Regardless of the process used to produce it, it must be defluorinated. The existence of solids indicates the incomplete digestion of rock by sulfuric acid or it shows that the producer did not go to the trouble to separate the solids from the acid. Also, as previously note, the acid must be defluorinated.
Phosphoric acid is very reactive acid.
Tank cars and tank trucks must be grounded before contact is made between the tank and the unloading equipment. Contact of the acid with metal liberates hydrogen, and explosive gas. Contact with the skin can cause chemical burns and damage to tissue. Under fire conditions, toxic vapors may form. Protective clothing and eye protection must be worn, and safe handling procedures followed when handling, using or storing phosphoric acid.