Breathing Bags™

The Original Oxygen Transfer Fish Transport Bag

Don't be fooled by other bags claiming to do what Kordon's Breathing Bags do - there are no "Second Generation Breathing Bags" that are produced from the same or improved material or that can claim the same Oxygen Transfer Rate as genuine Kordon Breathing Bags. 


Breathing Bags are a completely new approach to the shipping of live fishes, as well as aquatic invertebrates and aquatic plants, in plastic bags. The special plastic film used in the Breathing Bags generates the constant transfer of carbon dioxide out of the water in the bag through the walls of the bag, and the absorption of oxygen from the atmosphere through the bag walls into the water in the bag. This provides a constant source of fresh oxygen that fish and other aquatic specimens use to breathe.

Kordon ® Breathing Bags™ represent a new approach to the problems of shipping live fishes and other aquatic animals and aquatic plants, including over long distances or for extended time periods. The product development staff at Kordon, teamed with plastics chemical engineers, have taken a technology first developed in space/military research and refined it to produce the bags being offered today.


The Breathing Bags are constructed of a special film that has a micro-porosity that allows the transfer of simple and complex gas molecules through the plastic wall of the bag. Carbon dioxide and oxygen in particular, as well as other gases - are constantly passing through the plastic bag  via the micro-porosity.  In other words - the plastic has gaps so small that water molecules cannot pass through - yet gas molecules can move freely. This provides a true "breathing" bag in place of a non-porous "barrier" bag as is used in traditional plastic polyethylene bags. As long as there is a breathable atmosphere outside the Breathing Bag, the fish or animals inside will not run out of oxygen.

Carbon dioxide exits the bags at 4 times the rate oxygen enters the bags, thereby constantly purging the water of toxic carbon dioxide, and allowing oxygen to replace it in the water. Kordon has shipped millions of bags around the world  (termed "Sachets") containing living foods (tubifex worms, brine shrimp, daphnia, glass worms, etc.) for aquarium fishes using the Breathing Bag technology.  Hundreds of thousands of Breathing Bags have been used successfully to ship fishes, coral reef animals, and aquatic plants.


Prior to the invention of Breathing Bags, the only plastic bags available for shipping fishes and aquatic invertebrates were made of polyethylene and had created a non-porous "solid-film barrier bag". There was no porosity-mechanism to allow the passage of gasses through the bag wall. When using these "barrier" bags any oxygen required to sustain the life of the fish or other aquatic life inside the bag must - of necessity - be added as a gas inside the bag prior to sealing.

This process has many problems.

1 - High concentrations of oxygen can cause flammable conditions.

2 - The presence of oxygen gas inside the bag takes up a lot of valuable shipping space.

3 - Once the supplied oxygen is used up there is no more available - fish can quite literally drown in traditional old-fashioned "barrier-bags".

4 - A bag partially full of water with the rest filled with oxygen allows the contents to slosh during transport, stressing and possibly injuring fishes.

5 - Toxic carbon dioxide from the fishes' breathing builds up in the water, displacing the oxygen. The oxygenated air in the bags may not be satisfactory for fishes' breathing, because (particularly from sources in underdeveloped countries), the bottled oxygen may be contaminated.

IT IS TIME FOR A CHANGE: Time in the bag has always been the cause of losses in shipping live fish. With old, traditional air-chamber bagging methods there has always been a short  time span between bagging the fish and getting safely to their destination. You typically have a short time span allowed before the air in the bags is depleted of all available oxygen and the fish begin to deteriorate. Long distance fish shipping using the old methods has always  required periodic opening of the bags and adding of new oxygen.  With Kordon Breathing Bags fish have been sealed into bags and sent on long transfer trips that have lasted for 7 to 10 days with no re-bagging and no addition of oxygen.  The fish shipments  have repeatedly arrived at their destination with very low losses and healthy, non-stressed fish. The continual flow ow carbon dioxide out of the bag and oxygen into the bag allows for  safer shipping no matter how far the distance.

In comparison - using the Kordon Breathing Bags allows for no sloshing and no stress.  The Breathing Bags are sealed with as little air inside as possible.  Ideally only water touches the inner surface of the bag.  No air chamber of added oxygen means no slosh-zone and turbulant travel for the fish inside.  You can test this by laying a filled Breathing Bag on a flat surface and allowing the fish to settle down. Picking up one edge of the bag - you can roll it until it is totally reversed - upside down - yet the fish inside will not move at all.  No sloshing, no jiggling... no stress.  Less stress equals less losses  or injuries during shipping or transfer of live fish.

Item No. 50201 - Breathing Bag™ 7" x 14" (full case is 2000 pieces)

Item No. 50202 - Breathing Bag™ 9" x 16" (full case is 2000 pieces)

Item No. 50203 - Breathing Bag™ 12" x 19" (full case is 1250 pieces)