From guano, ie bird droppings, therefore from a bird which is an animal and
not a plant.
If you want untainted phosphate you may have to make it from elemental
phosphorus.

"Christopher Green" wrote in message
om...
(Keith Michaels) wrote in message
...
My can of baking powder lists Calcium Phosphate as an ingredient
and someone told me that it is a slaughterhouse byproduct
derived from animal bones. This is troubling to a vegetarian.
Is it true? Are there animal-free sources for baking powder?

Set your mind at rest. Most calcium phosphate in the food and animal
feed trade is produced from phosphate rock, not bone meal.

--
Chris Green