The present invention is directed to a cross-linked scale control agent particle comprising: a scale control agent and a cross-linker. The scale control agent is cross-linked by the cross-linker. The present invention is also directed to a cross-linked organic-based crystalline inhibitor particle comprising: an organic-based crystalline inhibitor and a cross-linker. The organic-based crystalline inhibitor is cross-linked by the cross-linker. The present invention is also directed to the use of cross-linkers which can also act as benefit agents and to the use of capping and extension agents which act as further benefit agents. The present invention is further directed to a particle comprising more than one cross-linked active agents; the active agent may be a combination of a scale control agent and an organic-based crystalline inhibitor. The present invention is also directed to a method for producing the particles according to the present invention and methods for performing a mechanical fracturing operation, for reducing scale build up in an oil well and a cooling tower using the particles according to the present invention.