A tourist visits Tian'anmen Square in Beijing during the 2017 New Year holiday. (Photo provided to China Daily)
A face mask made by the Japanese company Shigematsu Works Co Ltd has been running out of stock on its online outlets, as many Chinese rush to protect themselves from the smog that has shrouded large swathes of northern China during the entire winter.
Shigematsu, a Tokyo-based manufacturer of personal protective equipment including respirators and face shields, saw surging demand for its face masks online since the end of 2016.
It remains uncertain when the next batch will be ready for sale on its official website and on Amazon.
The sudden popularity of the face mask was largely due to a recent blog describing an experiment comparing pollution protection masks used by Chinese customers, in which the Shigematsu outperformed its competing peers in efficiency and comfort.
Some vendors who sell the Shigematsu masks on Taobao platform are taking advantage of the shortage, pricing a single unit at 8,888 yuan ($1,290), or 200 times its original price.
According to the Shanghai-based seller, because there were very few left in stock and the arrival of the next batch remained uncertain, the price was set so high.
The seller said: "The price is high but no one forces anyone to buy it. The market has the say."
Many of the store's other Japanese-made masks, including those worn indoors like Iris, Pitta, Hakugen and Kowa, have also seen a sales boom, while other online sellers of Japanese face masks were also making a good profit from the smog.
However, experts said that many of the masks are simple surgical-type masks that are designed only to prevent problems such as pollen allergies and are not designed to block the tiny airborne smog particles, which can easily penetrate the mask and enter the lungs and have been reportedly linked to premature deaths.
Surgical face masks have almost no filtration efficiency against pollutants, according to Benjamin Cowling, an associate professor of public health at the University of Hong Kong.
According to Xiao Xiao, a 35-year-old Beijing resident, her family members have tried seven brands of face masks, including 3M, Honeywell and Vogmask. She recently turned to Shigematsu after reading about its outstanding performance.
Xiao said she was willing to spend 50 to 200 yuan for each mask, and does not mind someone profiting, as long as it is effective in blocking out the smog.