Floods leave more than just water damage in their wake. The aftermath of a flood is filled with hidden dangers—contaminated water, toxic mould, structural instability, and even life-threatening diseases. While the instinct may be to start cleaning up as quickly as possible, rushing in without proper precautions can put your health and safety at serious risk.

Floodwaters contain sewage, bacteria, chemicals, and hidden debris, making every step in the cleanup process a potential hazard. Standing water and damp environments become breeding grounds for mould within just 24-48 hours, worsening air quality and causing respiratory issues. Meanwhile, submerged electrical systems, weakened foundations, and unstable structures pose significant physical dangers that can go unnoticed until it’s too late.

Cleaning up after a flood requires more than just mops and buckets—it demands a strategic, safety-first approach. In this guide, we’ll walk you through:

• The health risks of flood cleanup, including waterborne diseases, mould exposure, toxic contamination, and structural hazards.
• Essential precautions to take before stepping into a flooded area.
• Step-by-step safe cleaning procedures to help you remove floodwater, disinfect surfaces, and prevent mould growth.
• Personal safety tips to protect yourself from injuries, infections, and other post-flood dangers.
• When to call professionals for mould removal, electrical repairs, or hazardous waste cleanup.

What are the health risks after a flood?

From contaminated water to hidden structural hazards, post-flood environments are riddled with risks that can threaten your health and safety. Before stepping into a flooded area, it's essential to understand the potential dangers and take the necessary precautions to protect yourself and those around you.

1. Waterborne diseases & contaminants

Floodwaters are often a toxic cocktail of sewage, chemicals, bacteria, and viruses, making direct contact or accidental ingestion incredibly dangerous. Even clean-looking water may contain microscopic pathogens that can cause serious illnesses.

Some of the most common waterborne diseases include:

• Cryptosporidiosis & E. coli – These bacterial infections can cause severe diarrhoea, vomiting, and stomach cramps, leading to dehydration if untreated.
• Hepatitis A – A viral infection that spreads through contaminated water and affects the liver, causing fever, nausea, jaundice, and fatigue.
• Leptospirosis – Caused by bacteria found in floodwater contaminated by animal urine, this disease can lead to high fever, muscle pain, chills, and, in severe cases, kidney or liver damage.

Drinking, bathing in, or even accidentally swallowing floodwater can expose you to these harmful pathogens. Additionally, contaminated food and water sources left in flooded areas can continue to spread disease long after the flood has passed.

2. Mould and fungal growth

Flooded homes and buildings create the perfect conditions for mould (mildew) and fungal spores to spread rapidly. Within just 24-48 hours, damp walls, furniture, carpets, and insulation can become breeding grounds for mould.

Prolonged exposure to mould can cause:

• Respiratory problems – Coughing, wheezing, and shortness of breath, especially in people with asthma.
• Severe allergic reactions – Eye irritation, runny nose, and skin rashes.
• Chronic lung infections – For those with weakened immune systems, mould exposure can lead to serious fungal infections.

3. Toxic chemical exposure

Floods don’t just bring in water; they disrupt everything in their path. As a result, floodwaters may contain pesticides, industrial waste, oil, fuel, and hazardous household chemicals that can cause long-term health issues if handled improperly.

Risks of toxic chemical exposure include:

• Skin and eye irritation from coming into direct contact with contaminated water.
• Poisoning from inhaling fumes or accidentally ingesting toxins.
• Long-term health effects from exposure to carcinogenic substances found in industrial spills or fuel leaks.

Even after the water has drained, chemical residues may linger on surfaces, requiring thorough disinfection before an area is safe to use again.

4. Electrical and structural hazards

Waterlogged buildings can become unstable, with weakened foundations, ceilings, and walls at risk of sudden collapse. Additionally, live electrical wires in standing water create a major electrocution hazard.

Before entering a flooded building, always consider:

• Has the electricity been turned off at the main switch? If not, do not enter.
• Is there visible structural damage? Cracks, bulging walls, and sagging ceilings are red flags.
• Are support beams and flooring still stable? Weak floors may give way underfoot.

If a building looks unsafe, do not attempt to enter without professional assessment. Structural and electrical hazards are often invisible until it’s too late.

5. Injury risks & tetanus concerns

Floodwaters conceal sharp debris, broken glass, and hidden objects, increasing the risk of deep cuts, puncture wounds, and lacerations. These injuries can quickly become infected, especially if exposed to contaminated water.

One major concern is tetanus, a bacterial infection that thrives in dirty wounds and can lead to muscle stiffness, lockjaw, and life-threatening complications. Anyone involved in flood cleanup should ensure their tetanus vaccinations are up to date.

Precautions before starting flood cleanup

Cleaning up after a flood is a task that requires careful preparation, the right protective gear, and a clear safety plan. Before you begin, take these critical precautions to protect yourself and ensure a safe cleanup process.

Check for safety hazards first

Flood-damaged buildings can be unstable, and floodwaters can conceal life-threatening dangers beneath the surface. Never enter a flooded area without thoroughly assessing the risks first.

• Check structural stability – Inspect walls, ceilings, and floors for cracks, bulging, or sagging. If the structure appears unstable, do not enter.
• Turn off electricity and gas – Water and electricity are a deadly combination. If you suspect flooding has affected electrical wiring, turn off the power at the main switch before entering. Likewise, gas leaks can pose a fire risk—turn off the gas supply if safe to do so.
• Use a tool to check for hidden hazards – Standing water can obscure sharp debris, broken glass, or unstable flooring. Use a stick, shovel, or long-handled tool to probe ahead before taking each step.
• Watch out for animals – Floodwaters may displace snakes, rats, insects, and even reptiles seeking shelter in homes and debris. Proceed with caution and wear thick boots to protect against bites and stings.

