Question: When they refer to respirators, what are they referring to?

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:
This answers the question directly. The answer provides definition and explanation of a device called respirator.
This gives a basic explanation of what a respirator is, but there are different types of respirators that are used in different situations, and this question doesn't address those types.

Reviewer ratings:
Excellent
Acceptable

Answer passage (source: CDC):
page_title: Personal Protective Equipment: Questions and Answers
section_headers: Respirators
What do I do with an expired respirator?
section_content: In times of increased demand and decreased supply, consideration can be made
to use N95 respirators past their intended shelf life. However, the potential
exists that the respirator will not perform to the requirements for which it
was certified. Over time, components such as the strap and nose bridge may
degrade, which can affect the quality of the fit and seal. Prior to use of N95
respirators, the HCP should inspect the respirator and perform a seal check.
Additionally, expired respirators may potentially no longer meet the
certification requirements set by NIOSH. For further guidance, visit Release
of Stockpiled N95 Filtering Facepiece Respirators Beyond the Manufacturer-
Designated Shelf Life: Considerations for the COVID-19
Response .

Reviewer feedback on this answer:
This answer is irrelevant to the question. The question is asking of what device is a respirator and this answer is providing information regarding the usage of N95 respirators past their intended shelf life.
This doesn't answer the question about what a respirator is. It just talks about a particular type of respirator and whether people should consider using it.

Reviewer ratings:
Bad
Bad

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:
This answer just explains how to verify that a respirator is approved, but doesn't answer the question about what a respirator is.
This does not answer the question. This answer provides information of how to identify NIOSH-approved respirators whereas the question is asking about what is meant by respirators.

Reviewer ratings:
Bad
Bad