(The Gist of Science Reporter) How Safe is Your Tea in a Paper Cup?

(GIST OF SCIENCE REPORTER) How Safe is Your Tea in a Paper Cup?

[February-2021]

How Safe is Your Tea in a Paper Cup?

Recent research by IIT Kharagpur has confirmed the contamination of the hot liquid served in paper cups due to the degradation of microplastics and other hazardous components from the lining material of the cup.
Paper cups are usually lined by a thin layer of hydrophobic film which is made of mostly plastic (polyethylene) and sometimes co-polymers to hold the liquid in the paper cup. Within 15 minutes this microplastic layer degrades as a reaction to hot water, says the first of its kind study conducted in India.
The paper entitled ‘Microplastics and other harmful substances released from disposable paper cups into hot water’ has been published in the Journal of Hazardous Materials recently.
According to our study, 25,000 micron-sized (10 µm to 1000 µm) microplastic particles are released into 100 mL of hot liquid (85 – 90 °C) residing in the paper cups for 15 minutes. Thus, an average person drinking 3 regular cups of tea or coffee daily, in a paper cup, would be ingesting 75,000 tiny microplastic particles which are invisible to the human eyes.
The researchers followed two different procedures – in the first process, hot ultrapure (MilliQ) water (85–90 °C; pH~6.9) was poured into the disposable paper cups, and it was allowed to sit for 15 mins. The homogeneously mixed water was then analyzed for the presence of microplastics as well as additional ions that may have leached into the liquid from the paper cups. In the second process, paper cups were initially dipped in lukewarm (30–40 °C) MilliQ water (pH~6.9).
Thereafter the hydrophobic film was carefully separated from the paper layer and exposed to hot MilliQ water (85–90 °C; pH~6.9) for 15 mins. and Changes in the physical, chemical, and mechanical properties of the plastic films were examined before and after exposure to hot water.