What types of respirators are available today?

The correct choice identifies the primary types of respirators currently used in various environments, specifically focusing on the protection they offer against different airborne contaminants.

Self-Contained Breathing Apparatus (SCBA) provides clean air in hazardous atmospheres, making it essential for firefighting and emergency situations. Particulate respirators are effective for filtering out airborne particles, including dust and aerosols, which is crucial in environments where particulate matter is present. Air-supplied respirators, which deliver a continuous flow of clean air, are particularly useful in spaces where a breathable atmosphere cannot be guaranteed.

While N95 masks and surgical masks also serve respiratory protection roles, they are not classified strictly as respirators in the same way as self-contained and supplied air systems. Carbon filters and half masks have some application but do not encompass the full spectrum of modern respiratory protection. Oxygen tanks and carbon dioxide scrubbers relate more to breathing systems rather than being categorized as respirators.