A Romanian university has published the results of a study on how safe it is to eat snow.

Istvan Mathe, a professor at the Sapientia Hungarian University of Transylvania, told The Associated Press on Thursday that the 2017 experiment showed it was safe to eat snow which was a half-day old, and safer to eat it in the colder months. By two days old, it’s not safe to eat.

Conducting the experiment, scientists collected snow from a park and from a roundabout in Miercurea Ciuc, central Romania, in January and February and placed it in hermetically-sealed sterile containers. They then tried to grow bacteria and mold in them. The study took place in temperatures ranging from -1.1 C to -17.4 C (30 F to 0.7 F) in the city, one of the coldest in Romania.

After one day, there were five bacteria per millimeter in January, while in February the number quadrupled.

“Very fresh snow has very little bacteria,” he said by phone. “After two days, however, there are dozens of bacteria.” He said the microorganisms increase because of impurities in the air.

Mathe said he first had the idea when he saw his children eating snow.

“I am not recommending anyone eats snow, just saying you won’t get ill if you eat a bit.”

The experiment was the first of its kind in Romania.

(AP)