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Info Centre - NCT fact sheet on Bisphenol A
What is Bisphenol A?
Bisphenol A1 is a chemical which causes damage to animals and potentially humans during critical stages of their development. It can mimic the effect of the hormone oestrogen in the body. It binds with oestrogen receptors, but doesn’t replace the activity of oestrogen, interfering with healthy growth and body function. Animal studies have shown it affects reproductive, neurological and immune systems.
Babies are particularly vulnerable to hormone mimicking effects because they grow rapidly, both in the womb and in their early months and years.
Bisphenol A is one of the highest volume chemicals produced worldwide. It is used to make polycarbonate and epoxy resins. These products are used in bottles, toys, in the lining of some food cans and dental sealants. Bisphenol A has been shown to leach out of feeding bottles which are made from this sort of plastic, especially if they are scratched or contain hot liquids.
How to tell if a bottle contains BPA?
It is polycarbonate plastic (clear shatter proof plastic) bottles that have the number 7 in the recycling triangle on the bottle that can leach bisphenol A (BPA) into the liquid in the bottle, or bottles that have the letters “PC” near the recycling triangle. However, not all materials with the number 7 in the triangle contain BPA. To be sure, check with the manufacturer or go for a bottle that is clearly labelled ‘BPA free.’
There are plastic bottles on the market that do not contain BPA and glass bottles do not leach bisphenol A.
Bottles are less likely to leach BPA at room temperature. Heating bottles or pouring hot liquids into bottles and repeated washing - which creates scratches - increases the rate of bisphenol A leaching from bottles. However, it is important that formula milk is made up using water at 70 C because powdered infant formula is not sterile.
It is also important that bottles are cleaned thoroughly and sterilised to prevent illness in babies. Sterilising solutions may be more appropriate for use with polycarbonate bottles.
What is the expert opinion?
Different experts have different opinions.
It is clear that most of us carry BPA in our bodies; studies in the US have found bisphenol A in the urine of 93% of children and adults tested in 2003-04.2 Almost all exposure is through diet, and babies fed with formula are among the most exposed. Debate continues on what is the safe limit of this compound.
In September 2007, the European Food Safety Authority (EFSA) increased its Tolerable Daily Intake (TDI) of BPA to 50 micrograms per kg body weight per day. The TDI is an estimate of the amount of a substance, expressed on a body weight basis, that can be ingested daily over a lifetime without risk to health.
The EFSA's scientific panel estimated adults take in about 1.5 micrograms /kg bodyweight/day in their diet, well below their TDI. While babies’ bottles leach far below this level (5-8 parts per billion) in recent tests, other animal studies have found bisphenol A levels as low as parts per trillion have been found to alter cell function. (Parts per trillion is 1,000 times smaller than parts per billion).
In the US, a review by BPA researchers considered more than 700 peer-reviewed papers for the Expert Panel Examination of the Relevance of Ecological, In Vitro and Laboratory Animal Studies for Assessing Risks to Human Health. The review concluded that 'the wide range of adverse effects of low doses of BPA in laboratory animals exposed both during development and in adulthood is a great cause for concern with regard to the potential for similar adverse effects in humans'.3
A second panel convened by the US Center for the Evaluation of Risks to Human Reproduction (CERHR) concluded that there is “some concern that exposure to bisphenol A in utero causes neural and behavioral effects” in infants and children. However, it found “minimal” or “negligible” concern about other possible health consequences from exposure to bisphenol A.4
More recently, a report in the Journal of the American Medical Association found that Americans with the highest levels of BPA in their bodies were more likely to have cardiovascular disease, type 2 diabetes and liver enzyme abnormalities, although it is not clear whether the associations were causal.5
In a small prospective study, researchers in Japan reported that bisphenol A levels are higher in women with a history of repeated spontaneous miscarriages.6
Yet, the alternative view, from the European Food Safety Authority (EFSA), is that BPA is metabolised in humans so that it does not have the same effects shown in animal studies. They concluded that there was ‘no need for further information, testing or for risk reduction measures beyond those which are being applied already’.7
The EFSA considered that babies and children can convert bisphenol A to biologically inactive chemicals. A key aspect of their reasoning is that there are significant differences between humans and the animals used in the studies; specifically that people metabolise and excrete bisphenol A from the body far more quickly than laboratory animals.8
The Food Standards Agency (FSA) in the UK states: “Very small amounts of BPA can transfer from the packaging into food and drinks. It's possible that BPA might affect the hormone system in people's bodies. That said, there has been a lot of research carried out worldwide and there is still no conclusive evidence that these chemicals do have this effect in people.
