Organic Peroxides: They are chemicals which are accelerator or heat activated and regulate vinyl ester resins and polyester resins gel and curing. It starts cross binding reactions between reactive monomers like resin and styrene. It is active in at room temperature for setting methyl ethyl, ketone peroxides (MEK-P), polyesters and vinyl esters. It is recommended for curing productions with heat like Tert Butyl Peroxybenzoate (TBPB), pultrusion and hot-press. Benzoyl peroxide (BPO), is active on 80 °C and for hardening systems, it is used with amine accelerator at room temperature. Acetyl acetone peroxide (AAP), is preferable for RTM applications with allocation period from quick pattern.