⚠️ Critical Finding: The European Food Safety Authority found that actual consumer exposure to E522 is “most probably near zero” because uses are limited to specific niche products that most people don’t consume. This is one of the most heavily restricted food additives available.

Why Do Food Companies Use E522?

When used, E522 serves specific preservation functions.

First, it’s a firming agent that preserves the firmness and crispness of fruits and vegetables during candying, crystallizing, and glazing processes. Without it, these delicate foods would become mushy during processing.

Second, it acts as a color retention agent, preserving the natural appearance and pigments of processed produce.

Third, it stabilizes formulations and prevents separation or disintegration during long-term storage.

However, due to declining use and availability of alternatives, E522 use is increasingly rare. Data from the Mintel Global New Products Database shows the number of products containing aluminum sulphates (including E522) has been steadily declining since 2014.

Is It Safe?

Regulatory authorities say E522 is safe at approved use levels—but with major caveats.

The FDA classifies it as “Generally Recognized As Safe” (GRAS) when used per good manufacturing practices. The EFSA’s comprehensive 2018 re-evaluation concluded that aluminum sulphates (E520-523) “are of no safety concern in the current authorised uses and use levels.”

However, this approval comes with exceptional restrictions:

– Uses authorized in ONLY TWO food categories (vs. many for typical additives)
– “Further restrictions in use” apply within those categories
– Real-world consumer exposure: “Most probably near zero”
– Industry no longer submitting use data to EFSA
– Product count in stores declining

The Aluminum Concern

The primary health concern with E522 is its aluminum content.

Alums have been controversial due to historical associations with Alzheimer’s disease and other neurodegenerative conditions. However, important distinctions apply:

– Aluminum from E522 has LOW bioavailability (limited absorption)
– EFSA found NO evidence of carcinogenicity or genotoxicity
– EFSA found NO adverse reproductive or developmental effects
– EFSA found NO adverse neurotoxicity at approved levels
– Actual human exposure is negligible

The aluminum compounds form large molecules that are poorly absorbed through the gastrointestinal tract. High protein binding in blood limits systemic distribution, and renal clearance is slow, but at minimal exposure levels, this poses no identified health risk.

EFSA’s 2018 Comprehensive Safety Re-evaluation

The EFSA’s thorough 2018 assessment is critical to understanding E522.

Key findings:

– Aluminum sulphates pose no safety concern at current use levels
– No genotoxicity (genetic damage)
– No carcinogenicity (cancer)
– No reproductive/developmental toxicity
– Mean exposure: 0.0-0.21 mg/kg body weight per day
– 95th percentile exposure (highest consumers): 0.0-0.88 mg/kg bw per day
– Actual exposure “most probably near zero”

Most critically, EFSA noted that these additives are “only authorised in specific products which consumption is not captured in the dietary surveys”—meaning they’re so niche that standard exposure assessments can’t even measure them.

Dramatically Declining Use

E522’s use has dropped significantly since 2014.

The Mintel Global New Products Database shows a steady decrease in products containing aluminum sulphates (E520-523) since February 2014 legislative changes. Additionally, EFSA noted that industry is no longer submitting use data, suggesting manufacturers have largely abandoned these additives.

This declining trend reflects manufacturers’ preferences for non-aluminum alternatives and regulatory pressure to minimize aluminum additives.

Comparison with Related Alums

E522 is one of four aluminum-containing additives:

– E520: Aluminum sodium sulfate
– E521: Sodium aluminum phosphate
– E522: Potassium aluminum sulfate (this product)
– E523: Ammonium aluminum sulfate

All four have similar safety profiles and are similarly restricted. Of these, E522 is one of the least commonly used.

Manufacturing and Chemistry

E522 is synthetically produced through chemical reaction.

Aluminum sulfate (derived from bauxite ore) is reacted with potassium compounds to create the double sulfate compound. The resulting product is predominantly produced in the dodecahydrate form—containing 12 water molecules as part of its crystal structure.

It’s entirely synthetic with no natural source.

Vegan, Vegetarian, and Allergen Status

E522 is suitable for:

– Vegan diets ✓
– Vegetarian diets ✓
– Gluten-free diets ✓

Potassium aluminum sulfate is a chemical compound with no animal products or byproducts involved in its production.

The Bottom Line

E522 (potassium aluminum sulfate) is an aluminum-containing food additive used as a firming and color-retention agent in extremely limited niche products.

Regulatory authorities approve it as safe at approved use levels, with EFSA specifically finding “no safety concern in current authorised uses and use levels.”

However, uses are so severely restricted that actual human exposure is negligible—EFSA estimates real exposure as “most probably near zero.”

Product availability in stores is declining: the Mintel database shows fewer products containing this additive over time.

Most people will never consume E522, making theoretical safety debates largely academic.

As always, food labels must declare E522 when used—but finding products containing it requires considerable effort, as it’s one of the rarest food additives in modern commerce.