MEI, or 4-Methylimidazole. At Posh, we believe informed customers make confident decisions. Here’s what you need to know.

What is 4-MEI?

4-Methylimidazole (4-MEI) is a naturally occurring byproduct that can form when sugars and certain ammonium compounds are heated together at high temperatures—a process used in the production of Class III and Class IV caramel colours.

It is not an added ingredient, nor is it unique to caramel colour; 4-MEI can also be found in small amounts in coffee, roasted foods, baked goods, and even some soft drinks.

How Does It Form?

4-MEI forms as a result of the Maillard reaction, a common browning and flavor-developing process in cooked foods. In the case of caramel colours, it occurs when:

• Sugars are subjected to heating, and
• Ammonium-based reactants are present (as used in Class III and Class IV caramels)

While the reaction is carefully controlled in commercial caramel production, small amounts of 4-MEI may still be formed depending on the formulation and cooking parameters.

What Do the Regulations Say?

Different regions have different thresholds and perspectives on 4-MEI. For example:

• California’s Proposition 65 includes 4-MEI on its list of substances subject to labeling above certain limits for food and beverage products.
• International food safety bodies like the EFSA (European Food Safety Authority) and JECFA (Joint FAO/WHO Expert Committee on Food Additives) have evaluated 4-MEI and consider the trace levels found in caramel colours to be safe at typical consumption levels.

That said, some countries and markets have not yet implemented specific 4-MEI limits, leaving room for manufacturers to take a proactive approach.

Can Caramel Colours Be Made with Lower 4-MEI?

Yes, they can—though doing so requires advanced technology. While maintaining flavour, appearance, and functional performance, manufacturers can significantly reduce 4-MEI formation in Class III and Class IV caramel colors.

At Posh, this is a field of ongoing development, and we have the capability to produce extremely low 4-MEI caramel colors for customers who are preparing their products—and their reputations—for the future.

The Bottom Line

4-MEI is a naturally occurring byproduct—not an additive—in some types of caramel color and many processed foods. While most global authorities currently regard trace levels as safe, regulations are evolving, and so are consumer expectations.

For brands looking to stay ahead of future labeling requirements or clean-label trends, lowering 4-MEI content is a proactive step worth considering.

At Posh, we understand the science—and we’re already helping customers explore low-4-MEI caramel solutions that align with both performance needs and long-term transparency goals.