Phthalates found in food samples from well know Fast Food Chains

We all know that fast food is not the healthiest food that we can eat. Many people acknowledge that it is a ‘sometimes food’ due to its high concentrations of sugar and saturated fats and its high energy content. However, most would not realise that some brands of fast food have been found to contain toxic substances known as phthalates.

Both DnBP (di-n-butyl phthalate) and DEHP (di(2-ethylhexyl) terephthalate) are phthalates, which are mainly used as plasticisers; the substances added to plastics, like PVC (polyvinyl chloride). This is done to make the plastic softer, increase its durability, flexibility, transparency, and longevity. The plastics produced are primarily used for food packaging and food contact materials. DnBP is also an ingredient in most nail polish.

A recent study conducted at the Southwest Research Institute in San Antonio, USA, and published in the Journal of Exposure Science & Environmental Epidemiology, has discovered that fast foods such as hamburgers, chicken nuggets, chicken burritos and cheese pizzas contained phthalates. The food sampled was from popular US fast-food chains McDonald’s, Burger King, Domino’s, Pizza Hut and Chipotle. The method used during the sampling of the food was gas chromatography mass spectrometry (GC/MS). This is an analytical method able to identify different substances within a test sample.

The researchers discovered that 81% of the food sampled contained the phthalate DnBP, while 70% of the food sampled contained the phthalate DEHP. Other types of phthalates were also detected in the food samples, however, at a lower percentage.

Human exposure to phthalates such as DnBP and DEHP has been linked to reproductive problems, liver, kidney, and lung damage (asthma) and learning and attention problems in children. DEHP is a well-known male reproductive toxicant and has been shown to cause cryptorchidism (a condition in which one or both testes fail to descend from the abdomen into the scrotum), changes in testicular testosterone levels, altered development of genitals and low sperm count and quality.

The study found that the median average of phthalates found in the fast foods sampled was 2.51 mg/kg, while the maximum amount of phthalate found was 12.4 mg/kg. To put that into perspective, a chicken burrito is said to weigh 669g on average, so it could contain as much 8.3 mg of the phthalate DEHT. The fast foods containing meat were found to have the highest concentrations of phthalates in them.

Current EPA (Environmental Protection Authority) guidelines state that tolerable levels of phthalates consumption for humans are 0.05 mg/kg of body weight per day. That means for an 80 kg adult, they could tolerably consume 4 mg/day, while the level for a 20 kg young child would mean that consuming only 1 mg/day of phthalates is tolerable. The difference between what is tolerable for a child and an adult obviously varies considerable due to children being smaller and weighing less than adults in general. The chicken burrito that contained 8.3 mg of phthalates would therefore exceed the EPA guideline of a tolerable amount for both adults and children. The amount in the chicken burrito is a whopping 8 times what is tolerable for a young child, compared to the adult, which is 2 times what is tolerable for them to ingest in a day.

The EPA guidelines state that toxic levels of phthalates for humans are 4.8 mg/kg body weight. So, the toxic level for an 80 kg adult would be 384 mg/day and a 20 kg child would be 96 mg/day.

The study looked at the concentrations of phthalates in the gloves used by the food handlers at the fast-food outlets, however, the results did not indicate that the gloves were the only source of phthalates in the food sampled. The question then needs to be asked, how is the phthalates getting into the fast food? And, if it is so damaging to humans, why is it even allowed to be used in the production of plastics that come into direct contact with our food supply?

This body of evidence from the study, has prompted a consumer push for phthalate-free products and regulatory actions to limit the use of phthalates in commercial products in the USA. Unfortunately, very little about phthalates has been mentioned in Australia and is potentially reminiscent of its comparatively slow banning of BPA (bisphenol A) plastics in 2010. (Japan banned BPA plastic in 2003).

There are safer alternative substances available that can be used instead of DEHP and DnBD to plasticize PVC. One such alternative is ATBC (acetyl tri-n-butyl citrate) which is derived from citric acid and was listed in the Phthalates Action Plan of 2012 from the U.S. Environmental Protection Agency. This same document says that the EPA is concerned about phthalates because of their toxicity and the evidence of pervasive human and environmental exposure to them. It promises to take action as part of a coordinated approach with the Consumer Product Safety Commission (CPSC) and the Food and Drug Administration (FDA).  The recent study mentioned above was conducted earlier this year in 2021; so possibly some action on this problem is now long overdue.

The Commonwealth Government here in Australia, has committed to phase out single use plastic packaging by December 2022. This is certainly a step in the right direction; however, Australia should also be conducting their own research into the fast food served here to determine what levels of phthalates are present.

There is a significant level of fast-food consumption in Australia, with McDonalds apparently having more than 1.7 million customers in Australia every day. According to a Money Australia survey conducted this year, one hundred and forty thousand McDonalds Big Mac burgers are sold in Australia every day. The average weight of a Big Mac is 240g and could contain as much as 0.528 mg of phthalate DEHT. This would give a child half their tolerable amount of phthalate for that day. Another question that also needs to be asked, how is it even decided what constitutes a tolerable amount of phthalate for human consumption? Surely any level of toxic poison in our food is too much.