Filtration

Filtration

Filtration is the process of separating solid particles or harmful substances from an airflow using specialized filter materials. It protects the respiratory system in environments where dust, aerosols, toxins, bacteria, or viruses are present.

Filtration principle

Air filters trap contaminants on the surface or within the structure of the filter medium. There are different types of filters based on the type of contaminants and the field of use—from household to industrial and military applications.

Types of filters

• Particulate filters: Provide protection against dust, smoke, fumes, and other solid or liquid aerosols.
• Combination filters: Combine particle and chemical protection—commonly used in demanding environments (e.g., P3 R).

Filter labeling

Filters must comply with standards (e.g., EN 529) and be labeled by type, protection class, and additional features:

• P1, P2, P3: Particle filter efficiency (low, medium, high).
• R: Suitable for repeated use.
• D: Tested with dolomite dust.
• S: Protection against solid-state aerosols only.

Applications

Filtration is used in the chemical, pharmaceutical, and food industries, as well as in healthcare, military, and emergency response scenarios (e.g., accidents, fires). Protection is provided by masks, respirators, face coverings, or dedicated filtration systems.