NEW DELHI: Referring to research that claims once 80% of the population wears a mask, the coronavirus outbreak “can be stopped immediately”, office of the principal scientiﬁc adviser (PSA) to the government on Tuesday issued a detailed manual on homemade masks which can be easily produced with household material and can also be reused.“Wearing the masks is specially recommended for people living in densely populated areas across India,” said the office of the PSA, K Vijay Raghavan . Quoting the World Health Organisation (WHO), the manual emphasised that “masks are effective only when used in combination with frequent hand-cleaning with alcohol-based hand rub or soap and water. If you wear a mask, then you must know how to use it and dispose of it properly.”The manual, issued by the PSA office, will help people to make such masks at home with the help of simple household materials such as cotton cloth, scissors and sewing machine.The analysis of the US-based National Center for Biotechnology Information (NCBI) says masks can minimise the risk of the Covid-19 spread. “If 50% of the population were to wear masks, only 50% of the population would be infected by the virus. Once 80% of the population wears a mask, the outbreak can be stopped immediately,” the PSA’s office in its statement said.The analysis further said, “Covid-19 virus spreads easily from person to person contact. Virus carrying droplets dry fast enough to form droplet nuclei and remain airborne eventually landing on different surfaces. The SARS-CoV-2, the virus that causes Covid-19, has been detected in aerosols for up to three hours and on plastic and stainless steel surfaces for up to three days”.The proposed guide is meant to provide a simple outline of best practices to make, use and reuse masks to enable NGOs and individuals to self-create such masks and accelerate widespread adoption of masks across India.Besides, the PSA asked scientific institutions to self assess and prepare their labs for research and testing through the standard and rigorous protocol.The entire response is being monitored by the science and technology empowered committee for Covid-19. The committee, constituted on March 19, is responsible for coordination amongst science agencies, scientists, industries and regulatory bodies.