As a medical device, textiles used in operating theatres have to be conform with the requirements of the European Medical Devices Regulation 2017/745.
They are tested according to EN 13795 -- Surgical drapes, gowns and clean air suits, used as medical devices for patients, clinical staff and equipment.

Infective agents can be transmitted during surgical procedures in operating theatres and other medical settings in several ways. One of the important sources are the noses and mouths of the surgical team. When breathing, speaking, coughing or sneezing, a person releases smaller or larger amounts of droplets of secretions from the mucous membranes in the mouth and nose. Those droplets quickly evaporate and leave nuclei suspended in the air. Nuclei can subsequently spread through the air to a susceptible site such as an open operating wound or sterile equipment, or can be inhaled if dimensions

As part of an ongoing pre-normative project, Centexbel is evaluating the possibility of testing surgical masks for their virus barrier. The aim of this project is to demonstrate the filtration efficiency of different types of masks in relation to very small biological structures, the viruses.