As the haze disappears from Singapore skies, demand for the N95 masks has followed suit.

Sales have fallen by more than 50 per cent since the three-hour Pollutant Standards Index reading peaked at 401 on June 21, a check with retailers shows.

At Guardian pharmacy, they have tumbled by as much as 90 per cent.

Major chains such as Giant, Cold Storage and Unity say they have enough supplies to meet demand, and Guardian has stopped importing new stock.

The Mustafa Centre pharmacy has also stopped importing masks. At the height of the haze, it sold hundreds of boxes daily. But this has now dropped to between 10 and 15 boxes.

The situation is in stark contrast to that at the height of the haze. Back then, there was a shortage of masks in shops, with queues at many supermarkets and hospital pharmacies.

There were also reports of retailers marking up mask prices, with certain shops selling them for as much as $10 each.

Now, however, the cost of the N95 mask at hospitals and pharmacies has stabilised at around $2.50 apiece.

While the demand for face protection may have abated, air purifiers remain out of stock.

The devices have been unavailable for almost a month at stores such as Gain City and Courts. They said new shipments should arrive by the end of the month.

CHAN HUAN JUN