Perfluorinated Compounds (PFAS) vs Dimethylpolysiloxane: which is worse?

What is Perfluorinated Compounds (PFAS)?

Per- and polyfluoroalkyl substances (PFAS) are a large family of synthetic chemicals characterized by extremely strong carbon-fluorine bonds. They are used in food packaging (grease-resistant coatings), non-stick cookware (PTFE/Teflon), food processing equipment, firefighting foam, and many industrial applications. The 'forever chemicals' moniker reflects their extreme environmental persistence.

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.

Documented risks

Perfluorinated Compounds (PFAS): PFAS are among the most extensively studied and harmful groups of synthetic chemicals in the modern environment. Their unique carbon-fluorine bond stability means they do not break down in the environment or in human body tissues — contributing to bioaccumulation over a lifetime. Health effects documented in human epidemiological studies include: - Cancer: PFOA (perfluorooctanoic acid) and PFOS (perfluorooctanesulfonic acid) have been associated with kidney cancer, testicular cancer, thyroid cancer, bladder cancer, and non-Hodgkin lymphoma in occupationally exposed workers and community members with contaminated drinking water. IARC classified PFOA as Group 1 (human carcinogen) in 2023 and PFOS as Group 2B. - Endocrine disruption: PFAS disrupt thyroid hormone signaling and sex hormone balance. Multiple studies find associations between PFAS exposure and hypothyroidism, early puberty in girls, and reduced sperm quality. - Immune suppression: studies have found that PFAS exposure is associated with reduced vaccine response in children and adults, suggesting PFAS may impair immune function. - Developmental effects: prenatal PFAS exposure has been associated with lower birth weight, developmental delays, and reduced immune response in infants. - Cholesterol: PFAS exposure consistently raises LDL cholesterol levels, increasing cardiovascular disease risk. The 2023 EPA MCLG (maximum contaminant level goal) for PFOA and PFOS is zero — reflecting the agency's conclusion that there is no safe level. The EPA set enforceable MCLs in drinking water in 2024. The DuPont/3M PFOA/PFOS contamination of drinking water in communities near Teflon manufacturing facilities led to a $671 million settlement (DuPont/Chemours, 2017) and $10.3 billion 3M settlement (2023) — among the largest environmental contamination settlements in history.

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.