Persons entering areas and buildings subject to flooding face a variety of potential hazards, including but not limited to electrical hazards, structural hazards, displaced wildlife, exposure to chemicals and sewage in contaminated floodwater, and mold growth from water-impacted building materials. First and foremost, life safety issues, such as avoiding electrical shock and carbon monoxide poisoning, must be considered before any clean-up or response is initiated.

Before You Begin - The Incident Command System (ICS)

When there is an incident, such as a natural or man-made disaster, an Incident Command System (ICS) is typically established for response command, control, and coordination. ICS is a nationally-recognized framework under which all involved or interested entities and stakeholders (whether federal, tribal, state, local, or private) operate. It establishes one command structure with known and scheduled deliverables and uses standardized terminology.

Because the ICS is mandated for disaster response agencies such as the Federal Emergency Management Agency (FEMA), U.S. Environmental Protection Agency (EPA), and U.S. Coast Guard (USCG), it is important to note that the ICS may be in place and active in your area, even if the response phase is over and the recovery phase has begun. It is often best to start by performing a search on an internet search browser for "ICS Liaison" and the name of the event or location to see if the ICS has a website set up. If this does not yield an established website for your response, go to www.disasterassistance.gov and enter the address of the affected property.

If the area inclusive of the address entered has been declared for individual assistance, you can try "Find Assistance" and then "Apply Online" if applicable. If you do not have access to the internet, you may contact FEMA directly:

  • Call 7 a.m. to 11 p.m. ET, 7 days a week:
    • 1-800-621-FEMA (1-800-621-3362)
    • TTY 1-800-462-7585
    • 711 or VRS 1-800-621-3362
    • You can also email: FEMA-ContactUs@fema.dhs.gov (get a response in 1 to 2 business days) or write to:

FEMA
P.O. Box 10055
Hyattsville, MD 20782-8055

This step is important because the incident command may be able to provide invaluable data about what is happening as well as additional resources before you attempt to return to or enter your home or business.

Before Entering Your Home

Hazards in and around flooded buildings include risk of structural collapse, electrical hazards, sewage contamination, trip and fall injuries, fire and explosion hazards where natural gas or bottled gas are present, and loose or broken gas piping and gas leaks. Guidance for preparing to enter your home may be found at these websites:

Electrical Hazards

Flooding caused by hurricanes and storms can create significant electrical safety hazards. Floodwater contaminants can create serious fire hazards if electrical wiring and equipment have been submerged in water. Even with professional cleaning and drying, sediments and toxins are difficult to remove.

After a flood, dealing with the hazards is not a do-it-yourself project. Before energizing a circuit, you should have a qualified electrician or electrical inspector check it thoroughly to assess the extent of the damage, and only then proceed with repair or replacement. Underwriters Laboratories (UL) (offers these important safety tips:

  • Do not flip on a switch or plug in an appliance until an electrician confirms it is safe.
  • Do not touch a circuit breaker or replace a fuse with wet hands or while standing on a wet surface. Use a dry plastic or rubber-insulated tool to reset breakers, and use only one hand.
  • Do not allow power cord connections to become wet. Do not remove or bypass the ground pin on a three-prong plug.
  • Use portable ground-fault circuit-interrupters (GFCIs) to help prevent electrical shock injuries.
  • If electrical devices such as circuit breakers, receptacles, and switches have been submerged, discard and replace them.
  • When using a wet-dry vacuum cleaner or pressure washer, follow the manufacturer’s instructions to avoid electrical shock.

Often after a flood there is a question as to whether you should replace or recondition electrical equipment. Corrosion and insulation damage can occur when water and silt get inside electrical products. Water can also damage motors in electrical appliances. Therefore, you should be prepared to replace:

  • Circuit breakers and fuses
  • All electrical wiring systems
  • Light switches, thermostats, outlets, light fixtures, electric heaters, and ceiling fans
  • Furnace burner and blower motors, ignition transformers, elements, and relays
  • Hot water heaters
  • Washing machines, furnaces, heat pumps, refrigerators, and similar appliances.
  • Electronic equipment, including computers and home entertainment systems.
  • Air conditioners
  • Non-submersible pumps
  • Boilers

The writers at Popular Mechanics magazine caution against going into a flooded basement until the utility department, fire department, or a licensed electrician has removed the home’s electrical meter from its socket. Removing the meter from the socket is the only way the house can be completely disconnected from the grid.

Even if you have no power, you can still be electrocuted in a flooded basement if someone is running a generator nearby and back-feeding electricity into a storm-damaged grid. Even after the building is fully disconnected from the grid, never go into a flooded building alone. Put on chest waders and bring a bright flashlight that clips to your hat or your waders so you do not have to carry it. Have someone standing by in case you need help.

