Cars are often in tunnels, could be dangerous there? For comparison purposes, note that indoors CO2 will go from 400 -> 1000ppm+ rather quickly if its not vent

Cars are often in tunnels, could be dangerous there? For comparison purposes, note that indoors CO2 will go from 400 -> 1000ppm+ rather quickly if its not ventilated According to this source [1], CO2 went from 400 -> 3000ppm inside a car cabin in 30mins, which is ~86ppm/min just from breathing. I could easily imagine a gas inside a car leaking at a faster rate and reaching 700ppm in a very short period of time. [1]: https://www.co2meter.com/blogs/news/high-carbon-dioxide-co2-levels-indoors https://www.co2meter.com/blogs/news/high-carbon-dioxide-co2-...