How to Use Borates to Kill Mold

Mold can damage your home and belongings and even your health, especially if you suffer from allergies or asthma. A thorough cleaning that includes a borate-based detergent can eliminate mold on surfaces and keep it from growing back. Borate is a colorless and odorless material made from the element boron. It is non-toxic to humans but toxic to mold.

  1. Put on the goggles, gloves and mask. If you are cleaning a large or very contaminated area, consider wearing a particle mask that carries Occupational Safety and Health Administration (OSHA) approval.

  2. Remove any furnishings from the contaminated room. Vacuum the room to pick up loose mold spores. Throw out the vacuum bag.

  3. Cover vents and openings with plastic sheeting or drop cloths to seal off the area so that loose mold spores cannot spread to other areas. Open a window for ventilation.

  4. Scrub the moldy surface with a mild liquid detergent dissolved in warm water. Use enough detergent to make a sudsy solution. Rinse and allow the surface to dry. Discard the solution.

  5. Mix one cup of borate-based detergent with one gallon of water and scrub the surface again. Scrub hard with a clean, sturdy brush until the area appears mold-free.

  6. Wipe up any drips or mold dust. Do not rinse the area; the borate needs to stay behind to kill any remaining mold. Dispose of the solution and cleaning materials.

  7. Allow the cleaned area to dry before painting or refinishing.


  • Never paint over mold. It will continue to grow and cause the paint to peel.
Continue Reading