E946 - octafluorocyclobutane

At a glance

• What it is: a perfluorocarbon (PFC) gas with the formula C4F8, also called perfluorocyclobutane.
• What it does: works as a propellant in aerosol foods; it helps dispense the product.
• Where it shows up: specialty food sprays and whipped toppings in markets where it’s allowed; usage is uncommon today.
• Diet notes: vegan and allergen-free; adds no sugars, fat, or protein.
• Labeling: may appear as “E946” or “octafluorocyclobutane” on EU ingredient lists.

Why is octafluorocyclobutane added to food?

Food makers use octafluorocyclobutane as a propellant, the compressed gas that expels an aerosol product from its can. In the European Union (EU), it is listed as a food additive with specifications for identity and purity under the functional class “propellant.”¹

What foods contain octafluorocyclobutane?

You may find E946 in some aerosol foods, such as whipped toppings, cooking oil sprays, or other pressurized emulsions—mainly in regions where its use is permitted. It is far less common than other propellants and may not be present in most mainstream products. If used, it should be listed on the label as octafluorocyclobutane or E946.

What can replace octafluorocyclobutane?

Manufacturers often choose other approved propellant gases instead, including:

• nitrous oxide
• propane
• isobutane or butane
• carbon dioxide or nitrogen
• Inert gases such as argon, helium, or oxygen when technically suitable

Non-aerosol formats (pump sprays, squeeze bottles, or pourable products) can also remove the need for a propellant gas.

How is octafluorocyclobutane made?

Octafluorocyclobutane is an industrial perfluorocarbon gas manufactured to high purity for its intended uses. It is a colorless, odorless compound with the molecular formula C4F8 (perfluorocyclobutane).² For food additive use in the EU, its identity and impurity limits are set by official specifications.¹

Is octafluorocyclobutane safe to eat?

In the EU, food additives must be evaluated and authorized before they can be used in foods, and they must meet strict conditions of use and labeling.³ Octafluorocyclobutane appears on the EU list of food additives with specifications, which include purity requirements intended to protect consumers.¹ As a propellant gas, it does not provide nutrition and is not added for flavor; most of the gas escapes the container during dispensing.

Does octafluorocyclobutane have any benefits?

Nutritionally, no. Its benefit is technological: a consistent spray, stable foam, or clean dispensing from an aerosol can. Because it is chemically inert, it does not react with flavors or fats in the product during storage or use.

Who should avoid octafluorocyclobutane?

There is no specific consumer group singled out by law for avoiding E946. People who prefer to limit aerosol products in general (for example, due to fragrance sensitivity from other ingredients in some sprays) can choose non-aerosol versions. If you have questions about a particular product, check the label or contact the manufacturer.

Myths & facts

• Myth: “E-numbers mean a food is unsafe.” Fact: E-numbers are codes for additives that are evaluated and authorized for use in the EU, subject to conditions and labeling rules.³
• Myth: “Propellants make up a big part of what you eat.” Fact: Propellant gases mostly leave the can as you spray; only tiny amounts may remain dissolved in the food.
• Myth: “Octafluorocyclobutane changes the taste of foods.” Fact: It is an odorless, inert gas used for dispensing, not for flavor.²

octafluorocyclobutane in branded foods

Use of E946 is uncommon. Where allowed, it may appear on the ingredient list of certain aerosol whipped toppings or specialty cooking sprays. Many brands instead use more common gases like nitrous oxide, propane, or isobutane. Check the label for “E946” or “octafluorocyclobutane.”

References

Footnotes

1. Commission Regulation (EU) No 231/2012 — Specifications for food additives listed in Annexes II and III to Regulation (EC) No 1333/2008. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32012R0231 ↩ ↩² ↩³

2. Perfluorocyclobutane (octafluorocyclobutane) — PubChem, National Institutes of Health. https://pubchem.ncbi.nlm.nih.gov/compound/Perfluorocyclobutane ↩ ↩²

3. Regulation (EC) No 1333/2008 on food additives — European Union law on authorization, conditions of use, and labeling. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32008R1333 ↩ ↩²