The main purpose of filters or cartridges in air purifying respirators is to:

The main purpose of filters or cartridges in air purifying respirators is to remove harmful particles from the air that a person breathes in. These filters are designed to capture specific contaminants, such as dust, smoke, fumes, and biological agents, ensuring that the air being inhaled is safer and free from pollutants. This function is crucial in various settings, particularly in industrial environments or healthcare settings, where exposure to harmful substances can pose serious health risks.

While providing breathable air sounds vital, it is the filters that make the air breathable by cleaning it of dangerous particles. The maintenance of temperature and enhancement of comfort are secondary features that do not directly serve the primary function of the respirator, which is to protect the user by filtering out contaminants from the air. Thus, the correct answer highlights the filters' role in ensuring a safe inhalation environment by effectively removing hazardous materials.