Taiwan's medical equipment factories go through some of the strictest certification requirements in the world - including ISO, CE, ASTM, and the FDA. Some Taiwan factories have been focused on producing face masks and other medical products for over 70 years.
We used to be the number one exporter of medical products before China took that position in the 80s, competing mainly on lower cost of raw materials and labor. Today, Taiwan still maintains its position as the #2 maker of face masks in the world with many of its own patented textile technologies, from spunbond fabric to the meltblown that is the critical layer in every single 3-ply mask.
For instance, Taiwanese meltblown can retain 99% static efficacy even after 5 years, elongating not only the lifespan of the product but also ensure that protection remains constant. Products manufactured elsewhere often lose efficacy after just one year, and in some egregious cases, 2 weeks. In addition, Taiwan is also capable of manufacturing every part of the mask, further ensuring control of quality and a steady supply of materials.
Since February 2020, Taiwan has donated over 15 million masks to countries all over the world in response to the shortage for PPE. In July 2020, Finland finally cemented Taiwan's top spot in high quality face masks by achieving an astonishing filtration rating of 99.7% in their national laboratories. This level of filtration is higher than any other similar products manufactured by China, Vietnam, and other countries. (source)