CPR Masks & Aids
The barrier exists as much for willingness as for hygiene, since hesitation costs more than anything else in the first minutes. A one-way valve lets air pass to the casualty and blocks return flow. Keyring pouches put one on every set of keys; a pocket mask with an oxygen port suits a trained responder or a first aid room. Check the valve is intact. See CPR training, first aid kits and kit refills.
