What does the air line respirator supply air through?

An air line respirator is designed to provide a continuous supply of breathable air to the user through a connected air line. This system allows for a constant flow of clean air, which is essential in environments where the air may be contaminated, inadequate, or otherwise unsafe for breathing. The use of an air line ensures that the respirator delivers fresh air directly from a safe source, whether that source is within a facility or a remote air supply.

In contrast, the other options describe different types of respiratory protection mechanisms. Portable tanks store compressed air but do not provide a continuous supply like an air line. Direct contact with the environment does not ensure a supply of clean air, as it exposes the user to potential hazards. Filtered cartridges can clean the air to some extent, but they rely on the ambient air and can be less effective in highly contaminated situations. Therefore, using an air line is the most reliable method to ensure a safe and consistent supply of air during potentially hazardous work conditions.