Turns out the head of Tesla, SpaceX and PayPal wasn't worried about global chemical warfare – rather, the HEPA filters in the Model X and Model S are designed to protect us against the scourge of air pollution.

After testing the Bioweapon Defense Mode in the not-so-pristine real-world environments of rush-hour freeways and landfills in California and major cities in China, Tesla wanted to test the system in more controlled conditions. A Model X was parked in a climate bubble contaminated with 1,000 µg/m3 of fine, PM2.5 particulate matter. Considering the EPA's rating for "good" air quality is 12 µg/m3, that qualifies as an extreme amount of pollution.

According to the testers, it took under two minutes for the hospital-grade HEPA filtration system to bring pollutant levels down from 1,000 µg/m3 to an undetectable level, allowing them to take their gas masks off and breathe clean air within the cabin. Tesla also says the system even started to clean the air around the car, recording a 40 percent reduction in PM2.5 matter in the bubble once the interior was clear of pollutants.