Additional precautions are offered by Electrical Safety Authority:

  • Move dangerous chemicals such as weed killers, insecticides, and corrosives to dry areas to reduce the chance of contaminating electrical equipment.
  • Shut off all electrical power and the gas supply valve to any gas-fired appliance prior to flooding, if possible. Shut off the electrical supply to all oil-fired equipment.

More information on electrical hazards and electrical appliances and equipment can be found at:

Hazardous Materials and Conditions

Hazardous materials and conditions may be present as a result of damaged building materials containing lead or asbestos, sewage-contaminated items, or hazardous materials such as chemicals or cleaning products present in floodwater. Heat stress and cold stress may be present when working long hours. Fire and carbon monoxide poisoning from combustion sources may also be a concern.

Here are some useful resources to recognize and address these kinds of hazards:

Mold and Other Microbial Growth

If possible, wet building materials and contents should be dried as soon as possible (preferably within 24-48 hours) to prevent mold growth. When a flood event occurs as part of a widespread natural disaster, the electrical power service and professional services necessary to actually begin cleaning, disinfecting and drying of building materials are not normally available in the 24-48 hours following the event, and can take up to several weeks before roads are cleared, power is on and equipment and people are available to clean, disinfect, and dry the building. This means that mold and bacterial contamination should be expected after a significant flooding event. Guidance for small-scale cleanup can be found as follows:

  • If the overall amount of impacted materials is less than about 10 square feet, the CDC has guidance for homeowners and renters for entry and clean-up.
  • The EPA has guidance on how to address mold clean-up on your own.

Be sure to read the label and follow all manufacturer’s recommendations when using any chemical disinfectant for cleaning purposes. Because of the significant risk for adverse respiratory effects and the caustic nature of bleach, the use of bleach for cleaning purposes must be approached with caution.FEMA notes in its guidance on cleaning flooded buildings found that while bleach is convenient as a cleaner and stain remover for hard, non-porous items, it has distinct drawbacks when cleaning water-damaged materials. Many types of bleach are not EPA-registered as a disinfectant. Furthermore, bleach’s effectiveness in killing bacteria and mold is significantly reduced when it comes in contact with residual dirt, which is often present after a disaster. Also, if bleach water comes into contact with electrical components and other metal parts of mechanical systems it can cause corrosion. Bleach water can also compromise the effectiveness of termite treatments in the soil surrounding the building.

If significant mold or other sewage contamination has occurred, however, it is recommended that business owners and homeowners seek professional guidance before attempting to clean large amounts of contaminated materials. Industrial hygienists and other safety and health professionals can anticipate health and safety concerns and design solutions to prevent exposures using guidelines established by government agencies and institutions such as the Institute of Inspection, Cleaning and Restoration Certification.

Be cautious when considering hiring contractors to perform mold remediation. Some states, such as Florida, Texas, Louisiana, New Hampshire, New York and others require licensure for mold assessors and mold remediators, so be sure to check your state’s requirements.

Guidelines for evaluating contractors can be found at the following sources:

Other sources of guidance related to mold response are:

  • American Industrial Hygiene Association

Technical guidance for the industrial hygienist includes:

Food and Drinking Water

Guidelines for food and drinking water are available on these websites:

Personal Protective Equipment

If you choose to perform clean-up activities on your own, be sure to wear appropriate personal protective equipment to protect yourself during the process. Guidelines for protective equipment may be found at the following sites:

Caution should be taken when wearing a respirator to perform any cleanup activity. While EPA and CDC both recommend the use of a National Institute for Occupational Safety and Health (NIOSH) certified N-95 respirator over a dust mask or surgical mask for mold cleanup, it is important to understand the limitations and additional risk of wearing a respirator. N95 respirators will not protect against chemicals or gases in the air, such as carbon monoxide or airborne vapors of chemical disinfectants. The respirator will not work if air leaks around the sides, so the manufacturer provides fitting procedures that must be followed and the correct size of respirator must be worn. Beards or other facial hair may prevent the respirator from fitting properly. People with chronic heart or lung conditions (such as congestive heart disease, asthma, and other conditions) should consult their health care provider before using a respirator. OSHA requires that employers provide training, fitting of the correct respirator size and testing of that fit, and a medical evaluation prior to fitting and use of the respirator. For additional information, be sure to thoroughly read the information presented in these resources before purchasing or using a respirator:

General Response Resources

General disaster relief assistance information is available on these websites: