s a very common chemistry trick for making the fake blood. The gradients you need are:1. 2.5g Potassium thiocyanate + 50ml water 2. 2.5g Ferric chloride (Iron(III) chloride) + 50ml waterPotassium Thiocyanate is toxic.however, different from potassium cyanide, which is highly toxic, toxicity of potassium thiocyanate is much weaker, so you may see this chemistry trick in some kids science projectFerric chloride is corrosive if the concentration is high. But the dilute solution( solution required in this experiment) is safe to touch with hands