resins and alkyd resins. Phthalic anhydride is produced similarly by V2O5-catalysed oxidation of ortho-xylene or naphthalene at 350–400 °C. The equation for the vanadium oxide-catalysed oxidation of o-xylene to phthalic anhydride: C6H4(CH3)2 + 3 O2 → C6H4(CO)2O + 3 H2O The equation for the vanadium oxide-catalysed oxidation of naphthalene to phthalic anhydride: C10H8 + 4½ O2 → C6H4(CO)2O + 2CO2 + 2H2O Phthalic anhydride is a precursor to plasticisers, used for conferring pliability to polymers. A variety of other industrial compounds are produced similarly, including adipic acid, acrylic acid, oxalic acid, and anthraquinone. Other applications Due to its high coefficient of thermal resistance, vanadium(V) oxide finds use as a detector material in bolometers and microbolometer arrays for thermal imaging. It also finds application as an ethanol sensor in ppm levels (up to 0.1 ppm). Vanadium redox batteries are a type of flow battery used for energy storage, including large power facilities such as wind farms. Vanadium oxide is also used as a cathode in lithium ion batteries. Biological activity Vanadium(V) oxide exhibits very modest acute toxicity to humans, with an LD50 of about 470 mg/kg. The greater hazard is with inhalation of the dust, where the LD50 ranges from 4–11 mg/kg for a 14-day exposure. Vanadate (), formed by hydrolysis of V2O5 at high pH, appears to inhibit enzymes that process phosphate (PO43−). However the mode of action remains elusive. References Cited sources Further reading . . External links How Vanadium Oxide Is Used In Energy Storage Vanadium Pentoxide and other Inorganic Vanadium Compounds (Concise International Chemical Assessment Document 29) Vanadium(V) compounds Catalysts Infrared sensor materials IARC Group 2B carcinogens Oxidizing agents Transition metal oxides