ROCKFORD, Ill. (WTVO) — It falls from the sky and is just frozen water it its purest form, but is is safe to eat?

Snow, it turns out is not just made of water.

It’s actually made of droplets that contain pieces of dust, tiny bacteria, or other microbes floating in the air.

John Pomeroy, a researcher who studies climate change at the University of Saskatchewan, said snow acts like an atmospheric “scrubbing brush,” according to NPR.

Meteorologist Mary Scarzello Fairbanks, of the National Oceanic and Atmospheric Administration, adds that “In snow, you can find traces of water from rivers, lakes, or oceans around the world,” she told health website, Prevention.

Fairbanks went on to say that snow can contain particles of whatever is happening in the atmosphere, which can include aerosol particles and pollutants.

Other experts warned against eating too much snow in urban areas, as snow can soak up chemicals from gasoline exhaust in the air.

However, Dr. Diane Calello, executive director of New Jersey Poison Information and Education System and associate professor of emergency medicine at Rutgers New Jersey Medical School, said snow is safe to eat in small quantities, adding, “it’s not great to make a meal out of it.”

Calello warned that eating too much snow could result in vomiting or diarrhea, or an infection. But, she said, “that would take a lot of snow.”

But that’s still talking about clean snow, which has just fallen. Scientists warn that you’d definitely want to avoid…yellow snow.