http://www.niacet.com/propionates.html Propionates by Niacet, Calcium Propionate & Sodium Propionate, are both FDA approved mold inhibitors providing effective prevention of mycelia, sporangia, and Bacillus mesentericus in bread, cheese and animal feeds. The Calcium Salt is preferred in rolls and bread because it contributes to enrichment by supplying calcium. However, due to the calcium ions interference with the chemical leavening agents, the sodium salt should be used in non-yeast leavened products. en-us