(1) Production areas: coal mines, non-coal mines, transportation, loading and unloading, building materials, construction, machinery, foundry, medicine, chemicals, breeding, etc. are used in dusty and smog environments.
(2) Daily life: anti-smog, kitchen oil fume (KP type protective mask), second-hand smoke, etc.
(3) The main protection objects: dust, smoke, fog and microbes and other particulate matter.
1. Dust: tiny solid particles suspended in the air, generally produced by the crushing of solid materials by mechanical force.
2. Smoke: tiny solid particles suspended in the air, generally produced by gas or vapor condensation, and the particle size is usually smaller than dust.
3. Fog: tiny droplets in the air in suspension.
4. Microorganisms: tiny organisms in nature that are tiny in shape, simple in structure, cannot be directly observed with the eyes, and must be seen under an optical microscope or an electron microscope.