E900A - Dimethyl polysiloxane

At a glance

• Also called: polydimethylsiloxane (PDMS), dimethicone, silicone oil
• What it does: prevents and controls foam in foods and drinks
• Common places: frying oils, sugar processing, beverage and fermentation steps
• Origin: synthetic, made from silicon-based building blocks
• Diets: vegan, vegetarian, halal, and kosher friendly by nature (check brand policies)
• Heat and storage: very heat-stable and used at very low levels
• Regulation: permitted as a defoaming agent in the U.S. and EU

Why is Dimethyl polysiloxane added to food?

Food makers add dimethyl polysiloxane (PDMS) to stop foam from forming in kettles, tanks, and frying oil. Foam can trap air, spill over, slow production, and cause uneven frying; PDMS spreads on bubble surfaces and makes them collapse. In the United States, the Food and Drug Administration (FDA) allows dimethylpolysiloxane as a defoaming agent in food processing under specific conditions in Title 21 of the Code of Federal Regulations (21 CFR 173.340).¹

What foods contain Dimethyl polysiloxane?

You will most often find PDMS in:

• Frying oils used for snacks and quick-service foods
• Sugar and yeast processing, brewing and fermentation tanks
• Some beverages and syrups during manufacturing steps

In many cases it is a “processing aid,” used to control foam during production and present only in trace amounts in the final food. In the European Union, E900a is authorised as a food additive (functional class: anti-foaming agent) for use in various foods according to Regulation (EC) No 1333/2008.² In the U.S., its use as a defoamer during food manufacture is regulated in 21 CFR 173.340.¹

What can replace Dimethyl polysiloxane?

There are several ways to reduce foam if a product developer prefers not to use PDMS:

• Process tweaks: lower agitation, temperature control, and better tank headspace
• Equipment choices: spray balls, baffles, and fine filtration of oils
• Other additives with defoaming or de-aerating action, depending on the food: some polysorbates such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate, or polyoxyethylene sorbitan monostearate can help manage bubbles in certain systems
• Use of specially refined vegetable oils as “mechanical” antifoams

The best substitute depends on the product, process, and local rules.

How is Dimethyl polysiloxane made?

PDMS is a silicone polymer built from repeating “siloxane” units (–Si–O–Si–) with methyl groups attached. In industry, producers make it from silicon-based starting materials that are converted to small siloxane molecules and then polymerized to the desired fluid. EU additive specifications describe E 900 as polydimethylsiloxane and set identity and purity requirements for use in food.³

Is Dimethyl polysiloxane safe to eat?

Regulators have reviewed PDMS and allow its use at very low levels in food. The FDA permits dimethylpolysiloxane as a defoaming agent in specified applications, reflecting its safety when used as directed.¹ In Europe, the European Food Safety Authority (EFSA) re-evaluated polydimethylsiloxane (E 900) and concluded it does not raise safety concerns at the reported uses and use levels.⁴

Does Dimethyl polysiloxane have any benefits?

Its benefits are technological, not nutritional. By keeping foam down, PDMS helps foods fry more evenly, reduces boil-overs, and supports consistent quality in large-scale cooking and mixing. It can also help reduce oil splatter during high-temperature frying in commercial settings.

Who should avoid Dimethyl polysiloxane?

Most people do not need to avoid PDMS. However, you may choose to avoid it if:

• You prefer to skip silicone-based additives for personal or “clean label” reasons
• Your doctor advises avoiding specific additives If you have questions about a product, check the ingredient list or contact the maker.

Myths & facts

• “Silicone” is not “silicon.” Silicon is a natural element (a metal-like solid). Silicone is a family of flexible polymers made from silicon and oxygen.
• PDMS is used in many areas (like kitchenware and cosmetics), but food rules are separate. Only forms that meet food-grade specifications are allowed in foods in the U.S. and EU.³²
• The amounts used in foods are very small. Rules limit when and how much can be used, and safety evaluations consider these low levels.¹⁴

Dimethyl polysiloxane in branded foods

Many restaurant and packaged-food companies use PDMS in frying oil or during processing to control foam. Labels may list “dimethylpolysiloxane,” “polydimethylsiloxane,” or “dimethicone.” Availability and recipes vary by country, so check local ingredient statements and brand websites for the most accurate information.

References

Footnotes

1. 21 CFR 173.340 — Defoaming agents — U.S. Food and Drug Administration (eCFR). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-173/section-173.340 ↩ ↩² ↩³ ↩⁴

2. Regulation (EC) No 1333/2008 on food additives — European Union. https://eur-lex.europa.eu/eli/reg/2008/1333/oj ↩ ↩²

3. Commission Regulation (EU) No 231/2012 — Specifications for food additives. https://eur-lex.europa.eu/eli/reg/2012/231/oj ↩ ↩²

4. Re-evaluation of polydimethylsiloxane (E 900) as a food additive — EFSA Journal 2018;16(1):5083. https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2018.5083 ↩ ↩²