When mixed with water, it has a wider spread, causing a bigger area of nerve destruction. Aqueous solution of phenol is more potent than the glycerine solution. The choice of diluent is dependent upon the extent of neurolysis desired. The use of higher concentrations of phenol might predispose to a higher incidence of vascular injury. Shelf life exceeds one year when the solution is refrigerated and not exposed to light.
Phenol turns red on exposure to sunlight and air because of oxidation.
It is metabolized in the liver by conjugation to glucuronides and oxidation to equinol compounds or to carbon dioxide and water. Excretion of metabolites is via the kidneys. Phenol has systemic side effects including central nervous system stimulation, cardiovascular depression, nausea, and vomiting. Systemic doses of more than 5 grams can cause convulsive seizures and central nervous system depression. Doses less than 100 mg are less likely to cause serious side effects.