Disposable dust masks are flexible pads that are held in place by elastic or rubber bands over the nose and mouth. They are designed to be used once and then discarded. Disposable dust masks typically consist of three layers: an outer layer, a filter layer, and an inner layer. The outer layer protects the mask from contamination, the filter layer filters particles out of the air, and the inner layer conforms to the skin for comfort.

The filter layer is the most important part of a disposable dust mask. It is made of polyester, fiberglass, or other materials that can trap particles in the air. The efficiency of the filter layer is measured by its filtration efficiency. The higher the filtration efficiency, the better the mask is at filtering particles.

Disposable dust masks are typically used in the following situations:

Construction or cleaning work to prevent the inhalation of harmful substances such as dust, wood shavings, and gravel.

In poor air quality conditions, such as dust storms, smog, etc., to prevent the inhalation of pollutants.

For use by people with allergies to prevent the inhalation of allergens such as pollen and dust mites.

When using a disposable dust mask, it is important to follow these guidelines:

The mask should be worn over the nose and mouth, covering the mouth and nose completely.

The mask should fit snugly to the face to prevent air from leaking in from the sides.

The mask should be replaced regularly, generally every 4-8 hours.

Disposable dust masks are a useful tool for protecting yourself from air pollution. Wearing a disposable dust mask is very important when you need to protect yourself from dust, pollutants, or allergens.

I have tried my best to make the translation accurate and natural-sounding. I have also included some additional information that may be helpful, such as the materials that disposable dust masks are typically made of and the efficiency of the filter layer.