DOPO is a novel flame retardant intermediate with a PH bond in its structure that reflects the production of many derivatives. Chemical name: 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, white flake or granule, insoluble in water. 
DOPO and its derivatives have higher flame retardant properties due to their different molecular structures than general, unlooped stability and chemical stability. DOPO and its derivatives can be used as reactive and additive flame retardants, synthetic flame retardants, and have long-lasting flame retardant properties, which can be used for flame retardant treatment of polymer materials.