Independent experts have calculated how much BPA can be eaten every day over a lifetime without it causing harm to our health. It has been estimated that the amounts we take in from food and drink are much lower than this level.”
In 2008 Andrew Wadge, the Agency’s Chief Scientist, explained that, in terms of BPA exposure, a three month old, bottle-fed baby, weighing 6kg would need to consume more than four times the usual number of bottles of baby formula each day before it would even reach the TDI.
For further information see the FSA website: www.eatwell.gov.uk/asksam/keepingfoodsafe/asksamstoringpreparing/#A457998
What is the NCT view?
The NCT is calling for manufacturers to remove bisphenol A from baby bottles as there are alternative plastics that do not contain BPA.
Although the level of risk is not certain, parents are largely unaware of this risk and do not know which bottles to avoid. This lack of awareness is concerning.
As a first step, it is important that bottles and other items that might reach a baby's mouth, are free from bisphenol A. We welcome the news that these products are being withdrawn, as a precautionary measure, in America and previously in Canada.
Should parents be concerned, they can log on to the NCT website for more information www.nct.org.uk
Feeding using a bottle
Baby feeding bottles can be used to give expressed breastmilk or formula milk to a baby when you are not with your baby to breastfeed or when you are using formula. There are many different types of feeding bottle on the market but there is no published evidence that shows any one bottle design is any better than another. Bottles may be made of glass or plastic.
Glass bottles
Glass bottles have the advantage of being clear so the milk inside can be seen and they are easy to clean and sterilise and are much harder to scratch. However they are heavy and may smash.Plastic bottles
Clear shatter proof plastic bottles have become more popular because they are less likely to create the dangers of shattered glass.Correct preparation of formula
It is important that formula milk is made up using water at 700C because powdered infant formula is not sterile and does sometimes contain harmful bacteria. If you would like to know how to prepare formula safely, please see the NCT Information Sheet on 'Using infant formula’ available at www.nct.org.uk and also available to buy from NCT Shop – www.nctshop.co.uk
Alternatives to feeding with a bottle
For babies from about 4 months a baby cup can be used for occasional feeds rather than a bottle. From 6 months most babies will be happy to use a cup for most daytime milk feeds. For very young babies especially where you do not want to interfere with the possibility of breastfeeding or for occasional use of expressed breastmilk or formula there are non polycarbonate feeding cups available.
NCT Shop stock milk storage bottles: www.nctshop.co.uk
Medela milk storage bottles are lightweight and shatterproof. They are made from polypropelene and safe for storing breastmilk. Also suitable for freezing. Available in a set of three.
*All Medela bottles & breast pump kits are 100% Bisphenol-A (BPA) Free
References
1 (2,2-bis(4-hydroxyphenyl) propane
5 Lang IA, Galloway TS, Scarlett A, Henley WEet al. Association of urinary bisphenol A concentration with medical disorders and laboratory abnormalities in adults. JAMA. 2008 Sep 17;300(11):1303-10. Epub 2008 Sep 16.
6 Sugiura-Ogasawara, M, Y Ozaki, S Sonta, T Makino and Kaoru Suzumori 2005. Exposure to bisphenol A is associated with recurrent miscarriage. Human Reproduction 20:2325-2329.
