With face masks becoming mandatory for the next few months amid the ongoing pandemic, a group of scientists at CSIR-National Chemical Laboratory (NCL) has designed face masks which, they say, can filter out up to 99 per cent bacteria. The spun-bound polypropylene medical-grade cloth was tested for bacterial and particulate filter efficiency, ability to breathe when worn, and resistance to liquid splash. Coronavirus spreads through fluids like spit and other droplets, and hence, using a hydrophobic cloth material was key in the making of this mask, said NCL scientists. The prototype masks got tested by the South India Textile Research Association (SITRA) and results for human pathogen Staphylococcus aureus was found to be 99.9 per cent, whereas in case of particulate filter, it stood at 92.63 per cent. The masks have now been certified for use. For Syed Dastager, Mahesh Dharne and Shubhangi Umbarkar, it took just three weeks to develop these masks even as they faced some challenges at the time of procurement of cloth material owing to the lockdown. "We initially tested regular cotton cloth with NCL-patented bacterial nanocellulose solution. Thereafter, we tried the same using a medical-grade cloth, which passed the required tests," said Dharne. On the usability of the masks, he said, " It is not advisable to wash the mask using water but instead, it can be sprayed using alcohol-based solutions. By doing so, one can use a mask for maximum of four days. But, if the user is a healthcare professional, then one time and one-day use is recommended," he added. The masks will be manufactured by Pune-based MSME SETLAB Indiak. During the pilot phase, 5,000 masks will be produced in a day, which is slated to be scaled up to one lakh in the coming days. While the cost of masks depends on the material used, the NCL mask will be sold at affordable rates, like regular cloth-based masks sold in markets these days, said the scientists.
