US Study Warns: Recycled Plastic "Washing Water" May Pose Health Risks, Experts Call for Stricter Regulation

According to the latest research report released by the Institute of Food and Nutrition Science on March 9th at 8:00 AM (Eastern Time, US),Recycled PlasticDuring production, the "wash water" used to clean raw materials may contain various hazardous chemicals, warranting attention from both industry and regulatory authorities to ensure the safety of recycled plastic products and environmental sustainability.

As the global plastic pollution crisis intensifies, recycling is regarded as a critical solution to reducing plastic waste. The U.S. Environmental Protection Agency (EPA) has set a target of increasing the national plastic recycling rate to 50% by 2030, requiring an 8- to 10-fold expansion of current recycling capacity. However, studies indicate that achieving this goal demands not only increasing the volume of recycled plastics but also paying attention toRecycled plasticPotential safety risks in the production process.

Post-consumption plastic packaging is typically contaminated with a variety of pollutants, including paper scraps, food residues, adhesives, metal fragments, glass shards, printing inks, and various chemical additives such as plasticizers, antioxidants, colorants, heat stabilizers, lubricants, and heavy metals. If not effectively removed, these substances mayRecycled plasticThe migration to the final product during the production process affects the safety of the final product.

The study, led by Iowa State University, focused on analyzing the composition of wash water used to clean post-consumer polypropylene (PP) plastics. Polypropylene is widely used in food packaging, take-out containers, stackable containers, and other everyday items.Recycled plasticThe cleaning process in production is particularly critical. A study funded by the IAFNS Committee on Food Packaging Safety and Sustainable Development aims to evaluate the impact of different cleaning technologies on contaminant control and to explore safer processing solutions.

Research indicates that there is still a lack of international or national quality regulations for the water used in post-consumer plastic cleaning. During the mechanical recycling process, to remove surface stains and residues, cold or hot water is often used in conjunction with surfactants and corrosive chemicals for rinsing. While high-temperature water can more effectively remove stubborn dirt, it can also introduce oils, suspended particles, and organic pollutants into the washing water. If not properly managed, these pollutants may threaten public health and the ecological environment through water discharge or secondary contact.

The test results showed that in the washing water of polypropylene, DCHP (di(cyclohexyl) phthalate) and DEHP (bis(2-ethylhexyl) phthalate) were the highest content hazardous pollutants, while other phthalates and bisphenol substances were not detected. Meanwhile, with the increase of processing intensity, the concentration of surfactants showed significant changes, indicating the need for continuous monitoring of cleaning efficiency and prevention of potential health and environmental risks.

Researchers recommend using surfactant-containing corrosion cleaning or ultrasonic-assisted cleaning to significantly improve plastic cleaning efficiency; however, these methods also increase the degree of washing water contamination, necessitating the implementation of highly efficient wastewater treatment measures. Furthermore, this study provides foundational data for developing a future risk assessment framework for washing water, emphasizing the need to consider the entire process.Recycled plasticStart from the production chain, formulate a unified standard.

Experts point out that ensuring contaminants in recycled feedstock are thoroughly removed is essential for producing safe, high-quality products.Recycled plasticThe crux of packaging. Since some pollutants can transfer to the washing water, the industry should actively develop treatment technologies and promote policy-level establishment of clear limits on washing water quality to achieve this.Recycled PlasticThe long-term sustainable development of the system.