E150c

Ammonia Caramel

Last reviewed: 8 May 2026

The middle-class caramel — made with ammonia, no sulphites, carries trace 4-MEI

Caramel colour is not one ingredient — it is four. The E150 family covers four production classes, each made by heating sugar but with different reactants. E150a uses sugar alone. E150b adds sulphites. E150d uses both ammonia and sulphites. E150c — this page — uses ammonia but no sulphites. It sits in the middle of the family. The ammonia step produces a trace by-product called 4-methylimidazole (4-MEI), which is the compound regulators have looked at most closely. E150c carries less 4-MEI than E150d but more than E150a or E150b. On a UK label it can read "E150c", "Caramel Colour Class III" or "Ammonia Caramel". This page covers what it is, where it appears in UK products, how it differs from its three siblings, and the regulatory facts a label-reader actually needs.

Where E150c sits in the caramel family

The four classes are defined by what the sugar is heated with:

• E150a — Plain Caramel (Class I). Sugar only. No ammonia, no sulphites. No 4-MEI. The simplest of the four.
• E150b — Caustic Sulphite Caramel (Class II). Sulphites only, no ammonia. No 4-MEI. Sulphite-sensitive asthmatics may react.
• E150c — Ammonia Caramel (Class III). Ammonia, no sulphites. Carries trace 4-MEI from the ammonia step. Used in some beers, gravies, processed meats and biscuits.
• E150d — Sulphite Ammonia Caramel (Class IV). Both ammonia and sulphites. The highest 4-MEI burden of the four. The caramel used in major colas.

The classes are not interchangeable on a label. Each has its own E-number, its own production spec, and its own regulatory limits on residual compounds.

What E150c actually is

E150c is made by heating a sugar source — typically sucrose, glucose syrup or invert sugar — with ammonia or an ammonium compound under controlled temperature and pressure. The reaction produces a dark, water-soluble brown liquid or powder that disperses evenly through food.

The ammonia is volatilised off during processing. The finished colour does not contain free ammonia; it is the by-product chemistry that persists, not the reactant. The defining trace compound is 4-methylimidazole (4-MEI), which forms in measurable but small amounts whenever ammonia and reducing sugars react under heat.

E150c gives a richer, redder brown than E150a and is more colour-stable in acidic or alcoholic products. It is also cheaper per unit colouring strength than E150a, which is one of the main reasons manufacturers reach for it.

The 4-MEI question

4-methylimidazole is a small organic molecule that forms as a by-product when ammonia reacts with sugars at high temperature. It is not added; it is produced incidentally during the manufacture of E150c (and E150d). E150a and E150b do not produce it because they do not use ammonia.

The regulatory facts:

• EFSA 2011 re-evaluation set a maximum 4-MEI specification for Class III caramel of 250 mg/kg. Manufacturers must produce E150c that stays under this limit.
• EFSA 2011 individual ADI for E150c: 100 mg/kg of body weight per day. This is tighter than the group ADI of 300 mg/kg bw/day that covers all four classes combined — E150c is held to a stricter individual limit specifically because of 4-MEI.
• California Proposition 65 lists 4-MEI as a carcinogen. The state requires a cancer warning on products contributing more than 29 µg of 4-MEI per day to a person's exposure. E150c contributes to this exposure where it is used.
• FDA classifies all four caramel classes under "Generally Recognized as Safe" (GRAS) status. There is no separate FDA action level on E150c specifically.

Those are the numbers. We have stated them as published; we are not telling readers whether to consume E150c or not. The Prop 65 threshold and the EFSA ADI are different kinds of measurement — Prop 65 is a per-day exposure trigger for a warning label in California, set conservatively against animal carcinogenicity data; EFSA's ADI is a population-level intake reference, derived from the no-observed-adverse-effect level with a hundredfold safety factor. They are not directly comparable, and neither is a verdict on a given food.

Where you'll see E150c on UK labels

E150c shows up across a number of categories on UK shelves, though not the ones most people associate with caramel colour:

• Some beers, particularly darker styles. E150a is more common in stouts and traditional ales; E150c appears in some lagers and brown beers where colour stability matters.
• Gravy mixes and instant gravies — Bisto and similar products often list a caramel colour for the brown shade. Check the back of the pack for the specific class letter.
• Processed meats — some cooked hams, sausages and pâtés use E150c for colour stabilisation.
• Biscuits and bakery products, especially darker varieties such as ginger biscuits, malt loaves and some rye-style breads.
• Sauces and dressings — brown sauces, some marinades, malt-vinegar-based dressings.

