Precipitated substances in toothpaste, or caused by weather changes.

Yida chewing gum is not a company, it is the brand of the American Wrigley Candy Company: Green Arrow, White Arrow, Yellow Arrow. Yida is a sugar-free chewing gum.

Yida toothpaste is produced by a daily necessities company in Guangzhou. Some time ago, there was a lawsuit due to alleged infringement of the trademark name of Yida chewing gum.