Study: Cooking with polyamide plastic utensils may pose risks to liver and thyroid health

13 Nov 2019 --- Cooking with plastic utensils such as spatulas, whisks and kitchen spoons could pose health risks to liver and thyroids, according to a study conducted by the German Federal Institute For Risk Assessment (BfR). The toxic components are oligomers, composed of simple plastic building blocks and are unintentionally created in plastic production. The BfR recommends keeping the contact time with hot foods (above 70 °C) short when using polyamide (PA) kitchen utensils, but does not advise to refrain from their use in general.

“When the BfR conducted a first risk assessment in 2018, there were almost no toxicological data available for the cyclic polyamide oligomers. Hence, the BfR had to rely on in silico predictions based on the chemical structures of the substances,” Dr. Stefan Merkel, Head of the Unit Safety of Food Contact Materials at the BfR, tells NutritionInsight.

Thereafter, on request of the BfR, polyamide-producing companies commissioned toxicological studies according to international guidelines and submitted them to the BfR. Based on the results of these studies, a significantly more sophisticated risk assessment could be performed.

The BfR evaluated risks resulting from the migration of cyclic PA oligomers from kitchen utensils made from PA during cooking. The study revealed “possible” health damage to those regularly intaking oligomers via plastic utensils. Although the assessment concluded the risk to be “slight,” the research institute aims to conduct further research. The BfR has yet to find a correlation between plastic utensils and the toxicity of life-long ingestion, carcinogenicity and reproductive toxicity. The research institute encourages further research to be conducted on the long-term effects of plastic utensil usage while cooking. Moreover, it identified a similar need for research on the absorption into the body and for distribution, metabolism and excretion. 

The research institute warns consumers to be wary not only of PA plastic kitchen utensils, but of other sources of PA oligomers, for example, artificial casings and food packaging. The exact contents of plastic packaging are often unknown, which makes it difficult to ensure safety standards. The BfR has called upon producers of food contact materials to provide it with toxicological data according to the specifications of the European Food Safety Authority (EFSA). 

Harmful plastics?
“This BfR study does not advise to refrain from the use of kitchen utensils from polyamide during cooking. The BfR advises to reduce contact time of the utensils with hot and especially boiling, food. For example, a kitchen spoon from PA should not be left in a soup during the cooking process of the soup, but only be used for the occasional stirring of the soup,” Dr. Merkel concludes. 

The world as we know it has incorporated plastic usage in nearly all aspects of daily life, but the risks it may pose to human health have largely flown under the radar. Potentially dangerous plastic intake is not limited to cooking – researchers have also found traces of microplastics in water streams and aquatic systems. 

Echoing the conclusions of the BfR’s study, a report from the World Health Organization (WHO) found that the health risk of microplastics appears to be low. However, the health agent called for more substantial research to be conducted to confirm that the health effects of microplastic exposure indeed remain minimal. 

PA oligomers are not the only plastic components that have piqued industry’s attention. The General Court of the EU has listed bisphenol A (BPA) as a substance of “very high concern” on account of its properties that are toxic for human reproduction. 

Meanwhile, harmful Per- and polyfluoroalkyl (PFAS) chemicals have also been found in takeout food packaging from several leading US grocery stores. Last year, Whole Foods was prompted to remove all the packages cited in the report, as five of the 17 materials from the supermarket tested positive for the chemical. 

Translated and written by Anni Schleicher