Taipei, Aug. 13 (CNA) A pharmaceutical association in Taipei said Thursday that people should be on the alert against false labeling of surgical masks sold in some online stores, which are advertising the products as made in Taiwan.

So far this week, more than 140,000 imported face masks with false labeling have been seized by the Customs Administration, according to the Taiwan Pharmaceutical Marketing and Management Association (TPMMA).

The association's president Kao Meng-hsi advised buyers to purchase their surgical masks from reputable physical stores, where the origin of the products can be verified.

It is always safer to buy masks that are properly packaged rather than those sold in transparent plastic bags with no labels, he said.

Offering similar advice, pharmacist Shen Tsai-ying said buyers should look for the CNS Mark on the package, as well as the manufacturer's name and contact information.

The mask boxes should be labeled "CNS14774," which indicates that the product has been approved for medical use, Shen said, adding that not all masks are made to that standard, as some are only for protection against dust and other types of atmospheric pollution.

According to the website of the Bureau of Standards, Metrology and Inspection (BSMI), the CNS Mark indicates "compliance of product quality with national standards and the compliance of manufacturers' quality management systems with the requirements of ISO 9000 series of standards."

The issue of mask quality and origin arose in Taiwan this week after the Customs Administration seized 7,350 imported masks on Monday and another 132,781 the following day, all of which were falsely labeled "Made in Taiwan."

On Wednesday, Taipei customs officers said the masks had been shipped via courier either from China or Hong Kong, with documents falsely listing Taiwan as the origin.

Taiwan's Customs Administration said that since Aug. 1, it has been conducting more rigorous checks for counterfeit masks shipped via the postal system or courier services, as people have been importing cheap surgical masks for resale at higher prices.

Government approval is required for the importation of surgical masks for use in medical facilities or resale, the Customs Administration said, adding that masks made in Taiwan are of a higher quality that those produced in China.

Furthermore, Taiwan prohibits the importation of foreign-made goods that have been falsely labeled to misrepresent the country of manufacture, either through text or representative markings, the Customs Administration said.

The unlimited sale of surgical masks resumed in Taiwan in June, after months of rationing by the government, which was requisitioning the bulk of the domestic supply for medical use amid the COVID-19 pandemic. Taiwan had since increased production to meet local demand and also to supply overseas markets.