Question: What does a respirator do?

Answer passage (source: CDC):
page_title: Personal Protective Equipment: Questions and Answers
section_headers: Respirators
What is a respirator?
section_content: A respirator is a personal protective device that is worn on the face or head
and covers at least the nose and mouth. A respirator is used to reduce the
wearer’s risk of inhaling hazardous airborne particles (including infectious
agents), gases or vapors. Respirators, including those intended for use in
healthcare settings, are certified by the CDC/NIOSH.

Reviewer feedback on this answer:
Answer is relevant to the question asked by explaining what a respirator is and what it does. Could be improved by explaining differences between types of masks (such as medical grade, personal use, cloth, etc).
This answer tells you exactly what a respirator does and how it protects the wearer. It answers the question thoroughly.

Reviewer ratings:
Acceptable
Excellent

Answer passage (source: CDC):
page_title: Personal Protective Equipment: Questions and Answers
section_headers: Respirators
My N95 respirator has an exhalation valve, is that okay?
section_content: An N95 respirator with an exhalation valve does provide the same level of
protection to the wearer as one that does not have a valve. The presence of an
exhalation valve reduces exhalation resistance, which makes it easier to
breathe (exhale). Some users feel that a respirator with an exhalation valve
keeps the face cooler and reduces moisture build up inside the facepiece.
However, respirators with exhalation valves should not be used in situations
where a sterile field must be maintained (e.g., during an invasive procedure
in an operating or procedure room) because the exhalation valve allows
unfiltered exhaled air to escape into the sterile field.

Reviewer feedback on this answer:
Answer is not relevant to the question asked. The answer explains N95 exhalation valves, but does not explain what a respirator does.
This answer is just about a valve on respirator which doesn't tell you what a respirator does. It doesn't address the question at all.

Reviewer ratings:
Bad
Could be Improved

Answer passage (source: CDC):
page_title: Personal Protective Equipment: Questions and Answers
section_headers: Respirators
How can I tell if a respirator is NIOSH-approved?
section_content: The NIOSH approval number and approval
label
are key to identifying NIOSH-approved respirators. The NIOSH approval label
can be found on or within the packaging of the respirator or sometimes on the
respirator itself. The required labeling of NIOSH-Approved N95 filtering
facepiece respiratorspdf
icon includes the NIOSH name, the approval number, filter
designations, lot number, and model number to be printed on the respirator.
You can verify that your respirator approvals are valid by checking the NIOSH
Certified Equipment List
(CEL).

Reviewer feedback on this answer:
Answer is not relevant to the question asked. The answer explains identifying NIOSH approved respirators, but does not explain what a respirator does.
This answer tells you how to identify what respirator you have as opposed to what the respirators job is.

Reviewer ratings:
Bad
Could be Improved