What type of respiratory protective system removes carbon dioxide and adds oxygen?

The type of respiratory protective system that removes carbon dioxide and adds oxygen is the closed circuit system. In a closed circuit system, also known as a rebreather, exhaled air is cycled back through the system. This design allows for the removal of carbon dioxide through a scrubber system, while simultaneously replenishing oxygen to ensure that the user has a breathable atmosphere.

This system is particularly beneficial in environments where fresh air supply is limited or in situations requiring prolonged use of the respirator. It provides an efficient way to manage the gases exchanged, thereby maintaining a safe and breathable environment for the user. Understanding this is crucial for firefighters and rescue personnel operating in potentially hazardous atmospheres.

The other options, such as open circuit systems, only allow exhaled air to escape to the external environment, making them less effective for extended use in enclosed spaces where air quality can deteriorate rapidly. Half-mask and full-face respirators are focused primarily on filtering out particulates and harmful gases from the ambient air but do not have the capability to add oxygen or remove carbon dioxide from a closed system effectively.