Sodium aluminium silicate

Sodium aluminium silicate is a synthetic aluminosilicate mineral used as an anti-caking agent in powdered and granular foods. It prevents moisture absorption and particle adhesion that cause ingredients to cake during storage. Applied in very small quantities, it is effective at maintaining free-flowing properties in table salt, dried egg powder, dehydrated soups, and similar products. Its absorption capacity and fine particle size allow it to distribute evenly through a powdered matrix.

JECFA reviewed sodium aluminium silicate in 2006 as part of its broader reassessment of aluminium-containing food additives and concluded that an ADI could not be allocated. This outcome reflected insufficient toxicological data to establish a safe numerical limit, combined with general regulatory concerns about total dietary aluminium exposure. The aluminium content of aluminosilicate compounds is bound within a mineral lattice, making it less bioavailable than ionic aluminium salts, but the conservative "not allocated" classification remains in force.

In the EU, E554 is permitted for use in specific food categories under controlled maximum levels, and its approval is qualified by considerations about aggregate aluminium intake from all food additives combined. Consumers who want to minimise aluminium in their diet may look for products using alternative anti-caking agents such as calcium carbonate or silicon dioxide. The concern is proportional to overall exposure rather than any single food item; occasional consumption of products containing E554 at permitted levels is unlikely to pose a risk to most adults. Regulatory review is ongoing as EFSA continues monitoring total aluminium intake across populations.