Important Information: The Universal 4521 cotton face mask follows the CDC recommendations for facial coverings during day-to-day activities. This mask should not be used in any surgical setting, or anywhere that significant exposure to liquid, bodily, or other hazardous fluids may be expected. This mask should not be used in a clinical setting where the infection risk-level through inhalation exposure is high. This mask is not NIOSH approved N95; it is not for use against silica, asbestos or other harmful substances. Lastly, this mask should not be used in the presence of a high-intensity heat source or flammable gas. There are no warranties, either express or implied, that the Universal 4521 mask prevents infection or the transmission of viruses or diseases.