What are the two categories of respirators?

The correct choice identifies the two main categories of respirators as Air Purifying and Air Supplied Respirators. Air Purifying Respirators are designed to filter out harmful particles, gases, or vapors from the air before you inhale them. They rely on external air that is passed through filters to clean it, which is essential for protecting workers in environments where contaminants are present. On the other hand, Air Supplied Respirators provide clean, breathable air from a compressed air tank or a central source, ensuring that the user is not exposed to any contaminated air at all. This type of respirator is crucial in scenarios where the air quality is dangerous or unknown.

Understanding these categories is vital for choosing the right respirator based on specific work conditions and the type of exposure risks. While other choices may include valid types of respirators or configurations, they do not encompass the primary functional categories recognized in respirator classifications.