SDS for Phos-Chek (there are a few different Phos-Chek's) https://www.fs.usda.gov/rm/fire/wfcs/products/msds/retard/phoschek/SDS_PC_LC95A-R.pdf https://www.fs.

SDS for Phos-Chek (there are a few different Phos-Chek's) https://www.fs.usda.gov/rm/fire/wfcs/products/msds/retard/phoschek/SDS_PC_LC95A-R.pdf https://www.fs.usda.gov/rm/fire/wfcs/products/msds/retard/ph... I assume iron oxide is the red. I wondered if the red dye I used for herbicides was the same, it's not, it's Rhodamine B from the SDS. It also makes poisoning far easier once I started using it.