What is Bisphenol A?: The Structure and Properties of the Chemical Compound BPA

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chemical structure of bpa

The controversial chemical, bisphenol A or BPA was little known until the recent baby bottle controversy, however it has been used for over 50 years and was first synthesized at the University of Marburg, Germany by Thomas Zincke in 1905. BPA, a chemical building block used to create epoxy resins and polycarbonate plastic, became one of the most important commercial chemicals with an estimated 2 million metric tons produced worldwide every yearand with an increase in demand of 6-10% yearly.

BPA Improves Plastic Products

The extensive production range of BPA in consumer products is due to its excellent physical and chemical properties. BPA’s polymer, polycarbonate, has the unique ability to combine toughness, good transparency, and elevated mechanical strength into a lightweight and high performance plastic. However, the health and environmental concerns arose because the polycarbonate is not stable when conditions such as heat, bases or acids are present.

This volatility is due to the linking bonds (ester bonds) between BPA molecules which are easily broken down under such conditions. This results in a high probability that BPA will leach from the plastic into the body and the environment. Unlike the risks of lead and mercury, the harmful effects of plastics was not generally recognized by the public until recently. The BPA leached from the plastics into food and water which is then consumed by humans can lead to disruptions associated with endocrine hormones.

The Chemical Structure of BPA Contains Phenol Groups

The chemical structure of BPA contains two phenol groups (-Ph-OH) which makes it moderately soluble (120 to 300mg/L at pH 7.00). This chemical property is important to understand the impact of BPA on the environment and its health effects. BPA leaching from plastic contaminates food and water that people and animals consume.

BPA is not Easily Detectable in Water, People

In humans, this chemical can lead to diseases such as breast cancer and thyroid dysfunction. BPA present in industrial effluents, wastewater and landfills pollutes the land, groundwater and surface water. This leads to toxic uptake in agricultural products and bioaccumulation in aquatic organisms. Hence, measurable quantities of BPA should theoretically be found in affected rivers and organisms.

 

However, experimental findings indicated that BPA is undetectable due to two primary reasons. The first is the concentration of BPA in the samples is lower than the detectable limit of approximately 0.001ug/L. Secondly, in environmental samples, BPA has a relatively fast rate of degradation. Wastewater plants are able to remove about 95% of the original BPA. Therefore, BPA is undetectable in environment and its bioaccumulation is not obvious.

 

What is Bisphenol A?: The Structure and Properties of the Chemical Compound BPA

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