Tribunes

Food Security

J.J. Rodríguez Jerez

Grisc – Grup de Recerca en Gobernança del Risc (UAB)

Bisphenol A, is it a toxic?

2 October 2009

Photography: Prallin

The lack of synchrony between countries causes the prohibition of possible toxic substances in some and their authorisation in others. One example of such disparity has to do with bisphenol A (BPA), present in some materials that are in contact with food when used in the production of polycarbons (PC) or synthetic Epoxy-phenolic resins. It is a forbidden substance in some parts of America, whilst in Europe its usage is still allowed.

In fact, with the evidence that is currently available, one cannot conclude that there is no persistent toxic effect of BPA.

Differences in opinion

The European Food Safety Authority (EFSA) and its homologous British Food Standards Agency, FSA, have no plans to re-examine the established criteria (in 2003 and 2007) in relation to BPA. The European Authorities have confirmed its approval in materials that could be in contact with food, like food containers or sealants in the packaging, tins or drinks. The limit marked as safe in Europe remains, therefore, at the limits already approved by the organization in 2007, when it established a tolerable daily intake of 0.05 mg / kg body weight.

However, the equivalent Canadian and American authorities are revising the criteria regarding the same substance. During 2008, Canada was the first country that forbids the import and sale of baby bottles made out of polycarbonate that had BPA. Also, it allocated 1.7 million dollars towards the study of this substance.

Canada was the first to forbid the import and sale of baby bottles with polycarbon and BPA In the United States, in May 2009 the State of Minnesota joined the Canadian prohibition, followed by the city of Chicago. After these decisions, the States of California, New York and Connecticut are evaluating the possibility of also prohibiting these kinds of products. Also, the U.S Congress is evaluating the possibility of promoting a prohibition at national level.

In March 2009, six American manufacturers of baby bottles confirmed the joint decision to stop making products with BPA. After the decision, they exported the surplus to the United Kingdom, who allows the substance. The most important sellers or distributors of products for American children, such as Wal-Mart and Toys R Us, have said they will eliminate the distribution and sale of products aimed at children containing BPA.

Why the doubts

PC is a plastic widely used in different products: baby bottles, plastic plates and cups, plastics compatible with the microwave, plastic containers to keep food in the fridge, bottles for reusable water or plastic milk bottles.

The synthetic Epoxy-phenolic resins, on the other hand, are used as internal protective coating in cans or metal lids of glass jars or bottles. It is used in industrial areas or some water tanks, their use prevents the oxidation of the products.

The BPA is present in both PC and the resins discussed. In humans, ingested BPA is quickly transformed into glucuronide of BPA in the intestine and liver. This molecule is rapidly excreted in the urine, so that the average life of the BPA metabolized in our body is short, less than 6 hours.

But sometimes it has been pointed out that BPA may cause effects on the hormonal response. In this regard, the committee of products in contact with food from the EFSA said that in some rodents, particularly mice, secondary metabolites can be formed with a high estrogenic potential. For this reason a possible toxic effects has been suggested, especially in children.

However, this same committee of experts noted that the metabolism of mouse and human is significantly different at this point, therefore the reaction will not be the same in different species. Some studies point to the BPA at low doses and in animals susceptible to this substance may cause small changes in some organs, but in no case has there been shown that puberty is being advanced or that it induces hormone-dependent tumours.

For this reason, the group of experts of the EFSA points out that there is no scientific evidence that shows toxic activity in either children or adults, as long as the established limit levels are taken into consideration in commercial products. Not so for Americans.

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Eduardo 30/03/2010
El Bisphenol A, se comporta en el cuerpo como una hormona sintética que modifica el ADN humano produciendo mutaciones en el. Estas mutaciones son transmitidas a las próximas generaciones.

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