Ageless® Eye Oxygen-indicating tablets verify that all the oxygen has been absorbed from your package. They start off pink in colour but when opened and inserted into the package they will turn blue. Once the package has been sealed, and providing that there are sufficient oxygen absorbing sachets for the volume of air, the tablet will turn back to pink when oxygen concentration is below 1%. This will not happen instantly and may take some days. Flushing with Nitrogen gas will speed up the process, but in normal use squeezing out excess air before sealing will help.
The shelf life is limited and life within the package may not exceed six months. This unfortunately means you cannot rely on it as a monitor for oxygen within the package on a long term basis and it should only be seen as an indication that the Ageless or RP Agent has worked at the time of initial packaging.
A new generation of oxygen monitoring equipment is now available for the larger user. It is important to handle the sealed packages carefully as bad or careless handling can lead to the bag being punctured and oxygen leaking into the package. This is less of a problem with vacuum packed oxygen scavengers because it is immediately obvious when a vacuum pouch has punctured as it inflates and loses the rigidity created by the process of vacuum packing. Air contains 21% of oxygen and when this is removed by the scavenger a slight vacuum is created. This vacuum is another indicator that oxygen has been removed.
An oxygen indicating tablet will be blue in normal atmosphere and pink when concentrations of oxygen are below 1%. This colour change is reversible, so that a single Oxygen Indicating Tablet can be reused many times.