There are several classes of cationic initiators including&colon; Onium salts, organometallic compounds and pyridinium salts. This process requires dispersing medium, monomers, stabilizing agents, and initiators. Not all monomers are susceptible to all types of initiators. Cationic initiators and intermediates characterize cationic ring-opening polymerization (CROP). Water-soluble azo initiators are also available. Other uses include acting as a fuel in pyrotechnic compositions, namely pyrotechnic initiators. The use of radical initiators or other compounds can lead to the opposite product result. There are two types of caspases&colon; initiators and effectors. Some thermite-like mixtures are used as pyrotechnic initiators in fireworks. IWA uses SPNEGO to allow initiators and acceptors to negotiate either Kerberos or NTLMSSP. Special names refer to both iSCSI initiators and targets. Polymers grow off the initiators that are in turn bound to the clay. Some free radicals-derived oxysterols have been suspected of being initiators of atherosclerotic plaques. Styrene will polymerise spontaneously to polystyrene, without the need of external initiators. It also has photo initiators present which enable light curing.