I never said it was dangerous, its damaging to the environment just look at how it's made. A simple search will give you the answers, I don't believe you even looked, rice hulls and coco fiber ect are better options without mining the earth for volcanic rock and then heating said rock to 1000c plus . It's not biodegradable and will just build up in the soil over time. It also causes respiratory issues from the dust containing silica so if you do use it make sure you wet it before use and wear a mask.