Health Safety for Post-Flood Cleanup

The Hawai‘i Department of Health (DOH) is urging residents impacted by recent flooding across the state to take precautions during cleanup and recovery efforts to protect their health and safety.

Floodwater contains hazards. Properly cleaning and drying your home after a flood can make it safe to re-occupy.

As communities begin cleanup and recovery, DOH is providing the following guidance:

Floodwater Safety

• Floodwater contains hazards. Avoid entering or playing in floodwater whenever possible.

If you come into contact with floodwater:

• Wash exposed skin with soap and clean water as soon as possible.
• Use alcohol-based wipes or sanitizer if clean water is unavailable.
• Clean and cover any wounds and seek medical care if needed.
• Wash contaminated clothing in hot water with detergent before reuse.

More info - Flooding

Safe Cleanup Procedures

• Get the mess out. Remove all floodwater, dirt and debris left behind by the floodwater as soon as possible.
• Remove mold and mildew. Moldy or mildewed building materials should be thoroughly cleaned and dried or removed and replaced. Any materials or furnishings that soaked up water and cannot be cleaned thoroughly should be removed from the building.
• Check your flooring. Carpet and padding cannot typically be cleaned well enough. Throw them away.
• Dry out walls. Walls must remain open to allow them to completely dry. Plaster, brick and concrete block walls can probably be cleaned, disinfected and completely dried.
• Salvage what you can. Personal property and furnishings that are wet for 24-48 hours after floodwater recedes, will most likely have mold growing in or on them. Clothing and linens may be salvaged by washing with detergent.
• Discard porous materials that cannot be laundered and disinfected.
• Do not re-enter flooded buildings until electricity is shut off, gas lines are secured and the structure is deemed safe.
• Avoid direct contact with contaminated materials and damp vegetation.
• Do not eat, drink, or smoke in contaminated areas; wash hands frequently.
• Do not mix cleaning products together or add bleach to other chemicals. Mixing cleaning products can create toxic vapors. Follow the directions on the label.
• Ensure your tetanus vaccinations are up to date.

Mud Cleanup FAQ

Is the mud/sediment around/in my home safe?

• We know that flooding is a hazard and can make your house unsafe. That’s why we are providing guidance for cleaning up to restore your home. The cleanup guidance is based on national standards for flood-impacted communities. Following this guidance helps mitigate common flood hazards, including things like flood-carried mud and sediment. 
• We also encourage homeowners to dry out their belongings and mud outside in the sun. Sunlight helps kill microbes.

Will DOH test the mud/sediment?

• Yes, as the Governor announced, mud will be tested, in coordination with partner organizations. However, you don’t need to wait to clean up your home. Follow the recommended methods and guidance to safely clean up.

Mold Cleanup and Prevention

Mold growth can begin quickly after flooding and may pose health risks.

• Any indoor mold should be addressed promptly.
• Before cleaning, lightly spray moldy surfaces with a soapy solution to reduce airborne particles.
• Clean with soap and water, then disinfect using a bleach solution (1 cup bleach to 1 gallon of water). Open windows and doors first. Never mix bleach with other cleaning products containing ammonia. Use as directed on label.
• Allow at least 15 minutes of contact time, then rinse and dry thoroughly.
• Promote airflow to speed drying and prevent regrowth.

Discard materials that cannot be safely cleaned:

• Carpets, mattresses, upholstery and other porous items wet for more than 24–48 hours
• Items that cannot be laundered or disinfected

Clothing and linens may be salvaged by washing with detergent and bleach.

Recommended Personal Protective Equipment (PPE)

When cleaning or entering affected areas, wear:

• Waterproof boots (steel toe/shank recommended)
• Rubber or heavy-duty gloves
• NIOSH-approved N95 mask
• Sealed safety goggles
• Long sleeves, long pants, or protective coveralls
• Hard hats where debris hazards exist

Power Outage and Food Safety

Food may not be safe after a power outage — even if it looks or smells normal.

• Refrigerated food lasts less than four hours without power.
• Frozen food lasts:
  
  • Up to 24 hours in a half-full freezer
  • Up to 48 hours in a full freezer (if unopened)
    ‍

Food safety tips:

• Never taste food to determine if it is safe.
• Throw away perishable foods after four hours without refrigeration.
• Discard any food with unusual odor, color, or texture.
• Discard food that has come into contact with floodwater.
• Food above 40°F should be thrown out.
• Frozen food with ice crystals or at 40°F or below may be safely refrozen or cooked.

When in doubt, throw it out.

Disease Risks and Prevention

Leptospirosis

• Caused by bacteria found in water contaminated with animal urine (especially rats).
• Enters the body through cuts or mucous membranes.
• Early symptoms: fever, chills, muscle aches.

Prevention:

• Avoid contact with floodwater, mud and damp materials.
• Cover cuts and wear protective clothing.
• Keep contaminated water out of catchment systems.

Seek medical care promptly if symptoms develop. Early treatment is critical.

More info - Leptospirosis

Rat Lungworm Disease

• Caused by a parasite carried by rats, slugs and snails.
• Risk increases after heavy rains.

Prevention:

• Wash all produce thoroughly, even if labeled “pre-washed.”
• Inspect leafy greens for slugs or snails.
• Wash hands after gardening or handling produce.
• Control pests by removing food sources, securing trash and eliminating standing water.

Seek medical attention if symptoms such as severe headaches, stiff neck, or neurological issues develop.

Mosquito Control

Standing water after flooding can increase mosquito populations.

• Drain standing water from containers, tarps, gutters and catchment systems.
• Cover water storage containers.
• Use EPA-approved insect repellent and wear protective clothing.
• Repair window and door screens.

Mosquitoes in Hawai‘i can carry diseases such as dengue, chikungunya and Zika. While these diseases are not currently present in Hawaiʻi, controlling mosquitoes is the best way to prevent them from occurring.

More info – Mosquito Control

When to Seek Medical Care

Seek medical attention if you experience:

• Signs of wound infection (redness, swelling, drainage, fever)
• Persistent cough, wheezing, or breathing difficulty
• Vomiting, diarrhea, or stomach pain after exposure
• Fever, headache, rash, or joint pain after mosquito bites or floodwater exposure
• A tetanus booster may be recommended for contaminated wounds.

Caring for Mental Health After a Disaster

Recovering from a disaster can take a toll on emotional well-being.

For individuals and families:

• Stay connected with family, friends and neighbors
• Limit repeated exposure to disaster-related media
• Maintain routines, rest and proper nutrition
• Practice healthy coping strategies

DOH Resources – Adult Mental Health Division

Supporting keiki:

• Reassure children they are safe
• Keep routines consistent
• Encourage open conversations about their feelings
• Limit exposure to distressing news
• Seek professional help if distress continues

DOH Resources – Child & Adolescent Mental Health Division

Support is available through the Hawaiʻi CARES crisis line. Call, text, or chat 988.

Additional Safety Reminder

Flood-damaged homes may not be safe to occupy until they are fully cleaned, disinfected and dried. Consult professionals when in doubt.

DOH encourages residents to take these precautions seriously to prevent illness and injury during recovery.

For more information, visit the Hawai‘i Department of Health website.