Flame retardant polyphenylene ether resin compositions are described in which the flame retardant agent is a mixture (by weight) of the following:(a) about 1.5% to about 3.0% of: ##STR1## (b) about 15.0% to about 20.0% of: ##STR2## (c) about 23.0% to about 28.0% of: ##STR3## (d) about 47.0% to about 56.0% of: ##STR4## wherein R.sub.1 and R.sub.2 are each selected from the class consisting of hydrogen, methyl and ethyl, it being understood that when one of R.sub.1 and R.sub.2 is hydrogen the other is ethyl and when one of R.sub.1 and R.sub.2 is methyl the other is methyl, the resulting two methyl groups being in the 2,4-, 2,5-, 2,3-, 3,4- and 3,5-positions, it being further understood that the ethyl groups are almost entirely in the meta (m) and para (p) positions.