Solidification refers to a process in which waste materials are bound in a solid mass, often a monolithic block. The waste may or may not react chemically with the agents used to create the solid. Solidification is generally discussed in conjunction with stabilization as a means of reducing the mobility of a pollutant. Actually, stabilization is a broad term which includes solidification, as well as other chemical processes that result in the transformation of a toxic substance to a less or non-toxic form.

Experts often speak of the technologies collectively as solidification and stabilization (S/S) methods. Chemical fixation, where chemical bonding transforms the toxicant to non-toxic form, and encapsulation, in which toxic materials are coated with an additive are processes referred to in discussions of S/S methods. There are currently about 40 different vendors of S/S services in the United...