Crushed red cinder block in chicken coop?

[horsefeathers09]

I have a truck load of red crushed cinder block [looks like sand] and I wanna put it in my coop, anybody know if this would be ok? I use it in my horse pens and it drains great. I know my girls will eat it, so my question is to make sure it won't make them sick. Thanks!

 

[tazcat70]

My father-in-law worked in a concrete factory and he and several others there got cancer. I would do a web search for concrete and find out about eating it.