A long established Tetenal product bringing economy and reliability to the home processor. Protectan is a heavier than air inert gas that protects all types photographic developers and other solutions that degrade when exposed to air.
A quick spurt of Protectan in to a part used bottle will give a clear odourless heavier than air inert gas layer that will sit on top of the developer. The inert gas displaces the air forming an antioxidant seal. This protects the developer from oxidation and considerably extends the usability life.
Can be used with any photographic chemical. Some users have been know to spray it in to their vintage Port to keep it fresh.