I wanted to follow up on my recent post on isocyanates, in which I recommended an airline respirator, and discuss airline respirators in a little more detail. What is an airline respirator? Type C Supplied Air Respirators, more commonly referred to as air-line respirators, are designed to provide long-duration respiratory protection that is independent of the ambient air in the work area. This contrasts with air purifying respirators that use filters or cartridges, which may not offer the level of protection desired or required. The styles available include full face or half mask respirators and hoods that cover the entire head. Each of these may be connected by an air-supply hose to an air source. This flow of breathable air must meet so-called Grade-D standards, which may be provided by either a compressor or air cylinders. When connected to the air source, the respirator delivers a supply of respirable air to the user. The reason to use an airline respirator usually has to do with the chemical involved, or the location of the work. First, some chemicals are either very dangerous (too dangerous for the protection factor of a cartridge respirator), or have no warning properties. That is, you can’t smell or taste them, so won’t know if cartridge is working. Second, some locations, such as confined spaces, may be potentially Immediately Dangerous to Life and Health (IDLH). Choosing the correct airline respirator can separate you from these respiratory dangers. Choose wisely!