PPSU - Is it Safe in Distillation - Case Study and Research on Polyphoenix Distllation Hardware

When a plastic resin is used in a new application it should be tested thoroughly over a long period of time to qualify its performance.  As many polymers have issue with leaching is really our duty to our customers to ensure that all products sold are safe to use long term without any risk of hazardous chemicals leeching into the final beverage.

PPSU is a resin type that was invented in 1970 and has been independently researched for a long time however due to the prohibitive cost it's only used in applications where it's necessary.

The reason why PPSU was chosen as an ideal candidate for distillation was for several reasons:

Plasticisers are often spoken about as being a major concern as they mimic human hormones and the migration of these plasticisers are one of the key health concerns.  This is also why KegLand does not sell vinyl beer lines.  PPSU is synthetically manufactured and completely free of plasticisers making it impossible for these to leach into the beverage as they do not exist in the resin in the first place.

Generally speaking many plastics become more unstable at closer to their glass transition temperature.  This is also when plastics can possibly break down faster and when leaching is more likely to occur.  As distillation occurs for most products under 100C we still have a considerable safety factor between 100C and the glass transition temperature which is above 220C.  So even if parts of the plastic were to contain elements that could leach out (which there isn't) the chance of this happening is substantially mitigated.

We performed extensive testing on the PPSU resing and exposed the resin to ethanol at boiling point for extended periods.  The final ethanol was extracted after days of contact at elevated temperatures then put through GC analysis to detect for any form of leaching.   The original ethanol was then compared with the control from the still which showed even after many days that there was no detectable leaching whatsoever and no detectable difference in the control and spirit that has been in contact with the PPSU.  In fact when the same test was done on copper and stainless steel there was a higher degree of contamination in the results than with the PPSU as some of the metallic elements of stainless can copper were found in the end product including trace elements of heavy metals especially in the copper sample.  Copper is also already known as being a catalyst to create ethyl carbamate in the distillation process which is potentially far more harmful than anything that we have found to come from the PPSU resin.  So it's quite probably that PPSU is not only safe but safer then copper or other metallic stills.

The same grade of PPSU resin that we use has also been through many other forms of independent testing and is now seen as the gold standard for baby bottles, medical and dental equipment, laboratory hardware for similar reasons as explained above.