Just How Dangerous is BPA?

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Almost everyone by now has at least some familiarity with BPA in plastic, especially if you have kids. For those of you that are not familiar, here is the media narrative on BPA. BPA is an additive that is used in plastic materials. This additive causes horrible health problems but the evil chemical industry won’t remove it and the FDA must be being bought off by the same evil chemical industry to continue to allow its use. In fact the whole obesity epidemic might be the fault of BPA and thus the evil chemical industry.

Don’t believe that that is the narrative? Check out this Newsweek article.

Now, let’s talk about the reality of BPA.

First, let me explain what BPA is. BPA stands for Bisphenol A. I don’t want to get too much into the chemistry of BPA because, unless you’re an organic chemist, it will all be Greek to you. BPA is a crystalline solid material that is white in color. It is used for a number of applications but for the purposes of this article we will be talking about its use in plastics.

BPA is used as a monomer in the polymerization of two different plastics, polycarbonate and one type of epoxy. BPA is not an additive that is added to plastic to change its properties, it’s a basic building block. When plastic is made, a monomer undergoes a chemical reaction to become a polymer. Mono is a prefix indicating single and poly is a prefix indicating many. Polymer is just another name for plastic. In other words, BPA cannot be removed or replaced with some other chemical. It is a fundamental part of these two plastic materials.

Let me just say this again: despite the scare tactics, BPA is only in two types of plastic. Polycarbonate plastic is a very expensive, very high impact crystal clear plastic that is used for everything from eye glass lenses to some reusable water bottles and at one time baby bottles (more on that later). Polycarbonate is not and has never been used for soda bottles or for bottled water that you would buy at the grocery store. It is way too expensive for that. Disposable type containers like that are made of a different plastic called PET which does not contain BPA. They always have been. Check them yourself; they will have a recycling code of #1 on them which is for PET. Also plastic drinking cups (think Solo cups) have never been made from polycarbonate. They are and have always been made from polystyrene (again no BPA). Polycarbonate may be used for things like vessels for blenders, food processers and juicers and for reusable sport bottles.

Containers that have never been made from polycarbonate and thus contain no BPA:

  1. Bottled water bottles
  2. Soda pop bottles
  3. Food storage containers such as Rubbermaid or Tupperware
  4. Plastic drinking cups like Solo.
  5. Bottles for things like dish soap or cleaners
  6. Containers for peanut butter or mayonnaise

Containers that might be made of polycarbonate and thus contain BPA:

  1. Reusable plastic water bottles
  2. Baby bottles prior to 2012
  3. Infant training cups (sippy cups) prior to 2012
  4. Some plastic pasta cookers such as Pasta Express
  5. Some containers for blenders, food processors and juicers.

The bottom line is that you are not consuming as much BPA as you might think.

BPA is also used in one type of Epoxy. There are many other types of epoxy that do not contain BPA. This makes the epoxy different from polycarbonate. Epoxy is a more general term and so there are in fact epoxies that do not contain BPA. All polycarbonate does. As far as food contact applications, some BPA Epoxy is used to line the inside of steel cans to prevent them from rusting. Cans that contain baby food or formula have not been lined with this type of epoxy since 2012.

Where does the BPA come from?

Interestingly, when polycarbonate is polymerized, some residual BPA remains un-reacted in the plastic. Studies have found that between 5-80 parts per million (PPM) un-reacted BPA remains in polycarbonate. You would think that this would be a problem but in fact, studies show that there is no relation between un-reacted or residual BPA and the amount of BPA that leaches into food and beverages. What happens is that water has a very slight chemical reaction with polycarbonate and BPA is one of the products of this reaction. Because all beverages and food contain some water, this reaction happens whenever polycarbonate comes into contact with them. BPA leaching from BPA-Epoxy works in a similar way.

Many studies have shown that food and beverages stored in containers made from PC will contain around 5 parts per billion (PPB) of BPA and around 37 PPB for BPA-Epoxy lined cans.

Health Effects

BPA exhibits estrogen mimicking hormone like properties. It is considered an endocrine disruptor. The bottom line is that any chemical that mimics hormones or blocks hormones can cause all sorts of negative health effects. These health effects are primarily sexual development problems but some studies have also linked BPA intake to learning disabilities, attention deficit disorder, deformations of the body, breast cancer, prostate cancer, obesity and diabetes.

These are very scary health problems which are made even scarier when the FDA reports that infants have a higher intake of BPA than adults.

BPA is one of the most studied chemicals in history. Literally thousands of studies have been performed, mostly on rodents.

What Does The FDA Say?

Looking at the health concerns above, you might be shocked to learn that the FDA still allows BPA containing plastics to be used in food and water contact applications. The FDA still considers BPA in small amounts to be safe. They continue to study BPA’s effects on humans and monitor intake amounts. The FDA did however ban its use in baby bottles, infant training cups and linings for cans for baby food and formula in 2012. It seems slightly contradictory to claim that this chemical is safe but ban its use for babies and infants. The FDAs official position is that: “an adequate margin of safety exists for BPA at current levels of exposure from food contact uses”.

The FDA completed a safety assessment of BPA in 2014. You can view the full report here (PDF). I will try to take you through it in laymen’s terms and explain what their official position on it is.

Here is the current level of human intake according to the FDA in their most recent review.

Age                        Average Intake*       Upper Range of Intake**

>2 Years              0.0002                                0.0005

1-2 Years            0.0005                                0.0011

0-1 Years            0.0003                               0.0006

        *All intakes in mg per kg of body weight per day

         **90th percentile

In its 2014 review, the FDA concluded a 4 year review of 300 studies on BPA exposure in rodents. From this review they determined what they call the No Observed Adverse Effects Level (NOAEL). This is the amount of daily intake that is considered safe for rodents. The NOAEL is determined using a statistical analysis of the studies that are reviewed. The current NOAEL for BPA in rodents is 5 mg per kg of body weight per day according to the FDA findings.

