South Korean government said Friday it plans to import 53 tons of mask filters through June to keep up the supply of the sanitary item. (Yonhap)
SEOUL, March 23 (Korea Bizwire) — A recent study has revealed that a KF94 mask sterilized with steam can be reused and maintains a 99.9 percent filtering efficiency even after having been sterilized.
The experiment was part of a bid to test the argument that if a used mask is treated with steam for 20 minutes, it can be reused two to three times.
The experiment, conducted by Park Il-young, a professor at the College of Pharmacy at Chungbuk National University, was conducted with two different mask types – KF94, which filter 94 percent of fine particulate matter, and KF80, with an 80 percent filter rating.
The KF94 mask used in the study was a new product, and the KF80 mask was produced in June 2017.
The particle filtering efficiency tests were conducted on untreated masks and dry masks after 20 minutes of steam treatment, with the steam-dry process repeated three more times.
Due to current supply shortages, only two masks of each type were used in the study.
The study was conducted by an organization designated as a testing agency by the Ministry of Food and Drug Safety.
According to the analysis, KF94 masks had a 99.9 percent filtering efficiency rating following each steam-dry cycle.
As such, steaming KF94 masks for 20 minutes and letting them dry has proven to be effective as a disinfecting measure up to three times.
On the other hand, the KF80 masks showed slightly different results. The particle filtering efficiency after the masks were steamed decreased little by little.
In addition, one of the two masks had less than 80 percent efficiency when it was steamed, but it had 90 percent efficiency when it was steam treated three times.
According to the data from the KF80 test, the untreated masks recorded 97.7 percent and 97.8 percent efficiency according to the particle filtering test.
After 20 minutes of steaming and drying, the two masks showed 94.6 percent and 77.3 percent efficiency, respectively.
Finally, after the third cycle, the filtering efficiency of the masks came in at 90.6 percent and 90.1 percent, respectively.
“I think there was a problem in the process of water vapor treatment,” Park said.
“The condensation on the lid falls onto the mask after the steam treatment. In the case of the KF94 masks, the water droplets were not absorbed, but the KF80 masks seem to have absorbed a little bit of water.”
He added, “We have to increase the number of masks to properly identify any outliers, but we are unable to source enough masks for the experiment at the moment.”
D. M. Park (dmpark@koreabizwire.com)