Where E150c does not typically appear: major cola drinks. Coca-Cola and Pepsi globally, and their UK formulations, use E150d, not E150c. If a label says "Caramel Colour" with no class letter on a cola, that is a labelling issue (see the label-reading section below), not evidence that it is E150c.

E150c vs E150d — the key disambiguation

This is the comparison most readers come looking for, because the two ammonia-class caramels share the 4-MEI question but differ in important ways:

• Both use ammonia. Both therefore carry trace 4-MEI. E150a and E150b do not.
• Only E150d uses sulphites. E150c is sulphite-free. For someone tracking sulphite intake (asthmatics, wine-sensitivity), this is the practical difference.
• 4-MEI levels are higher in E150d. The combination of ammonia and sulphites in Class IV produces more 4-MEI than ammonia alone in Class III. E150d is closer to the EFSA Class IV cap; E150c sits lower on the scale.
• Different end-uses. E150d dominates cola drinks because it is the most acid-stable and gives the deepest brown at low concentrations. E150c is preferred in beers, meats, gravies and bakery — applications where sulphite-free is a formulation requirement or where cola-grade depth is not needed.

If a UK product carries Class III, it is by definition sulphite-free as far as the caramel is concerned (other ingredients may still contain sulphites; check the full ingredient list).

Regulatory status

E150c was re-evaluated by the European Food Safety Authority in 2011 as part of EFSA's review of all four caramel colours. The outcome:

• Individual ADI for E150c: 100 mg/kg body weight per day.
• Group ADI for the four caramel classes combined: 300 mg/kg body weight per day.
• Specification limits on 4-MEI in Class III: 250 mg/kg of finished colour.
• Permitted as a colouring additive in the UK and EU under retained Regulation (EC) 1333/2008 and the Annexes that set out which food categories may use it.

In the United States, the FDA lists all four caramel classes under "Generally Recognized as Safe" (GRAS) status. There is no FDA-set ADI; the agency relies on long-standing use and on the colour additive regulations in 21 CFR 73.85.

UK and EU labelling rules require Class III caramel to be declared as "E150c", "Caramel Colour Class III" or "Ammonia Caramel". Since the 2010 EU labelling reforms, "caramel colour" alone — without a class letter — is non-compliant on packs sold in the UK or EU. You may still see it on imported US-labelled products.

How to read a UK label for caramel class

If you want to know which caramel a UK product contains, the ingredient list will tell you. Look for one of these forms:

• "E150c" — explicit class letter. This is Class III, the one this page covers.
• "Caramel Colour Class III" — same thing, written out.
• "Ammonia Caramel" — same thing again, using the technical name. Some manufacturers prefer this over the E-number.
• "Caramel Colour" with no letter — this is non-compliant for UK retail since 2010. On a UK-labelled product it usually points to a labelling oversight; on an imported US product (Amazon, world-food shops) it is typical because US rules do not require the class to be declared.

The four classes are different ingredients with different specifications. A "caramel colour" line that does not say which class it is leaves you guessing on sulphite content and 4-MEI burden alike.

Why manufacturers pick E150c over the others

The choice between caramel classes is mostly about cost, colour properties and regulatory headroom:

• Cheaper than E150a per unit colouring strength. Plain caramel needs more product to reach the same depth of brown. E150c is more concentrated, so the cost per finished litre or kilogram of food is lower.
• Richer, redder brown than Class I. Useful in beers and meats where E150a's straw-to-amber tone is not what the formulation calls for.
• More colour-stable in acidic products than E150b. Sulphite-only caramels can shift hue in low-pH conditions; ammonia caramels hold their colour better.
• Lower 4-MEI burden than E150d. For a manufacturer worried about California Prop 65 exposure or about consumer scrutiny on 4-MEI, E150c is the easier compliance path among the two ammonia classes.
• Sulphite-free. For products targeting sulphite-sensitive consumers, E150c removes the caramel as a sulphite source. (The rest of the recipe still has to be checked.)

None of those are reasons for or against eating it. They are the reasons it ends up in a particular product.

For consumers, the practical takeaway is the labelling. UK packs by law tell you which class of caramel is in the product. If a beer, a gravy mix, a brown sauce or a packet of darker biscuits lists "E150c" or "Caramel Colour Class III", you now know what that line refers to: an ammonia-process caramel, sulphite-free, with trace 4-MEI within EFSA's Class III specification. Whether that matters in your weekly diet is a question of how often these products feature and how their cumulative 4-MEI compares to the daily reference points published by EFSA and California. The numbers are above; the choice is yours.