Air purifiers are now sold out at most stores as hazy conditions persist with the latest Pollutant Standards Index (PSI) reaching 299 at 12noon on Thursday.
Major electronics retailers Courts, Best Denki and Harvey Norman told The Straits Times on Thursday afternoon that air purifiers have been sold out since the weekend.
"We are trying to order more, but we don't know when they will come," said a Best Denki spokesman.
Stocks of air purifiers at Air and Odor Management, an indoor air quality company, have also ran out.
Meanwhile, some convenience stores have been spotted marking up prices or controlling the sale of face masks as demand for them surge over the past few days.
One store in Chua Chu Kang Avenue 1 was restricting each customer to only one box of 10 3M N95 face masks, which is sold for $20, while another store was selling the same box for $30.
On Tuesday, Watsons merchandising and marketing director Micheas Chan. said sales for face mask and eye drop rose by 80 per cent and 50 per cent respectively,
This amounted to more than 2,500 face masks and 1,000 boxes of eye drops being sold daily across its stores during this period.
A Guardian spokesman said that as of Tuesday, it had sold seven times more face masks than the previous week. Some 1,000 face masks were sold on Monday alone. She added that it sold 30 per cent to 70 per cent more eye drops, and 30 per cent to 50 per cent more lozenges, on Monday than the day before.