Bisphenol-A (BPA) is a chemical used to make polycarbonate plastics. Polycarbonate plastic is tough and break-resistant and commonly used to make plastic-ware like water bottles, spoons, forks, containers, toys, mobile phones, and most importantly, baby bottles. BPA has been used in plastic making since the 1950s, but the adverse effects have always been suspected. Recent studies have started bringing harder evidence to the fore on the effects of BPA.
The US-government funded National Toxicology Program recently published a study that clearly acknowledged that what has been suspected may be of significant cause for concern. The study said that the primary exposure to BPA was through consumption of food and liquids stored in these containers. The chemical leached into the food from the plastic. Moreover, the hotter the food, it appears the higher the rate of leaching. The NTP study also cited other historical studies that showed that up to 93% of people in a test had BPA samples in their urine 1.
So what does BPA do to humans?
The final NTP study stated that it had "some concern" about the effects of normal everyday exposure to BPA on brains, behaviour and the prostate gland in foetuses, and children2.
These showed that exposure to high levels of BPA during pregnancy in rats1:
- Reduces survival rates of the foetus
- Reduces birth weight
- Reduces growth of offspring in their early years.
BPA is also what is known as a “synthetic oestrogen" - a chemical that can trigger an effect similar to the human hormone oestrogen. High levels of BPA also produced further effects in rats like cancers (including breast cancer), neurological and behavioural alterations (like hyperactivity) and early onset of puberty1.
Based on previous history we know that chemicals that produce adverse effects on laboratory animals usually tend to mimic them in humans over time. While the studies may take a long time to prove the direct link to humans, it is better we remain informed.
It must also be noted that none of the regulatory agencies in countries like US, Canada and the European Union have banned BPA yet but we also know that governments usually lock the stable door after the horse has bolted.
So what should we do? How do we know what has BPA in it or not? As we know BPA is a very common chemical in a number of everyday plastics. Most however, have little effect on us and only the ones we use for our food and drink should be of any concern.
In the US, Canada and the European Union, there has been a large scale move away from polycarbonate bottles, especially in baby bottles. These have been replaced by either glass bottles or by BPA-free alternatives. In several countries it is usually easy to identify polycarbonate bottles as they have a numbering scheme on the bottom of the bottle. The number 7 in the middle of the distinctive recycling triangle in bottles indicates that the plastic in it is of the kind “Other” and is usually polycarbonate. If it has the term “PC” next to it, it is definitely polycarbonate.
In India, where such identification is not always present, we can usually tell what is polycarbonate by the following characteristics of the plastic – clear, tough, hard, resistant to breakage, non-bendable. It is better to identify these and not use them for food. Replace these with other types of plastics (PET etc.) or with glass or stainless steel containers.
1. "Brief on Bisphenol-A(Draft) by the National Toxicology Program", National Institute of Environmental Health Sciences (part of the National Institutes of Health), US Government, Dated April 14, 2008
2. NTP-CERHR Monograph on the Potential Human Reproductive and Developmental Effects of Bisphenol-A, US Government, September 3 2008
Last updated: Sep 3, 2008