What are the most common elements in flame retardants?

Bromine, phosphorus, nitrogen and chlorine are commonly used in 

flame retardants. 

 Inorganic compounds are also used in flame retardants, either alone 

or as part of a flame retardant system in conjunction with bromine, 

phosphorus or nitrogen. 

 It is important to note that flame retardants are not readily 

interchangeable. Their areas of application are often specific and 

substitution can be difficult.