E527 - Ammonium hydroxide

At a glance

• What it is: A water solution of ammonia used as a pH control agent (to adjust acidity/alkalinity).
• Why it’s used: Helps manage acidity, supports food safety as a processing aid, and participates in making some caramel colors.
• Where it’s found: Meat processing, certain confectionery and caramel-colored foods and drinks, and occasional pH adjustment in manufacturing.
• Labeling: May appear as “ammonium hydroxide” or “E527.” In some cases (e.g., processing aids in meat), it may not appear on the label.
• Safety: Approved for use under strict conditions; concentrated solutions are caustic, but food uses are very small and controlled.

Why is Ammonium hydroxide added to food?

Food makers use ammonium hydroxide to control pH (how acidic or alkaline a mixture is). In the U.S., it is affirmed as Generally Recognized as Safe (GRAS) for this purpose when used in line with good manufacturing practice (GMP).¹

It is also allowed as a “safe and suitable” processing aid in meat and poultry production, where it helps control acidity and can reduce harmful bacteria during processing steps.² In addition, ammonium hydroxide can be used when making certain caramel colors produced by the “ammonia process,” which gives caramel a deeper hue and distinct flavor notes.³

What foods contain Ammonium hydroxide?

You’re most likely to encounter ammonium hydroxide indirectly:

• Meat and poultry products that have been treated with it during processing as a pH control agent or antimicrobial processing aid (it may not appear on the label in these cases).²
• Foods and drinks colored with “ammonia process” caramel colors, such as some types of ammonia caramel or sulphite ammonia caramel.³
• Occasional use for pH adjustment in manufacturing of confections or other foods, as allowed under GMP.¹

What can replace Ammonium hydroxide?

Depending on the recipe and regulation, common alternatives for pH control include:

• Alkaline options: sodium carbonates, potassium carbonates, sodium bicarbonate, sodium hydroxide, or potassium hydroxide.
• Acidic options (to move pH the other direction): citric acid or phosphoric acid.

The “best” swap depends on taste, texture, and labeling needs.

How is Ammonium hydroxide made?

Industrial ammonium hydroxide is simply made by dissolving ammonia gas in water to form a dilute solution. The resulting solution is alkaline and has the familiar ammonia smell.⁴

Is Ammonium hydroxide safe to eat?

In the U.S., ammonium hydroxide is affirmed as GRAS when used within good manufacturing practice, which limits both the purpose (pH control) and the amount added.¹ The USDA also lists it as safe and suitable for specific uses in meat and poultry processing, such as pH adjustment and antimicrobial interventions, under strict conditions.²

While concentrated ammonia solutions are corrosive and can irritate the eyes, skin, and lungs, the amounts used in food are small and are carefully controlled. Ammonia is also volatile, meaning it tends to dissipate readily as a gas, especially during processing.⁵

Does Ammonium hydroxide have any benefits?

• Food safety: In meat and poultry processing, it can help reduce harmful bacteria as part of approved antimicrobial or pH control steps.²
• Quality and consistency: It fine-tunes pH, which can influence color, texture, and flavor development.
• Color production: It participates in producing certain “ammonia process” caramel colors used for deeper color and characteristic flavor.³

Who should avoid Ammonium hydroxide?

The amounts used in food are very small and are not expected to pose special risks for most people. However, concentrated ammonium hydroxide (the household or industrial chemical) can release strong fumes that irritate the eyes and lungs; people with asthma or other respiratory conditions should avoid exposure to these fumes and use such products only as directed and never around food preparation areas.⁵ Keep concentrated solutions out of children’s reach.

Myths & facts

• Myth: “It’s the same as putting household cleaner in food.”
  Fact: Food-grade ammonium hydroxide is regulated and used in tiny, controlled amounts for specific purposes like pH control or processing steps.¹

• Myth: “It lingers in meat products.”
  Fact: When used as a processing aid under USDA rules, it’s applied under strict conditions, and ammonia is a volatile compound that tends to dissipate during processing.²⁵

• Myth: “It’s only a preservative.”
  Fact: Its primary role is pH control; it also participates in making certain caramel colors used for flavor and appearance.³

Ammonium hydroxide in branded foods

• How it appears: In the EU, it may be listed as “E527” or “ammonium hydroxide.” In the U.S., it may be listed by name when used as an ingredient; when used solely as a processing aid in meat and poultry, it may not appear on the label under USDA rules.²
• Where to look: Check ingredient lists on confectionery and specialty products, and be aware that some caramel-colored foods and beverages use caramel colors made with ammonium compounds.³
• Related labels: Leavening in baked goods is usually from ammonium salts like ammonium carbonates, not ammonium hydroxide itself.

References

Footnotes

1. 21 CFR 184.1139 — Ammonium hydroxide. U.S. Food and Drug Administration (eCFR). https://www.ecfr.gov/current/title-21/part-184/section-184.1139 ↩ ↩² ↩³ ↩⁴

2. FSIS Directive 7120.1: Safe and Suitable Ingredients Used in the Production of Meat, Poultry, and Egg Products. U.S. Department of Agriculture. https://www.fsis.usda.gov/policy/fsis-directives/7120.1 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

3. 21 CFR 73.85 — Caramel. U.S. Food and Drug Administration (eCFR). https://www.ecfr.gov/current/title-21/part-73/section-73.85 ↩ ↩² ↩³ ↩⁴ ↩⁵

4. Ammonium Hydroxide. PubChem, National Institutes of Health. https://pubchem.ncbi.nlm.nih.gov/compound/14923 ↩

5. Ammonia: ToxFAQs. Agency for Toxic Substances and Disease Registry (ATSDR/CDC). https://wwwn.cdc.gov/TSP/ToxFAQs/ToxFAQsDetails.aspx?faqid=11&toxid=2 ↩ ↩² ↩³