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What’s in Your Mug
Analyzing plastic additives in food contact applications is becoming increasingly important
by Susan Meronek and Jack Hubball
Regulated chemicals show up in toys, food, and other places in our daily lives. Many of us start each day reaching for our handy travel mug for that first wonderful sip of caffeine. But do we ever think about which plastics went into that mug? Did the manufacturer who specified the design of the mug delve into the formulation of the plastic? What is the composition of the lid and the body of the cup? These questions may never have been asked. In many food packaging applications, these questions are never asked. Typically, specifications for “food-grade” plastic, shrink wrap, or bags are delineated, but no further analysis or testing is done on these materials. So the question remains, “What’s in your mug?”
AccuStandard asked this question when we made our last promotional product, a travel mug. With the wonderful, twisted sense of humor chemists have, we ordered several thousand mugs with the question on it, and we decided to find the answer.
We took samples from our travel mug and several others received as promotional gifts or purchased in retail stores. From each mug, we sampled a small piece of plastic and performed a thermal desorption/extraction, followed by an analysis using gas chromatography/mass spectrometry (GC/MS). The results were somewhat surprising.
In one mug, our analysis showed the additives dibutyl phthalate, dioctyl phthalate, oleoamide, and Irganox 1076, an antioxidant.
Curious to see if other familiar food containers contained plastic additives, we went into the kitchen. Using the same methods, we analyzed a plastic pasta sauce container. The results revealed dibutyl phthalate, terephthalate (polymer), dodecyl phthalate, and several organic compounds, including lauric acid, myristic acid, linoleic acid, palmitic acid, and stearic acid. Because many of these organic acids are commonly used as plastic additives, it was unclear whether they originated from the sauce or the container. Our analysis also revealed the presence of squalene, cholesterol, and an antioxidant, most likely Ethaphos 368.
Additives such as these can migrate from packaging into food. Adverse effects may range from mild (changes in the taste, color, or texture of a product) to severe (long-term health issues) for those consuming the food.
While this is certainly not a scientific study, and we used only a few samples from a few available articles, this experiment shows the presence of a variety of plastic additives. Many can have adverse health effects, and some have been banned or regulated for certain uses.
Phthalates, the most common contaminants we found, are some of the most newsworthy of the group. Many phthalates have been regulated for years in drinking water and waste by Environmental Protection Agency methods, including 8061, 8270, and 525.2. Some phthalates have been banned in the European Union by directives such as 2005/84/EC. Under the current law, three phthalates will be permanently banned in all toys and child-care articles: DEHP (di (2-ethylhexyl) phthalate), DBP (di-n-butyl phthalate), and BBP (butyl benzyl phthalate). Three others, DINP (diisononyl phthalate), DIDP (diisodecyl phthalate), and DNOP (dioctyl phthalate), will be banned from use in toys and child-care articles that can be put in children’s mouths. In the United States, many toy manufacturers specifically state that their toys are phthalate free.
Discussing the adverse health effects of phthalates can be as dangerous as discussing politics. The plastics industry states that phthalates have been used for years and that there are no cases of anyone having been harmed by using items that contain them. On the other hand, environmental groups refer to studies that show that phthalates can damage the kidneys, the liver, and sex organs in animals.
Phthalates make up just one group among the many classes and types of chemicals added to plastics to make them more appealing, more durable, more useful, or easier to process. Analyzing these additives in the final consumer product is a relatively new area of research. Traditionally, manufacturers have relied solely on their vendors to provide materials that meet health, safety, and production specifications. Recent reports of questionable food quality from some imported products and the recent recalls on toys, however, have shifted the focus. Now consumers are demanding tests of the finished goods to ensure their safety.
Keeping Tabs on Plastics
As compounding, manufacturing, molding, extruding, and even shipping these materials becomes more complex, testing the final product to ensure that no unexpected additives are present is even more critical. There is no doubt that plastics are an integral part of our modern lives, but their effects go beyond their desirability for a given purpose and extend into the areas of consumer health and environmental impact.
Regulatory agencies and the plastics industry need to work together to help minimize the hazards. As our world becomes more global, the front line responsibility to ensure quality and safety will fall increasingly on the name on the box, rather than on the overseas manufacturer. There will be increasing regulation and legal action and more analysis to meet these consumer and regulatory concerns.
Reference materials for these plastic additive technical mixes are now becoming available. AccuStandard has compiled a broad library of these materials—available as certified reference materials—and has written the soon-to-be-released Taylor & Francis CRC Press book, The Handbook for the Chemical Analysis of Plastic and Polymer Additives, to help the chemist correctly extract and identify additives present in plastic and polymer matrices.
Meronek is an environmental chemist and vice president of production with AccuStandard, Inc. in New Haven, Conn. Reach her at email@example.com or (203) 786-5290. Hubball is a forensic scientist in the CSP Forensic Lab and a consultant for AccuStandard, Inc.