The existence and nature of respiratory hazards

The composition of normal air includes 78% nitrogen, 21% oxygen, and a small amount of inert gas. When there is a harmful substance in the air, that is, any gaseous or granular substance that does not exist in normal air and has a concentration that exceeds the range specified by the National Occupational Hygiene Standards, it constitutes a respiratory hazard.

There are 5 forms of harmful substances in the air. They are:

1. Dust: The tiny solid particles suspended in the air are generally produced by the solid material broken by mechanical forces. For example, if ore is cut, such as coal dust, whisk, cement dust, etc.; asbestos dust is fibrous, but also belongs to dust. High temperature gloves

2. Smoke: Tiny solid particles suspended in air, resulting from the condensation of gases or vapors, usually have a smaller particle size than dust. Welding smoke is a typical example. It consists of metal oxides.

3. Fog: Small liquid particles suspended in the air, usually produced by spraying liquids, such as spray paint varnish.

4. Gases: Harmful substances in the form of gases at normal temperature and pressure, such as chlorine, carbon monoxide, hydrogen sulfide, and sulfur dioxide. Acid and alkali resistant gloves

5. Vapors: gases produced by evaporation of substances present in liquid or solid state at normal temperature and pressure, such as benzene, toluene, gasoline, and mercury vapors. Labor Insurance Supplies

Dust, smoke, and fog are collectively referred to as particles, or aerosols. Particles are usually odorless, the smaller the particles, the longer the suspension in the air, the greater the likelihood of being inhaled. Our airways have a self-defense mechanism for whether or not utility bills can be used to remove large particles, but tiny particles below 10 to 7 microns can break through the defenses into the deep respiratory tract, which is alveoli, and stay there, after years of accumulation, gradually Health hazards that cause all kinds of pneumoconiosis dust are very comfortable is this kind of dust, called respiratory dust. As the utility bill is visible to the naked eye is more than 10 microns, so Hudu is very comfortable to absorb dust is not visible. So why can we see welding smoke? That's because the local concentration is too high. When it spreads into a large space, it is invisible to the naked eye.

China Labor Insurance Network