Question

fibers
vapors
types
some types of respiratory protection:
disposable masks
half face masks
full face masks
which respiratory protection is best, depends on:
composition of the air
which substances are present in the air, and what are their health hazards.
limit air concentration
the amount of dust particles permitted. this is regulated by the government.
workplace conditions
e.g.: varying temperatures, ventilation, or lack of oxygen.
exposure time
filters become saturated after a while; substances are let through when this is the case.
note:
correct fit and regular maintenance are prerequisites for safe use.
filters have a limited service life.
1
which harmful substances can be present in the air?
microscopic dust particles.
oxygen.
gases
fibers

Explanation:

Oxygen is not a harmful substance in normal circumstances; it is essential for life. Microscopic dust particles, gases, and fibers can be harmful in the air as they can cause respiratory - related problems or other health issues.

Answer:

Microscopic dust particles, Gases, Fibers