Aluminium Sulfate E520
stabilizer, carrier — Primarily synthetic.
Aluminium sulfate (Al2(SO4)3)
CAS: 10043-01-3
Factual Regulatory Reference
This database provides factual regulatory information compiled from official government sources. It does not constitute medical, nutritional, or safety advice. Regulatory status varies by country and is subject to change. Always refer to your local regulatory authority for the most current information.
What Is Aluminium Sulfate?
Aluminium sulfate functions as a firming agent used in pickled cucumbers and other pickled products to maintain crispness. It is also used as a leavening acid in some baking powders. EFSA raised concerns in 2008 about total dietary aluminum exposure from all sources (food naturally, food contact materials, additives), establishing a Tolerable Weekly Intake (TWI) of 1 mg/kg body weight. The EU has restricted aluminum-containing additives, including aluminum sulfate, to ensure total dietary aluminum exposure remains within safety limits.
? Did You Know?
Beyond food, Aluminium Sulfate is also used in cosmetics, medicine, industrial applications, household products. Its versatility makes it one of the most multi-purpose chemical compounds in everyday life.
Regulatory Analysis
Aluminium sulfate (E520) is one of several aluminium-containing food additives — alongside E173, E541, and E554 — whose authorization in the EU is conditional on EFSA's tolerable weekly intake (TWI) for dietary aluminium of 1 mg/kg body weight per week, established in 2008. EFSA's 2018 group re-evaluation of aluminium-containing food additives maintained this TWI and emphasized that certain consumer subgroups, particularly children who consume multiple aluminium-containing additive products, can approach or exceed it. Unlike food-grade metallic aluminium (E173) — authorized only as a surface decoration — aluminium sulfate contributes soluble aluminium that is more bioavailable. The FDA treats aluminium sulfate as GRAS under 21 CFR 184.1121 for specific uses in pickling. No jurisdiction has banned E520, but the EU has imposed strict maximum residue limits in permitted categories, reflecting a cumulative aluminium exposure management approach.
Detailed Regulatory Assessment
European Union (EFSA)
Permitted in limited food categories with maximum residue limits. Primarily candied and crystallized fruits.
Official EFSA LinkUnited States (FDA)
Limited to specific uses in food processing, particularly pickling.
Japan (MHLW)
Restricted use with maximum residue levels.
Acceptable Daily Intake (ADI)
International Standard (JECFA)
mg/kg body weight per day
European Standard (EFSA)
Natural Occurrence
This additive is not known to occur naturally in significant quantities.
Manufacturing
Produced by reacting aluminum hydroxide or bauxite ore with sulfuric acid. The solution is then crystallized to obtain various hydrated forms of aluminum sulfate.
Applications Beyond Food
Astringent in some antiperspirants and styptic pencils (though potassium alum is more common).
Vaccine adjuvants (though usually as aluminum hydroxide or phosphate).
Water treatment (flocculation), paper sizing, dyeing mordant, fireproofing textiles.
Pickling cucumbers (in some traditional recipes), water purification.