Poly Alpha Olefin (PAO) in HEPA filter integrity test at HVAC qualification

Poly Alpha Olefin (PAO) is used in in HEPA filter integrity during validation of HVAC system in different pharmaceuticals. This is the best alternative of DOP which was previously used for the same purpose as PAO is subject to use. DOP was using long time for HEPA filter integrity test during HVAC qualification.

International Agency for Research on Cancer (IARC) has classified DEHP/DOP as carcinogenic 2B substance According to evidence from rodent studies which has also been identified carcinogen (cause cancer) for the human. For this reason scientist was trying to replace DOP for similar materials for a long time.

In 2021, JICA[Japan Air Cleaning Association] introduce a guideline to substitute the DOP[Dioctyl phthalate] with PAO[Poly Alpha Olefin]. PAO provides the same performance as provided by DOP additionally doesn’t provide any harmful/carcinogenic effect to human.

Food and Drug Administration[FDA] stated that the alternative aerosols are also suitable but it shouldn’t promote the microbial growth in the respective area. Generated aerosol ranges from PAO[Poly Alpha Olefin] is 0.1 to 1.0μm.

The aerosol generator, generate the PAO aerosol and subsequently passed through the HEPA[High-Efficiency Particulate Absorbing/High-Efficiency Particulate Arrestance/ High Efficiency Particulate Air having six types A, B, C, D, E & F] filter and then with the help of a Photometer the integrity is checked as 99.97% particle contains size 0.3 μm shouldn’t pass to the HEPA filter.

Chemically, PAO is the polymer of alpha-olefin which is the class of Olefins those contains double bond between first and second carbon of the polymer chains.  Poly Alpha Olefin is the mixture of dimers, trimers and tetramers of 1-octane, 1-decane and 1-dodecane in chemically.

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. PAO contains better lubrication properties and having greater viscosity compare to mineral oils. Poly-alpha-olefins have good lubrication properties and greater viscosity than mineral oils.

Poly alpha olefins are also used as a coolant in radiators and synthetic lubricants. Generally, the declared shelf life of PAO is 10 Years but when subject to open the container, the shelf life down to only one year. This is the best practice to protect PAO from direct exposure of sunlight and protect from UV light.

Why DOP[Dioctyl phthalate] banned?

Due to carcinogenic effect for human using of DOP [Dioctyl phthalate] was banned in pharmaceutical company, additionally DOP has the following significant effect which is also the major cause to ban the DOP.

Endocrine disruption

Causes endocrine disruption in male, act as androgen antagonist subsequently effect on reproductive system. Exhibits insignificant levels of reproductive function in adolescent males in Prenatal phthalate exposure. Chromatin DNA integrity and Sperm motility expressively reduce in PVC pellet plant where presence of higher airborne concentrations of DOP. Subsequent study has been proved that the significant exposure of DOP reduce the Chromatin DNA integrity and Sperm motility in men.

Development

Several studies have been shown that significant exposure of DOP has been change the sexual function and development in rats and mice. During pregnancy, excessive exposure of DOP disrupt development and placental growth in mice which cause premature birth, low birthweight, and fetal loss. Advanced levels of anxiety during puberty and hypertrophy of the adrenal glands may arise if excessive DOP exposure occur in neonatal mice through lactation.

Obesity

Intestinal lipases convert DOP to MEHP upon DOP ingestion then MEHP absorbed. MEHP is considered for the obesogenic effect. DOP is the possible disruptor for the thyroid function which have already verified by human studies and rodent studies. Subsequent exposure of DOP is significantly relevant with plasma thyroxine levels and patient with hypothyroidism inclined to to weight gain.

Cardiotoxicity

A minor dose of DOP predominately effect the activity of mice. The duration of the exposure of and clinical dose of DOP has the significant effect of the behavior of cardiac cell at culture. Cell face the slow propagation speeds with fractured wave fronts.

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