Oxygen absorbers: what they are, how they work and how to choose them

Oxygen absorbers, also called oxygen scavengers, capture O₂ inside a package or enclosure. They are used as part of active packaging to reduce residual oxygen, taking account of the food, its packaging and the manufacturer's instructions for the specific product.

Including an absorber does not in itself establish microbiological safety or guarantee shelf life. Package design and sealing, process control and the characteristics of the food all matter and must be considered separately.

The expressions 'oxygen absorber', 'oxygen scavenger' and 'oxygen remover' broadly describe products intended to remove oxygen from the product environment. Their wording does not by itself indicate distinct technical performance. The actual mechanism and capacity depend on the manufacturer's product documentation.

It is important to distinguish an absorber from a desiccant or an indicator. An oxygen absorber removes O₂, a desiccant targets moisture and an indicator gives a visual signal. These are different functions, even though more than one may appear in a packaging process.

According to Cichello's scientific review of food preservation, many conventional absorbers contain iron compounds that react with oxygen and oxidize. This reaction reduces O₂ when the absorber and package provide conditions that support its action.

Not all technologies use the same materials. Laboratoires Standa also describes organic, non-ferrous ATCO IL products, which it says are non-magnetic.

According to Laboratoires Standa, ATCO absorbers can act on oxygen surrounding the product, oxygen included or dissolved in it and oxygen entering through package permeability. Standa describes anoxic conditions below 0.01% residual O₂ as a range-level statement, not a guarantee for every application.

A desiccant aims to lower available moisture whereas an oxygen absorber removes O₂. These are different variables that may affect food degradation in different ways. The cited scientific review explains oxygen scavenging technology in food preservation.

The two products should not simply be substituted for one another. Some oxygen absorbers require moisture to become active, while others are designed for dry products or environments. Product suitability must be checked against the relevant manufacturer's instructions.

As a first physical estimate for a package containing air, the amount of oxygen initially in its headspace is approximately the volume of air in the package × 0.21, reflecting about 21% oxygen in ordinary air. This estimates only the initial gas fraction; it is not a ready-made specification for which commercial absorber to buy.

Other potential sources of O₂ must be considered: oxygen dissolved or trapped in the product and oxygen that may enter through the package material or seal throughout storage. The scientific review identifies these variables. A universal dosage table would ignore important differences between foods and packages.

According to Laboratoires Standa, the ATCO range spans capacities from a few millilitres to more than 2,000 ml of oxygen. Actual references and specifications should be checked in current product sheets.

High-barrier materials and reliable seals affect the subsequent entry of oxygen. An absorber may capture initial O₂ and, within its capacity, some of the oxygen passing through a package. Excessive continued ingress can prevent the expected reduction from being maintained.

That is why initial air volume alone is insufficient to choose a reference. Permeability, seals, storage duration and conditions must be reviewed alongside current technical documentation. We do not publish generic oxygen-transmission values or food compliance limits without a relevant product source.

According to Laboratoires Standa, ATCO oxygen absorbers are compatible with modified-atmosphere gas packaging technology. This statement concerns the general approach and does not guarantee suitability for every food, gas mixture or manufacturing process.

Capturing oxygen and measuring it are different functions. An analyzer documents a gas sample, an absorber acts on available O₂ and an indicator may provide a visual signal. These tools may complement one another but should not be described as equivalent.

A check can use oxygen indicators or a MAP gas analyzer when the procedure calls for headspace measurement. The indicator manufacturer must specify how its colours or signals are interpreted.

Our MAP oxygen analyzer guide explains how measurements differ from absorption. Neither an oxygen absorber nor a picture of an indicator substitutes for a quantitative measurement when a recorded residual O₂ value is needed.

Control y Suministros includes ATCO sachets, adhesive absorber labels and ATCO Box in its catalogue. A sachet is placed separately in the package; an adhesive label incorporates the absorber inside the package; according to the manufacturer, ATCO Box addresses anoxic treatment in larger volumes.

Standa describes pre-activated absorbers for dry products or environments and moisture-activated alternatives. The activation type must be established from the actual product sheet rather than inferred from a photograph of the packaging.

See the ATCO absorber range and our ATCO Box product page. Additional formats shown by Standa are not automatically part of our commercial offering.

We can advise on available formats by discussing the type of product, its packaging and the manufacturer's information. The initial oxygen calculation is useful background for that discussion but does not replace compatibility checks or the process trials needed to validate a preservation method.

According to Laboratoires Standa, its range works within a few hours and can continue absorbing oxygen until the package is opened; the actual conditions depend on the reference. Request documentation through the contact form.

How low can ATCO absorbers reduce oxygen?

According to Laboratoires Standa, its range can achieve anoxic conditions below 0.01% residual O₂ under suitable conditions.

How long do they take to work?

According to Standa, they act within a few hours and continue until the package is opened, depending on the reference and conditions.

What capacities are available?

According to Standa, its range extends from a few ml to more than 2,000 ml of O₂.

Can they be used with modified-atmosphere packaging?

Yes. Standa describes compatibility with MAP gas technology; each specific application requires checking the product sheet.

Are there non-magnetic oxygen absorbers?

Yes. Standa describes organic, non-ferrous ATCO IL products.

How do they differ from desiccants?

An oxygen absorber removes oxygen while a desiccant reduces moisture. They serve different purposes, according to the cited scientific literature.

What are oxygen absorbers made from?

Many contain iron compounds that oxidize; non-ferrous technologies also exist, according to the review and Standa.