The demand for face masks has risen due to the spread of the novel coronavirus (COVID-19) pandemic. This method helps avoid wasting disposable medical masks or cloth masks, said Dr Doãn Ngọc Hải.

Hải said the common technologies for disinfection were the use of ultraviolet rays, ozone as a form of oxygen, heat and microwaves.

The institute has tested the standard disinfection of medical masks based on these methods.

In its conclusion, ultraviolet rays could only disinfect the surface but not effectively the middle layer.

Meanwhile, ozone disinfection equipment was quite bulky, and the methods were complicated.  

A used face mask on the street in Hà Nội. 

Using microwaves was the easiest, most feasible and most popular solution, he said.

Hải said people need a common microwave with a default capacity of 800W.

As recommended by experts, the microwave for disinfecting masks should be used separately, not for heating food or other purposes.

People could use disinfectant solution such as 0.9 per cent physiological saline to spray on the mask. The purpose was to moisten the mask.

The mask then was put into the microwave with the antiseptic solution-sprayed side facing up and heated for a minute. The microwave must be in microwave mode, not grill.

People should wait a while for the mask to cool and hold the handle of the mask.

In doing so, each person had a clean mask to use, he said.

Hải noted that the parameters set for microwaves have been thoroughly researched by tests. Therefore, people needed to follow the steps exactly to ensure the disinfection.

Standard, disposable medical masks and cloth masks were the recommended type for this disinfection method. Other types of masks might contain flammable materials when heated in a microwave oven, he said.

The institute has conducted inspections and affirmed the method was guaranteed.

It has renovated a number of microwave ovens and created specialised equipment for sterilising face masks in hospitals and offices. — VNS