Baking soda

Baking soda, also called sodium bicarbonate (NaHCO3), is a dry, white powdery chemical compound that releases carbon dioxide when combined with certain acids.

In 2268, Leonard McCoy used a container of baking soda as a component of a gas grenade in an attempt to escape the Melkotian illusion. 

Background
Baking soda was used by the visual effects department to create the sprays of snow as Voyager slammed into the planet in.