A technology to produce a phosphorus-based monomer and polymerize it into what will be the first commercial polyphosphonate polymers has been developed by FRX Polymers Inc in USA. These polymers are inherently flame retardant as well as clear and transparent; and can be either homopolymers or copolymers. Copolymers can be produced along with polycarbonates. They can also be blended with styrenics like polycarbonate. FRX polymers are non-halogenated, phosphorous based polymers and have the highest Limiting Oxygen Index (LOI) of all commercial thermoplastics. (LOI is a key metric to determine non-burning characteristics of polymers.) FRX polymers have three distinguishing properties. They have excellent flame retarding properties, they are transparent and also have very high melt flow rate. In addition, due to their polymeric nature, they will not migrate out of the host plastic when used as additives. Tests also show that in certain polymer systems, improved mechanical properties- such as heat distortion temperature, can result. FRX is qualifying PP homopolymers and copolymers for melt blending as polymeric flame-retardant additives in engineering resins and for use as inherently flame-retardant transparent plastics in consumer electronics and other markets. FRX's materials will compete with non-halogenated flame-retardant additives based on phosphorus since they can be used as flame retardant additives in other polymers. These include BPA/DPP (bisphenol A/diphenyl phosphate) and RDP (resorcinol diphenyl phosphate), both of which are liquids and growing rapidly, especially in Europe for TV housings. Flame retardants like these can be used in clear thermoplastics, but they require the addition of PTFE to prevent dripping, which reduces clarity. These polymers had initial patents in 1948 but not commercialized until 2008 because they had low strength, low Tg and poor hydrolytic stability. In 2003, Dr. Freitag began intensive research on them and solved a number of past technical problems, after which Triton set up FRX Polymers to commercialize the technology. FRX now claims 30 patents and patent applications on the monomer, diphenyl-methyl-phosphonate (DPP) and polymers and downstream applications.