Eff Wear™ face masks are not intended to act as medical devices or other medical products, and should not be used as a replacement for conventional and approved personal protective equipment, including surgical masks or respirators. No warranties, either express or implied, are hereby given that our products will prevent infection or the transmission of viruses or diseases. The face masks are not a substitute for professional medical advice, diagnosis or treatment. If you have any specific questions about any medical matter, you should always consult a doctor or other healthcare provider.