Here is a statement from Napier's of London. they do warn UK'rs to be diligent and chronograph their rifle when using this product as it may put them over the UK limit.

The New UPH Hunter .22
simply the best performing airgun pellet of its type, it is designed to give consistent results in all std powered air rifles, both PCP and Springers. Every tin is pre treated with exactly the correct dose of Napier Power Pellet Lube, and they can be used straight from the tin. No need to sort or grade them, we have already done that for you. Expect improved accuracy, and consistency, it is likely that an increase in muzzle velocity will also be achieved. We recommend that UK airguns are chronographed occasionally to comply with UK power legislation.
Available in .22 cal 5.5 with a nominal weight of 14.5 Grains

Power Pellet Lube 10ml
A quite remarkable simple to use product that will improve accuracy with any pellet and on any type of airgun guaranteed.The unique complex formula does much more than lubricate, in fact it creates a chemical seal around the skirt of every pellet, ensuring that it will not skim or tear on the rifling of the barrel.
This is turn greatly improves the gyroscopic effect and results in improved flight, with dramatic improvement in accuracy.

And it seems they have a business relationship with AirArms

Napier is proud to be chosen by Air Arms for cleaners and lubricants used in manufacture and are the only product to carry their endorsement and recommendation. Now every new Air Arms gun supplied worldwide comes with an introductory sample of our oil


But so far I have not seen any claims about polymerization gases. Please post any info you have.