GAS detectors vs PPE

Shall we consider gas detector as per PPE?
Guideline says the following:
On the other hand, equipment warning against risks, but which do not have a protective function, such as stand-alone alarm devices e.g., gas detectors or oxygen depletion detectors, are not classed as PPE.
However if these devices are integrated in the PPE then they are to be considered as integral part of the PPE. (Please see also BHSR 2.8 3rd paragraph and BHSR 3.11.2 b)
Link: https://app.box.com/s/smmk5znmwvu3y3ev0bij36bod1ozlfqn
PPE stands for personal protective equipment.
Keep up good work!