As the national capital reels under heavy pollution, demand for masks are going up in markets, especially for the N95 variant, which is generally recommended by doctors.
On Wednesday, the city remained blanketed by a thick haze with its air quality dropping further, largely due to the heavy load of smoke from stubble burning in neighbouring Haryana and Punjab, according to government agencies.
Twenty-seven of the 37 air quality monitoring stations across Delhi recorded the air quality index in the "severe" category.
The demand for masks has gone up, Mohammad Monish, owner of Neelkanth Chemists in east Delhi's Dilshad Garden, said.
"People have been asking mostly for the N95 face masks as suggested by experts," he said.
Proprietors at Aggarwal Medicos in Greater Kailash said, most of the people are purchasing N95 masks, cost of which ranges from Rs 200 to Rs 2000, depending on company to company.
Dr Vijay Dutt of internal medicine at the Indian Spinal Injuries Centre said, post Diwali, Delhi's air becomes more hazardous to inhale and the pollutants will harm everyone, but most vulnerable are asthma patients, pregnant women, the elderly and children.
"Some of the precautionary methods would be to wear a mask while going outside and the right mask needs to be worn. I would advice to avoid surgical and comfort masks as it don't allow proper respiratory protection. A respirator that is rated N95/N99/FFP3 or is 'NIOSH approved' filters out more and should be used," he said.
The city's pollution levels peaked at 2 am on Wednesday, touching the 423 mark. The overall AQI oscillated between 410 and 420 during the day, according to data from the Central Pollution Control Board.
Chief Minister Arvind Kejriwal said the Delhi government will start distributing masks among school students from Friday following a spike in the pollution level.
Fifty lakh N95 masks would be given to students in both government and private schools in Delhi, he said on Wednesday.
Also, schools in Delhi-NCR have advised parents to send their children for classes wearing masks and shift outdoor activities indoors to deal with the pollution.
Besides, owners of electronics equipment stores in Dilshad Garden, said many customers are also asking for air purifiers for their homes and offices.