The kill step is generally the second step of the mold remediation process. Your surfaces have most likely been cleaned with a specialized mold cleaner, and now you want to disinfect those surfaces. There are several chemicals used in the industry, each with their own place and purpose. One of the most common disinfectants is Quaternary Ammonium. Our most popular disinfectant that utilizes this chemical is Fiberlocks Shockwave. It's sold in both a Ready To Use (RTU) version, and a concentrated version. Most contractors purchase the concentrated shockwave, but if this is a small one time use type of job where one gallon is all you need, we recommend going with the Shockwave RTU. We recommend using EPA registered products that are intended for your specific purpose. If you are looking for a botanical solution, we offer both a Shockwave Green with active ingredients of Citric Acid and Ionic Silver, or Concrobium Broad Spectrum Disinfectant that is botanically derived from the tyme plant. We do not recommend the use of bleach for the process of mold remediation. Although a great disinfectant, it is generally considered to not help in the process of killing mold on porous surfaces. Please use all chemicals with caution and with the proper personal protection equipment (PPE).