E928 - Benzole peroxide

At a glance

• What it is: An oxidizing and bleaching agent, better known as benzoyl peroxide.
• Where it’s used: Primarily in “bleached” wheat flour; also for decolorizing whey used in some cheeses (where allowed).
• Why it’s used: To whiten flour, even out natural color, and help achieve consistent appearance in baked goods.
• Safety: Permitted in the U.S. for specific uses under good manufacturing practice; evaluated by international bodies for its intended uses.¹²
• Also called: E928, benzoyl peroxide.

Why is Benzole peroxide added to food?

Processors add benzole (benzoyl) peroxide to oxidize natural pigments in flour—mainly carotenoids—so the flour appears whiter and more uniform from batch to batch.¹² It can also be used to decolorize whey destined for certain cheeses, helping standardize color without affecting flavor when used as specified.¹

What foods contain Benzole peroxide?

You’re most likely to encounter it in products made with “bleached” wheat flour, such as some all-purpose or cake flours and the baked goods made from them. In the U.S., flour that has been treated with a bleaching agent must be labeled as “bleached.”³ It may also be used in whey or dairy ingredients intended for specific cheeses where permitted.¹

What can replace Benzole peroxide?

Food makers can reach similar goals with other tools, depending on the product:

• Alternative bleaching agents: chlorine, chlorine dioxide (where allowed for specific flours).
• Dough strengtheners and oxidizers that affect texture more than color: ascorbic acid, calcium peroxide.
• Dough conditioners: azodicarbonamide (regulated by country).
• Enzyme solutions to improve handling: alpha-amylase, lipase.

How is Benzole peroxide made?

Industrial benzoyl peroxide is typically produced by reacting benzoyl chloride with hydrogen peroxide in an alkaline medium, then purified and formulated for safe handling.⁴ Food-grade material must meet identity and purity specifications before use in processing.¹

Is Benzole peroxide safe to eat?

In the United States, benzoyl peroxide is affirmed as Generally Recognized as Safe (GRAS) when used as a bleaching agent in accordance with current good manufacturing practice for specific foods such as wheat flour and whey.¹ International evaluations have also reviewed its use in food processing, noting that it functions by oxidation and decomposes during treatment, which limits consumer exposure to the parent compound under intended uses.²

Does Benzole peroxide have any benefits?

Its benefits are technological rather than nutritional:

• Produces a whiter, more uniform flour color for predictable product appearance.
• Helps standardize color in certain dairy ingredients used for cheese. These effects can simplify manufacturing and quality control, especially for products that depend on a pale crumb or consistent visual appeal.¹²

Who should avoid Benzole peroxide?

• If you prefer unbleached flour for culinary, labeling, or personal reasons, choose products labeled “unbleached.”
• People advised by a clinician to limit benzoates (compounds related to benzoic acid) may wish to consult their provider, since benzoyl peroxide’s reaction can form small amounts of benzoic acid; however, final levels are low under approved uses.²¹

Myths & facts

• Myth: It’s the same strong acne medication being eaten straight.
  Fact: Food-grade benzoyl peroxide is used in tiny amounts as a processing aid; it breaks down as it bleaches and is regulated for specific uses.¹²
• Myth: “Bleached” flour always lists benzoyl peroxide on the label.
  Fact: U.S. rules require the word “bleached” when a bleaching agent is used in flour; the specific bleaching agent may not always be named on retail labels.³

Benzole peroxide in branded foods

• In the U.S., many “bleached” all-purpose and cake flours may have been treated with a permitted bleaching agent such as benzoyl peroxide. Look for “bleached” in the flour’s name to identify this processing step.³
• Cheese and dairy labels may not call out benzoyl peroxide specifically; its use applies to certain ingredients (like whey) at the processing stage, within the limits set by regulation.¹

References

Footnotes

1. Benzoyl peroxide — 21 CFR 184.1157 (eCFR). https://www.ecfr.gov/current/title-21/section-184.1157 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰

2. Benzoyl peroxide (WHO Food Additives Series 5) — World Health Organization/FAO JECFA. https://inchem.org/documents/jecfa/jecmono/v05je19.htm ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

3. Enriched flour — 21 CFR 137.105 (eCFR). https://www.ecfr.gov/current/title-21/section-137.105 ↩ ↩² ↩³

4. Benzoyl peroxide — PubChem, National Institutes of Health. https://pubchem.ncbi.nlm.nih.gov/compound/6623 ↩