The makers of Japanese anti-allergy masks are ramping up production, blaming Chinese pollution.

The products, which can block harmful PM 2.5 particulates, which can pass through standard masks, are seeing soaring demand driven by health concerns heightened by air pollution from China.

Kowa Co., Japan’s largest non-industrial mask maker, said it plans to raise output fivehold of its Sanjigen line of masks, which can filter out 99% of particulates as small as 0.1 micron. The company also plans to expand production lines at its Fuji factory in Shizuoka Prefecture and will seek approval to sell the masks in China.

Iris Ohyama Inc. has developed a mask with five unwoven textile layers, compared to three for other masks, to block microparticles. Sales of the product will start on April in the northern Kyushu island, where readings for harmful particulates have already reached hazardous levels.

According to The Nikkei, production of Japan Vilence Co.’s industrial-grade masks, which met the N95 standard of the US National Institute for Occupational Safety and Health, has this year increased by 50%.

Unicharm Corp.’s production of anti-pollution masks has doubled since the beginning of the year and is now considering increasing output.

Authorities issued health warnings last month after the smog from China apparently reached Japan, sending air quality plummeting in some parts of the country.

Japanese officials met with authorities in Beijing to discuss tackling the worsening air pollution in China and its repercussions to its neighbor.