🔍 Key Concepts

• Difference between filtering (canister) respirators and supplied‑air (SCBA or fresh‑air hose) systems • Where air supply cylinders or remote hoses are normally located on common shipboard breathing apparatus • How a canister or filter box worn on the chest is typically used in older maritime fire/emergency gear

💭 Think About

• Look closely at where the air is coming from in this illustration: is there a long hose going away from the person, or is the device self‑contained on the body? • Do you see any high‑pressure air cylinders on the back or sides of the person? If not, what does that suggest about the type of breathing protection? • What type of equipment uses a box‑shaped unit on the chest with a short corrugated hose up to the face mask—a remote air line, a pressure cylinder, or a filter/canister?

✅ Before You Answer

• Identify whether there is a remote air hose leading to an external air source (for a fresh‑air hose system). • Check for visible compressed‑air cylinders on the person’s back or belt (for demand‑type or cylinder‑type air masks). • Note that a box canister directly on the chest feeding the mask usually indicates a filtering or canister‑style respirator rather than a supplied‑air system.