E173

Aluminium

Moderate risk coloursynthetic

Metallic surface color; aluminium intake concern.

Tolerable weekly intake: 1 mg/kg body weight/week (EFSA)
Vegan: Yes
Vegetarian: Yes

What it is

E173 is elemental aluminium used purely for aesthetic purposes to give a shiny, metallic silver finish to the surface of foods. It is almost exclusively used in confectionery and cake decorating.

How it is used in food

Used for silver decoration.

Commonly found in

Silver dragées (the hard silver balls on cakes)
Metallic cake decorations and icing
Sugar-coated chocolates and pastries

Health and safety

Contributes to total dietary aluminium, which accumulates in the body.

Aluminium is neurotoxic and affects bone health if it accumulates in the body over time. Because of this, health authorities have established a strict Tolerable Weekly Intake (TWI), and the use of E173 is heavily legally restricted to prevent widespread dietary exposure.

Neurotoxicity and bone toxicity

general population · evidence: established

Excessive and prolonged exposure to aluminium leads to its accumulation in the body, which has been shown to cause neurotoxicity (damage to the nervous system) and impair bone formation.

Safety of aluminium from dietary intake

Dietary aluminium accumulation is a recognized concern.

Regulatory status

Region	Status	Notes
Australia & New Zealand FSANZ	Permitted	Permitted in specific categories with strict limits.
European Union EFSA / European Commission	Permitted	Authorised for food use under EU regulations (Annex II).
United States FDA (Food and Drug Administration)	Banned	Not an approved colour additive for food in the US. Metallic decorations containing it are sold only as non-edible cake decorations, labelled "for decorative purposes only". “Banned”

Identification on labels

E-number: E173
Colour index: 77000

Also printed asAluminum

How it is made

Elemental aluminium is milled into an extremely fine metallic powder or formulated into thin flakes.

Milling — Pure elemental aluminium is ground into microscopic particles or flakes to create a silver pigment.

Worth knowing

EFSA keeps it on a tight weekly limit.

Conclusion

E173 is entirely cosmetic. While occasional consumption on a decorative cake or pastry is unlikely to exceed the weekly safety thresholds, it is an unnecessary source of a known neurotoxin and is easily avoided.

References

Safety of aluminium from dietary intake — EFSA

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Entry last reviewed 2026-07-28.

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