According to Tesla, its air conditioning system is able to protect the car’s occupants from a military-grade bio attack and is more than adequate to fight real-world conditions in polluted cities.
To show that its claims are real, they have conducted tests in a large bubble contaminated with extreme levels of pollution - 83 times over EPA’s good" air quality index limit of 12 µg/m3. After closing the doors for more than two minutes, the HEPA filtration system reduced the hazardous 1,000 µg/m3 polluted air to undetectable levels. This allowed the technicians to remove their gas masks to breathe the clean air inside the car. Furthermore, the system began vacuuming the air outside the car as well, reducing PM2.5’s levels by 40 percent.
Tesla isn't done with its filters though and will continue to further develop the filters, improving their micro-geometry and chemical passivation defenses.