Based on the daily intakes above and the NOAEL for rodents, the FDA calculates what they call a Margin of Exposure (MOE) which is sometimes referred to as the Margin of Safety (MOS). The MOE is calculated by dividing the NOAEL by the human intake number.

Age                                        Margin of Exposure (MOE)

>2 years                               10,000

1-2 years                              4,545

0-1 years                              8,333

The FDA considers an MOE of over 1000 acceptable. This means that the FDA is comfortable as long as daily human intake is less than 1/1000th of what is considered safe for rodents. In the case of some other chemicals, the FDA looks for an MOE of over 100. This means that the FDA is being more cautious with BPA than other additives or contaminants in food.

Even though according to the FDA, BPA intake is currently at a safe level, they did take the additional step of banning PC and BPA-Epoxy for use in items that would contain food and beverages for infants. I think that they did this because the BPA intake for infants, especially between 1 and 2 years old was so much higher than any other group. They probably were concerned that this could be a trend and decided to put some restrictions in place. In my opinion, this is another example of the FDA playing it very safe.

There is another reason to believe that the FDA is playing it very safe. The MOE of 1000 is probably way more than is needed to ensure safety. Studies have shown that humans metabolize BPA much easier than rodents. Studies on humans have shown that suddenly using polycarbonate containers for beverages produces a large increase in BPA presence in urine. This sounds bad, but the presence of BPA in the urine means that the human body is getting rid of it as a toxin and not absorbing it which would be worse. Rodent’s digestive systems are not as good at removing toxins as human digestive systems are.

The point is that the FDA is erring way, way, way on the safe side here.

There are some arguments on the other side of this issue. Let me address some of them.

Some studies show that even extremely small doses of BPA can cause major health problems in rodents

The biggest problem is that only a few studies actually show adverse health effects for extremely low doses. Thousands of studies have been performed and the results of the studies range from very little effect to massive effect. The results of the studies form a bell curve. The FDA considers results from the studies too far from the average result to be outliers. This is a very common statistical technique for evaluating data. Data that is more than two standard deviations away from the mean is considered an outlier. Those results are typically discarded.

It should also be noted that the studies that use rodents typically involve giving massive doses of the chemical to the test subjects. Scientists do this because they want to get a result. They want to see how much of a dose it takes to cause health problems. You have to keep that in mind when you read about these studies. The scientists are not trying to scare people by giving mega doses of harmful chemicals, this is how you determine if there are in fact harmful effects.

Some studies show large amounts of BPA present in human blood samples

The problems with these studies are the same with the low dose studies above. Only a few studies have shown this. There is a significant amount of BPA that is in the environment (especially in dust) mainly because it is used in paper. Laboratories find it difficult to keep blood samples clean enough to yield good results.

FDA corruption

A lot of articles claim that the FDA is corrupt and has been bought off by “big BPA” or some such thing. I am one of the biggest critics of government that there is but I still need to see some evidence here. Most of the studies that are performed are carried out at publicly funded universities. They would be susceptible to payola as anyone else. Maybe the manufacturers of PET are paying off the laboratories to produce studies that show the harmful effect of using polycarbonate. All joking aside, the FDA has decent transparency on this. They publish their findings and all of the studies that they review for the public to see. You do not have to file a freedom of information act request to see them; you can find all of the documents on the internet.

The great thing about conspiracy theories is that they are very difficult to disprove.

Conclusion

There are a few things to take away from this.

  1. BPA is not in every plastic. In fact, it is only in two plastics, polycarbonate and one type of epoxy. Polycarbonate is only used in durable reusable plastic items. Items that are made from polycarbonate will be stamped with a number 7 recycling code on them. If PC is used on your blender or juicer container, your food is not in there long enough to absorb a significant amount of BPA. You do not have to worry about disposable plastic containers; they are never made from polycarbonate.
  2. The amounts of BPA that we’re getting in our diet is extremely low but there is reason for some concern regarding the amount that children from 1-2 years old are getting, at least at the high end of the amounts that they are getting. I would expect that these amounts will drop since the FDA has banned PC and BPA-Epoxy from items that contain food and beverages for infants. People over 2 years old have a daily intake of BPA that is 1/25000th of the amount considered safe for rodents.
  3. Because of bad publicity, BPA containing plastic has been removed from most food and water containers and many items that still contain BPA have warning labels. I would expect that BPA intake levels are dropping and that trend should continue.
  4. If you are really concerned about BPA, look for BPA free items but trust that very few of the food containers that you buy have any BPA in them anyway.

My personal opinion is that the FDA is not only handling BPA regulations in a responsible way, they are in fact erring on the side of extreme caution. I completely understand however, anyone, especially people with young children or infants, not wanting to take any chances.

In addition to the FDA regulations, market forces are working here. BPA is something that is pretty easy to avoid if you want to.

There has been a lot of irresponsible reporting about BPA which has made it more difficult for consumers to make informed decisions about plastic items or food stored in plastic packaging that they purchase. Oddly, in the case of polycarbonate, part of the media narrative is not met. Polycarbonate is not an inexpensive additive that evil corporations use to save money at the expense of your health. Actually polycarbonate is one of the most expensive clear plastics in the market. It is usually chosen because of its high quality compared to other materials. Similarly, the epoxy lining in cans improves the safety of the contents by preventing the can from corroding as fast.

References:

  1. 2014 Updated safety assessment of Bisphenol A (BPA) for use in food contact applications (PDF)
  2. 2008 Draft assessment of bisphenol A in food contact applications (PDF)

3. Newsweek article about BPA.

 

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