Poly Alpha Olefin (PAO) Used in HVAC Validation : Pharmaguideline

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Poly Alpha Olefin (PAO) Used in HVAC Validation

Know more about the Polyalphaolefin (PAO) used in HEPA filter integrity test during HVAC system qualification including their molecular structure.
Poly Alpha Olefin (PAO) is used for HVAC qualification in pharmaceuticals. PAO is used as a replacement of the DOP (Dioctyl Phthalate) that was used for this purpose for a long time.

Dioctyl Phthalate is found as a carcinogen (cause cancer) for the human. Scientists were trying to find a material to replace the DOP for a long time. 

PolyAlpha Olefin Aerosol GeneratorFinally in 2001 Japan Air Cleaning Association (JACA) published a guideline to replace the DOP with PAO. It gives the equal performance to the DOP and doesn’t have any harmful effect on health. 

FDA also clearly says that alternative aerosols are also acceptable but they should not promote the microbial growth in the area. Therefore, it is recommended to replace the Dioctyl Phthalate with Poly Alpha Olefin (CAS #68649-12-7). The size of PAO generated aerosol ranges from 0.1 to 1.0 μm.

The PAO aerosols are generated by the aerosol generator and passed through the HEPA filter then the integrity is checked using a photometer. 99.97% particles having a size larger than 0.3 μm should not be passed through HEPA filters.

Poly alpha olefin is a polymer of alpha-olefin. Alpha-olefin is a class of olefins those have a double bond between first and second carbons of the polymer chains. 

alpha olefin
Molecular Structure of Alpha Olefin
PAO is a mixture of the dimers, trimers and tetramers of the 1-octane, 1-decane and 1-dodecane. Poly-alpha-olefins have good lubrication properties and greater viscosity than mineral oils. Poly alpha olefins are also used as synthetic lubricants and as a coolant in radiators.

The shelf life of the poly alpha olefin is 10 years in a sealed container but for the opened container it is one year. It should be protected from UV light and direct sunlight.

Ankur Choudhary is India's first professional pharmaceutical blogger, author and founder of pharmaguideline.com, a widely-read pharmaceutical blog since 2008. Sign-up for the free email updates for your daily dose of pharmaceutical tips.
.moc.enilediugamrahp@ofni :liamENeed Help: Ask Question

6 comments: Post Yours! Read Comment Policy ▼

  1. Is PAO can be used in ULPA filter integrity test where pore size is 0.12 micron in compare to HEPA 0.3micron

  2. Sir,
    Your guidelines are very informative and knowledgeable.
    Are your presentations available for training of officers in pharma specially in QC.


  3. What is downstream and upstream?

  4. Can you tell PAO test parameters


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