Pure oxygen gas, the same as air contains, used to keep fresh meat looking red and to extend the shelf life of packaged foods.
What is it?
Oxygen (O2) is a colourless, odourless gas that makes up roughly 21% of the air we breathe. As a food additive, it is produced industrially by liquefying air and separating its components through fractional distillation. The food-grade form is chemically identical to atmospheric oxygen.
What does it do?
Oxygen serves two functions in packaged food. As a packaging gas (modified atmosphere packaging, or MAP), it keeps the iron-containing pigment in fresh red meat in its oxygenated form, oxymyoglobin, which gives meat its familiar bright-red colour. High-oxygen atmospheres, typically 70 to 80% O2 combined with carbon dioxide, can extend refrigerated red meat shelf life from around two to four days to ten to fourteen days. At lower concentrations, it supports the continued cellular respiration of fresh fruits and vegetables without triggering anaerobic breakdown. Oxygen also acts as a propellant in some food-aerosol products, where it expels contents from a pressurised canister.
Where you will see it
Pre-packed fresh red meat (beef, lamb, pork) sold in supermarket trays is the most common use, keeping the surface visibly red through the film lid. Ready-prepared salads, cut vegetables, and some soft fruits also use oxygen-containing modified atmosphere mixtures. On a label it appears as "Oxygen", "E948", or within the phrase "packaged in a protective atmosphere".
What the science says
Dietary exposure from packaged food is very low
Oxygen has very low solubility in food, so very little of the gas used in packaging actually dissolves into the product and reaches the consumer. The 2025 EFSA re-evaluation concluded that dietary exposure from E948 as a food additive is negligible compared with the oxygen already present in air we breathe continuously. The original 1990 EU Scientific Committee for Food opinion noted that intake from packaging uses is insignificant against permanent human exposure to atmospheric oxygen.
The EFSA FAF Panel concluded that the use of oxygen (E948) as a food additive does not raise a safety concern, and that dietary exposure is very low due to the gas's limited solubility in food.
The EU Scientific Committee for Food stated that setting an ADI for oxygen used as a packaging gas or propellant is unnecessary, given that human exposure to atmospheric oxygen vastly exceeds any food-additive intake.
High-oxygen packaging promotes lipid oxidation in meat
Using high concentrations of oxygen in meat packaging preserves the red colour that consumers associate with freshness, but the same oxygen accelerates the oxidation of fats in the meat. This lipid oxidation produces off-flavours described as rancid and can shorten the window in which the product tastes good, even if it still appears visually acceptable. This is a product quality and shelf-life trade-off studied in the food-science literature, not a direct health risk from consuming the additive itself.
High-oxygen MAP maintained bright-red meat colour but increased lipid oxidation compared with vacuum packaging, producing elevated concentrations of oxidation by-products such as thiobarbituric acid reactive substances.
High-oxygen MAP of poultry was associated with significantly greater lipid oxidation and poorer sensory acceptability scores compared with vacuum or low-oxygen packaging conditions.
Where it stands with the regulators
Who should be careful
There are no known groups who need to avoid oxygen used as a food additive. It is not an allergen, not derived from animal sources, and does not carry any specific health restriction. Look for "packaged in a protective atmosphere" or "E948" on labels if you want to identify products that use it.
The honest read
Oxygen is one of the most straightforward substances in the approved additives list. It is the same gas found in air, produced by separating air industrially, and used in such small dissolved quantities in food that regulators in both the EU and UK have concluded no intake limit is needed. The main scientific conversation around it is not about toxicity but about a packaging trade-off: high-oxygen atmospheres keep meat looking red for longer, but they also speed up fat oxidation, which affects how the product tastes toward the end of its shelf life. This is a food-quality question, not a health question about the additive. Both the original 1990 EU committee assessment and the 2025 EFSA re-evaluation reached the same conclusion.
Related additives
Common questions
Is E948 banned in the UK?
No. Oxygen (E948) is approved for use in food in the UK under the assimilated version of EU Regulation 1333/2008 and is listed on the UK FSA approved additives register. It is permitted in all food categories at quantum satis.
Does high-oxygen packaging affect the nutritional quality or safety of meat?
High-oxygen modified atmosphere packaging (typically 70 to 80% oxygen) keeps fresh red meat visually appealing but accelerates fat oxidation in the product. This can produce rancid off-flavours toward the end of the shelf life and reduce concentrations of some fat-soluble nutrients. This is a product quality effect, not a consequence of ingesting the oxygen additive itself.
What foods contain E948?
Pre-packed fresh red meat sold in supermarket trays is the most common use, where a high-oxygen atmosphere maintains the bright-red colour through the packaging film. Cut salads, fresh vegetables, and some soft fruits are also packaged in oxygen-containing modified atmosphere blends. The label will say "packaged in a protective atmosphere" or list E948 or "Oxygen" in the ingredients.
Is E948 vegan?
Yes. Food-grade oxygen is produced by the fractional distillation of air, with no animal-derived materials involved. The gas itself is vegan and vegetarian. Note that the foods it is used to package, such as fresh meat, may not be.
Sources
- EFSA Panel on Food Additives and Flavourings (FAF): Re-evaluation of oxygen (E948) and hydrogen (E949) as food additives. EFSA Journal 2025;23(8):e9595
- PubMed Central full text: Re-evaluation of oxygen (E948) and hydrogen (E949) as food additives (PMC12329423)
- UK Food Standards Agency: Authorised Regulated Food and Feed Products for Great Britain - E948
- UK Food Standards Agency: Approved additives and E numbers
- Wikipedia: Modified atmosphere packaging
- Springer: Effect of high-oxygen modified atmosphere packaging on tenderness, lipid oxidation and microbial growth of cooked pork. Journal of Food Measurement and Characterization, 2017
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