It was recently reported that the six largest manufacturers of baby bottles will stop selling bottles in the US made with bisphenol A, or commonly known as BPA – a chemical that is widely used in plastics but increasingly linked to adverse health effects.

This happened after Connecticut attorney-general Richard Blumenthal, joined by the New Jersey, attorney-general, wrote to the bottle-makers and asked them to voluntarily stop using the chemical. Blumenthal was quoted saying, ‘The evidence seems too clear and emphatic and unequivocal to say we should simply permit this stuff to go into children on a massive scale.’

Blumenthal also said that he is gathering support from other attorneys-general to demand that manufacturers take BPA out of infant formula cans and all food and beverage containers. (Our Malaysian attorney-general might also consider speaking out strongly on such issues to initiate action to protect Malaysian public health and environment.)

Bisphenol A has been used commercially since the 1950s. It is used in the manufacture of some polycarbonate plastics, such as clear, hard water bottles and baby bottles. The chemical is also used when making resin coatings for the linings of some metal cans.

This chemical was detected in 93 percent of 2,517 Americans age six and over, tested by the US Center for Disease Control and Prevention (CDC) in a study released last year. In April last year, the US National Toxicology Programme released a draft report expressing concern that BPA could cause behavioral changes and affect brain development in foetuses, infants and children and trigger the early onset of puberty in females.

BPA mimics the hormone estrogen and may disturb the body's endocrine system. Chemicals like this are commonly known as endocrine disruptors or EDCs. Over the past decade, it is reported that more than 130 studies have linked BPA to breast cancer, obesity and other disorders.

In September 2008, a study found that adults with higher levels of BPA also had elevated rates of heart disease, diabetes and liver abnormalities. Before this, researchers at the Yale School of Medicine linked BPA to problems with brain function and mood disorders in monkeys.

One other study found that BPA can alter the activity of genes in normal breast cells in ways that resemble what is found in extremely dangerous breast cancers.

The study, conducted by researchers in California and published in the journal Cancer Research , found that many genes in non-cancerous breast cells exposed to trace amounts of BPA began acting in a way that closely resembled the gene activity in highly aggressive breast tumors that led to an increased likelihood that women would die of the disease.

New research suggested that BPA exerts an effect even at very low doses – lower than the safety standards previously set by the US Food and Drug Administration (FDA).

The daily upper limit of BPA that the US Environmental Protection Agency (EPA) earlier calculated as safe was 50 micrograms per kilogram of body weight. However, that standard is based on experiments conducted in the 1980s, before new studies emerged suggesting that serious health risks could result from much lower doses based on experiments in laboratory animals and in human cells.

Some studies report adverse health effects from exposures of only 0.025 microgram per kilogram of body weight per day. A polycarbonate bottle with room-temperature water may leach two micrograms of BPA per liter. A 3-month-old baby drinking formula from a polycarbonate bottle containing PBA may be exposed to as much as 11 micrograms per kilogram of body weight daily.

The European Food Safety Authority also concluded last year that the 50-microgram safety standard was sufficient. However, a panel of 38 experts from around the world convened by the National Institutes of Health (NIH) disagreed.

Their review of hundreds of studies over the past decade suggested a connection between exposure to BPA at levels typical in the US and increased rates of breast and prostate cancer, reproductive system abnormalities, and, for exposure in the womb, problems such as attention deficit hyperactivity disorder, obesity, and diabetes.

The FDA was said to have earlier maintained that BPA is safe, relying largely on two studies that were funded by the chemical industry. In October last year, the agency was faulted by its own panel of independent science advisers, who said the FDA's position on BPA was scientifically flawed. As a result, the agency was revisiting its position on the chemical.

In 2007, an expert panel using outside scientists minimised the health risks of BPA, but its findings were widely attacked after a congressional investigation found that a company hired to perform scientific analysis was also working for the chemical industry.

The US House Committee on Energy and Commerce was reported last year to be examining whether the proponents of BPA had paid consulting groups to engineer science that reaches predetermined conclusions.

A 2006 review reported published in the peer-reviewed journal Environmental Research showed that of 119 government-funded studies conducted as of July 2005, 109 found harmful effects from low-dose exposure in animals. By contrast, 11 industry-funded studies said that BPA causes no harm.

All these go to show that it is possible that certain parties, including official bodies, may not be fully informed or independent when taking stands in the interest of the public.

One interesting point to note is that although one company stopped selling baby products with BPA on Dec 31, 2008 in the US, it was reported that it will continue to market them overseas. This is a cause for concern as the Asian market, including Malaysia, may become a dumping ground for such unwanted products from the West.

In view of these latest developments, CAP has already written to the ministry of health calling for urgent action to immediately halt the sale of baby bottles and other food and beverage containers containing BPA here in Malaysia. Also, the sale of infant formula and other foods packed in tins or cans containing BPA.

In the meantime, consumers may want to take up the following recommendations made in the US as an immediate precaution:

• Identify which containers might have PBA. Polycarbonate is usually clear, rather than cloudy. If the container carries a recycling code, it will be marked with the number 7 or the letters ‘PC’ or both. No. 7 bottles made with BPA-free polyethersulfone (PES) won’t have the ‘PC’ marking. Other BPA-free plastic alternatives include polyethylene, which may be marked with recycling codes No. 1 (PET), No. 2 (HDPE), or No. 5 (PP- polypropylene)

The writer is president, Consumers Association of Penang.