0 a device worn over the nose and mouth to prevent you from breathing in harmful substances, such as bacteria or pollution, or from breathing bacteria or viruses onto anyone else:
Workers wearing white protective suits and face masks unloaded the lead-contaminated clay.
Do face masks offer any protection against the virus?
This face mask design and use have previously been described in detail3,10.
Delivery via a laryngeal mask has been introduced as an alternative to the face mask or tracheal intubation for maintenance of the airway.
Briefly, the animal was fitted with a bias flow face mask, and room air was drawn through side ports at a rate of at least 6000 l min21 during exercise.
