E150d – Sulfite Ammonia Caramel (Class IV)

Safety grading ORANGE – SOME CONCERNS

E150d, or Sulfite Ammonia Caramel (Class IV), is the darkest and most commonly used caramel in colas and many dark sauces. We grade it ORANGE – SOME CONCERNS. Its manufacture uses both ammonium and sulfite compounds, creating a strongly coloured, anionic caramel with excellent stability in acidic beverages. The combination of reagents can generate trace 4‑methylimidazole and retain small amounts of sulfite. Regulatory reviews conclude that exposures from foods are typically below levels of concern, but the by‑product profile warrants moderation for heavy consumers.

Producers have implemented process controls and reformulation strategies to keep impurity levels low while preserving the expected colour and flavour profile of flagship beverages. Consumers who wish to minimize exposure can moderate consumption of dark soft drinks, choose brands that disclose lower 4‑methylimidazole targets, or opt for products coloured with Class I caramel instead.

Should You Avoid E150d?

Total avoidance is unnecessary for most people. Moderation is sufficient, especially for heavy consumers of dark colas or sauces. Individuals with sulfite sensitivity may prefer alternatives that use E150a or no added colours.

Common Uses

Cola and other dark soft drinks where strong brown colour and acid stability are required.
Barbecue sauces, soy sauce, gravies, and savory concentrates.
Dark beers and malt beverages.

Common names / Synonyms

Sulfite ammonia caramel
Class IV caramel
Caramel colour E150d
INS 150d

What is it?

E150d is produced by heating sugars with both ammonium and sulfite compounds under controlled conditions of temperature, time, and pH. The resulting caramel carries a negative charge, which helps it remain dispersed in acidic matrices such as colas. Manufacturers closely manage the process to minimize formation of heterocyclic by‑products while achieving the deep hue expected by consumers. Ongoing surveillance and specification testing verify that identity and purity criteria are met.

Where it’s allowed (EU vs US)

E150d is permitted in the European Union as a food colour with conditions of use. In the United States it is recognized as GRAS when produced to specification and used according to good manufacturing practice. Some jurisdictions have issued guidance encouraging continued reduction of 4‑methylimidazole levels in soft drinks.

Under the conditions of these 2-year feed studies, there
was no evidence of carcinogenic activity* of 4-methylimidazole in male F344/N rats exposed to 625,
1,250, or 2,500 ppm. There was equivocal evidence of carcinogenic activity of 4-methylimidazole in female
F344/N rats based on increased incidences of mononuclear cell leukemia.

There was clear evidence of carcinogenic activity of 4-methylimidazole in male and female B6C3F1 mice based on increased incidences of alveolar/bronchiolar neoplasms.

Exposure to 4-methylimidazole resulted in nonneoplastic lesions in the liver of male and female rats and the
lung of female mice and in clinical findings of neurotoxicity in female rats.

2007-caramel-coloring-NTP-TECHNICAL-REPORT-TOXICOLOGY-AND-CARCINOGENESIS-STUDIES-OF-4-METHYLIMIDAZOLE Download