ELI5: How do odors/smells have physical mass?

I googled "do odors have mass" and the results say they do. How does that work? If someone farts/poops, does it just immediately explode into billions of microscopic particles that engulf the area and get into people's noses? How is that not the most unhealthy and disgusting thing ever, to inhale people's intestinal solids? Same with cooking something? Like, if I had the superpower of being able to see microscopic stuff, I would just see a cloud of beef particles for a square half mile around the burger joint that always smells so good when I drive nearby it?