Dimethylpolysiloxane vs Sodium Aluminum Phosphate: which is worse?

What is Dimethylpolysiloxane?

Dimethylpolysiloxane (PDMS, polydimethylsiloxane) is a silicone-based polymer used as an antifoaming agent in food and beverages. It prevents the formation of foam during food manufacturing and cooking. It is the same base material used in silicone cookware, medical devices, and contact lenses.

What is Sodium Aluminum Phosphate?

Sodium aluminum phosphate (SALP) is a leavening acid and food additive used in baked goods, particularly self-rising flour and baking powder. It provides a slow, sustained leavening action during baking. SALP is also used as an emulsifying salt in processed cheese products.

Documented risks

Dimethylpolysiloxane: Dimethylpolysiloxane is generally considered non-toxic. It is not absorbed by the gut and passes through the digestive system unchanged. The FDA permits it at up to 10 ppm in cooking oils. EFSA's evaluation found no evidence of toxicity at permitted food use levels. There are no established cancer or reproductive toxicity concerns with PDMS at food use concentrations. The compound is the same base polymer used in many safe medical applications including contact lenses and breast implants (though the medical grade is different purity). The main environmental concern is PDMS persistence in the environment, as it is not readily biodegradable. Primary consumer concern is psychological rather than toxicological: the fact that it is used in both McDonald's frying oil and Silly Putty (which also contains PDMS) generates public attention, but the chemistries are actually different grades of the same polymer family.

Sodium Aluminum Phosphate: The primary health concern with SALP is aluminum exposure. Dietary aluminum intake has been studied in relation to neurotoxicity, and there is ongoing scientific debate about whether chronic dietary aluminum exposure contributes to Alzheimer's disease risk. EFSA's 2008 review of dietary aluminum exposure concluded that the tolerable weekly intake (TWI) was being exceeded by some European populations based on total dietary aluminum sources, raising concern. A 2011 EFSA risk assessment noted that certain high-aluminum sources (including baked goods from SALP-containing leavening agents) contributed meaningfully to total dietary aluminum. The WHO has set a PTWI (provisional tolerable weekly intake) of 2 mg/kg body weight/week for total aluminum. However, the causal link between dietary aluminum from food-grade SALP and Alzheimer's disease has not been definitively established in human studies.