As said several times, these are not masks for medical use. If used in a high risk environment, we recommend to use an additional filter layer. We suggest to use a surgical mask that meets the homologation standards for these environments and place ours on top.
This superposition improves the sealing of disposable masks, increases the filtering level and therefore improves protection.
By wearing our reusable masks most of the time, we reduce the consumption of single use masks as we only utilize them for specific high risk environments.