Mold & Mildew

Mold and mildew are fungi that grow on, and sometimes within, surfaces. They can cause discoloration and odor problems, deteriorate building materials, and lead to health problems such as asthma episodes and allergic reactions in susceptible individuals.


What are spores?

Spores are the dormant form of mold, they are present everywhere in our environment. Mold develops from spores when humidity rises above 70 percent. Warmer temperatures (above 65 degrees F) also increase mold growth.

Damp basements and closets, or bathrooms with little ventilation are ideal environments for mold and mildew growth.

Mold can ruin organic materials such as photographs, books, and cloth. It can also make permanent stains on plaster and other materials. Mold can produce allergic reactions in persons with respiratory conditions. With certain types of mold, reactions can sometimes be severe.

Reduce humidity and temperature. Open windows and doors if outside humidity is lower. Install and use dehumidifiers, remember to empty them often.

Increase ventilation. Use fans to dry and increase circulation.

Look for signs of mold. Mold can grow and spread quickly. Be aware of potential problem areas and correct them as soon as possible. Dry and brush off objects affected by mold or clean with disinfectant products. You can’t get rid of mold spores, but you can prevent their growth by eliminating or reducing favorable growing conditions.


Cleaning up After Flood & Sewer Backups

Bacteria, fecal material, viruses and other organisms associated with sewer water backups can cause disease. Use the following information to protect your health and prevent disease.


How do sewer backups occur?

  • Flooding of sanitary sewers during heavy rain.
  • Blockage in private sewer line (home, apartment).
  • Blockage in public sanitary sewer line.
  • Plumbing problems, such as gutters/down spouts or sump pumps connected to sanitary sewers.


How do I clean up after floods and sewer backups?

  • Odors from sewage backups are unpleasant but not harmful. Removal and cleanup of sewer water are essential.
  • Wash contaminated surfaces/objects with warm, soapy water and disinfect with a bleach/water solution, one cap of 5.25 percent chlorine bleach per one gallon water.
  • Discard or properly wash and disinfect toys, clothing, and other contaminated objects.
  • Wear rubber boots and gloves during removal/cleanup.


How do I prevent disease during floods and sewer backups?

  • Avoid skin contact with sewer water, especially cuts and sores. Keep them clean and covered.
  • Do not allow children to play in areas contaminated by sewage backup.
  • Do not eat/drink anything exposed to sewer water.
  • Keep contaminated objects, water and hands away from mucous membranes (mouth, eyes and nose).
  • Wash hands frequently, especially after bathroom use, before eating, and immediately following contact with sewer water or contaminated objects/surfaces.


When disinfecting contaminated objects…

  • Read and follow label instructions on bleach.
  • Never mix cleaning products.
  • Do not use ammonia.


Additional cleanup recommendations and precautions

The following guidelines may help prevent the transmission of disease and reduce property loss.



Turn off main power switches. Air out and wipe dry all appliances and electrical outlets exposed to water before use. If you have fuel oil or gas systems, be sure tanks are secure and all lines are free from breaks.


Carpets and rugs

You can save carpet replacement costs by keeping carpets in place and cleaning with a mild detergent; carpets cleaned after removal nearly always shrink beyond recovery. Carpets and rugs with severe exposure to water must be removed to thoroughly clean. Remove silt accumulated on carpet liner. Generally, the carpet liner must be discarded because it cannot be cleaned adequately. If you prefer, call a reputable carpet cleaner.


Floors, drapes and furniture

Scrub and wash all objects in your home, including clothes, exposed to flood waters. If available, use the city water supply; it is chlorinated adequately to provide mild disinfection. Use cold tap water with soap – boiling the water will eliminate the chlorine content. Floors and other flood contacted surfaces should be disinfected with a chlorine solution made from household bleach. Prepare the solution by adding one heaping tablespoon of bleach (5.25%) to every four gallons of water. Take good curtains and draperies to a reputable dry cleaner.



Open all windows for drying and ventilation. Use electric fans.


Food and water safety

Discard food exposed to flood waters. If refrigerators and/or freezers have taken in flood waters, discard food stored there. If no flood water entered these appliances but power was lost long enough for foods to thaw, discard all partially thawed foods unless prepared immediately. Discard milk, cheeses and other foods prone to spoilage. Completely thawed meats and vegetables should be discarded without question. Discard all bulging or leaking canned food.

Keep flood waters away from mouth, nose, eyes and skin if possible. Flood waters can carry microorganisms and other contaminants. Keep children from playing in water. Wash and sanitize all contaminated utensils and cookware.



For more information please call Hamilton County Public Health at 513-946-7800.


Download a printable version of this fact sheet here.


250 William Howard Taft Road
2nd Floor, Cincinnati, OH 45219
Phone 513.946.7800 Fax 513.946.7890