Teslarati 
Tesla took steps to protect employees at Gigafactory Nevada from exposure to wildfire smoke during working hours, CNBC reported. A devastating wildfire, the Mosquito Fire, destroyed tens of thousands of acres in California. The smoke and ash were blown into nearby towns including Sparks, Nevada.
According to an internal memo shared with CNBC, Tesla told employees at Giga Nevada that the building’s heating, venting and cooling system (HVAC) was set to “recirculation mode to limit the amount of outside air pulled into the factory.”
Tesla previously upgraded the factory’s HVAC filters to Minimum Efficiency Reporting Value (MERV) 13 or higher over the past year. The higher the MERV rating, the more efficiently capturing airborne particles such as dust, pollen, and mold. MERV 13 filters have the ability to filter out 98% of airborne particles including bacteria and virus carriers.
Tesla told employees that the filters were replaced with new ones on a more frequent basis this year and this will continue during the smoky conditions.
CNBC noted that on Thursday and Friday, the overall air quality around Giga Nevada was “very unhealthy” with around 57 micrograms of fine particulate matter per cubic meter of air. When the air quality is at this level, it is advised that everyone should limit outdoor activities and mask up when going outside.
Today and tomorrow, the ranking is “unhealthy for sensitive groups” which indicates that the smoke seems to be clearing out.
