For example, for chain transfer agent, initiator and reaction promoter combinations, forms such as {HEAD ~ sodium hydrogen sulfite /hydrogen peroxide} , sodium hydrogen sulfite /sodium persulfate , {TAIL ~ sodium hydrogen sulfite} /Fe, sodium hydrogen sulfite /hydrogen peroxide /Fe, sodium hydrogen sulfite /sodium persulfate /Fe, sodium hydrogen sulfite /sodium persulfate /hydrogen peroxide , and sodium hydrogen sulfite /oxygen/Fe are favorable 
For example , for chain transfer agent , initiator and reaction promoter combinations , forms such as { HEAD ~ sodium hydrogen sulfite /hydrogen peroxide } , sodium hydrogen sulfite /sodium persulfate , { TAIL ~ sodium hydrogen sulfite } /Fe , sodium hydrogen sulfite /hydrogen peroxide /Fe , sodium hydrogen sulfite /sodium persulfate /Fe , sodium hydrogen sulfite /sodium persulfate /hydrogen peroxide , and sodium hydrogen sulfite /oxygen / Fe are favorable
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH