There are a number of different chemical agents that can be used to kill mold and mildew. The easiest method is to use a mixture of bleach and water, possibly with a small amount of detergent added, but there are also many commercial mold and mildew removers.
These chemicals used to kill mold are known as biocides, which means a substance that can kill living organisms. Although using these biocides is often necessary to kill the mold, the U.S. Environmental Protection Agency notes that in most cases it is impossible to completely sterilize the area. This means that mold spores may remain, which could begin growing if they are again exposed to water. Still, using biocides is nonetheless recommended for people who may be allergic to mold or have other health problems.
Even dead mold can lead to allergies and other health problems. For this reason, the EPA notes that it is usually not enough to simply kill the mold, but to remove it and all soiled items and building materials as well.
After scrubbing away and removing all of the mold with the solution of bleach and water, it is then necessary to let any affected items dry out for several days. If new mold reappears within this time, reapply the bleach until it doesn't return.