Dimethyl polysiloxane

Dimethyl polysiloxane, commonly known as polydimethylsiloxane or PDMS, is a silicon-based polymer used in food primarily as an anti-foaming agent and release agent. It prevents the formation of stable foam in cooking oils, jam production, deep-frying operations, and fermentation vats. In cooking oil applications, a tiny quantity is sufficient to break surface tension and prevent foam that would otherwise splatter and burn in commercial frying. It also serves as a release agent in baking, preventing food from sticking to equipment, and is a component of some food packaging materials.

JECFA evaluated dimethyl polysiloxane in 1973 and established an ADI of 1.5 mg/kg body weight per day based on animal safety studies. At the very low concentrations used in food applications — typically a few parts per million — dietary exposure is well below the ADI. The compound is chemically inert, not metabolised, and excreted essentially unchanged from the body. Its exceptional stability across a wide temperature range makes it reliable under the high-heat conditions of deep-frying.

Dimethyl polysiloxane is approved throughout the EU and in most other food regulatory jurisdictions for use as an anti-foaming and release agent. On ingredient labels it appears as dimethyl polysiloxane, polydimethylsiloxane, or E900. It is also familiar to consumers under a different context: the same compound is used as an ingredient in silicone-based personal care products and industrial fluids, though food-grade PDMS meets different purity specifications. Its presence in cooking oils used for commercial frying means it may be encountered in fast-food products even when not explicitly listed as an ingredient in the final product. No significant consumer health concerns have been identified at approved use levels.