Solidification binds the waste in a solid block of
material and traps it in place. This block is also less
permeable to water than the waste. Stabilization
causes a chemical reaction that makes contaminants
less likely to be leached into the environment. They are
often used together to prevent people and wildlife from
being exposed to contaminants, particularly metals
and radioactive contaminants. However, certain types
of organic contaminants, such as PCBs and pesticides,
can also be solidified.