Provides clear metrics:
Specifies only a few challenge gases (typically toluene, SO₂, O₃, NH₃). Does not cover all relevant indoor pollutants (e.g., NO₂, formaldehyde in some versions). iso 10121
: Establishing a simple classification system for end-users. Provides clear metrics: Specifies only a few challenge
| Standard | Scope | Key difference | |----------|-------|----------------| | | Gas-phase media & devices (HVAC) | International, general ventilation | | ASHRAE 145.2 | Gas-phase air cleaners | US-focused, similar but not identical | | ISO 16890 | Particulate filters | Does NOT cover gases | | EN 779 / ISO 16890 | Particulate only | No gas-phase testing | iso 10121
Allows fair comparison between different gas-phase filter technologies (activated carbon, chemisorbents, impregnated media, etc.).