Use protective gear

Proper protective clothing is your first line of defence against contaminated water, mould spores, and harmful chemicals when doing the cleanups.

✅ Wear waterproof gloves and boots – Prevents exposure to sewage, bacteria, and sharp debris.

✅ Use a P2 face mask or N95 mask – Protects against mould spores, dust, and airborne contaminants.

✅ Wear safety goggles – Shields eyes from contaminated water, cleaning chemicals, and debris.

✅ Cover your skin – Wear long-sleeved clothing, long trousers, and a waterproof outer layer (like microporous-type coveralls) to minimise direct skin contact with flood residue.

Even after floodwaters recede, bacteria and mould spores remain airborne, making protective gear essential throughout the cleanup process—not just in the initial stages.

Shop all face masks and body PPE at Aussie Pharma Direct. 

Check for mould growth

Mould thrives in damp, flood-affected areas and can start growing within 24-48 hours of water exposure. Before beginning any cleanup, it’s crucial to inspect the affected area for signs of mould growth. Identifying problem areas early can help you determine which materials can be salvaged and which require professional remediation.

• Look for visible mould spots – Check walls, ceilings, skirting boards, carpets, and furniture for discolouration, fuzzy patches, or dark streaks that could indicate mould growth.
• Inspect hidden spaces – Mould often thrives in unseen areas, such as behind wallpaper, under floorboards, inside cupboards, and within damp insulation.
• Pay attention to musty odours – If an area smells stale or earthy, there may be mould growing out of sight, even if no visible signs are present.
• Note high-risk zones – Spaces with poor ventilation or prolonged moisture exposure—such as basements, bathrooms, and corners of flooded rooms—are especially prone to mould growth.

Read more: A Homeowner's Guide on How to Test, Clean & Prevent Mould Growth with SAN-AIR

Bonus Tip:

If you suspect mould but want a more precise assessment, you can use the SAN-AIR™ Mould Test Kit to detect mould presence on surfaces, in the air, or even in water. This kit provides a clear, scientific way to determine if mould is present, helping you decide whether professional remediation is needed or if immediate cleaning action can be taken.

SAN-AIR™ Mould & Bacteria Test Kit

If you identify widespread or severe mould infestations, consider consulting a professional for safe removal. Attempting to clean mould without the right protective gear can expose you to harmful spores, triggering asthma, allergies, and respiratory issues.

Sign up here to get our e-Book: When to DIY & When to Call a Pro: A Homeowner’s Guide to Mould Remediation

 

 

Ensure vaccinations are up-to-date

Exposure to flood-contaminated environments increases the risk of infections like tetanus, which can enter the body through cuts and wounds.

• Tetanus shots are strongly recommended for anyone involved in flood cleanup, especially if you haven’t had a booster in the last 10 years.
• If you have open wounds or cuts, keep them covered with waterproof dressings and avoid direct contact with floodwater.
• Seek medical advice if you develop signs of infection such as redness, swelling, fever, or worsening pain.

Check out more information on tetanus, vaccines and recommendations for vaccination from the Australian Immunisation Handbook.

Safe cleaning procedures after a flood

Once the immediate dangers of flooding have passed, the real work begins. Without proper cleaning and disinfection, flood-affected areas can become breeding grounds for disease, posing risks long after the water has receded.

To help you restore your home or workplace safely, follow these step-by-step cleaning procedures designed to remove contaminants, sanitise surfaces, and prevent further damage.

Step 1: Remove floodwater and debris

Before you begin scrubbing and disinfecting, the first priority is getting rid of standing water and any contaminated debris left behind.

• Pump out water gradually – If your space is severely flooded, remove water in stages to prevent sudden structural collapse due to pressure changes.
• Use shovels and heavy-duty bags – Clear out mud, sludge, and debris carefully, as floodwaters often deposit sharp objects, broken glass, and hidden hazards.
• Avoid direct contact with flood residue – Wear gloves, boots, and protective gear to minimise exposure to contaminated materials.
• Separate salvageable and non-salvageable items – Hard, non-porous items can often be cleaned and disinfected, but soft furnishings, carpets, and water-damaged insulation should be discarded.

⚠️ Never mix flood debris with regular household waste—check local guidelines for safe disposal of contaminated materials.

Step 2: Disinfect & sanitise affected areas

Once all visible debris and water are removed, it’s time to eliminate the unseen dangers—bacteria, viruses, and toxic contaminants that have seeped into surfaces.

• Wash all surfaces thoroughly – Use hot water and detergent to scrub walls, floors, and any hard surfaces that came into contact with floodwater.
• Disinfect with a bleach solution – Mix one part bleach with nine parts water to sanitise surfaces, paying special attention to kitchen areas, bathrooms, and high-touch surfaces.
• Bleach-free alternative – If you're looking for a gentler, natural alternative, try SAN-AIR™ LD Concentrate, which is ideal for disinfecting larger areas. For general cleaning, dilute 20ml of SAN-AIR LD Concentrate per litre of purified water. For heavily soiled areas, increase the concentration to up to 100ml per litre. Apply the solution to surfaces, wipe with a clean cloth, and repeat as necessary for thorough disinfection. For smaller areas or spot cleaning, SAN-AIR™ Surface Mould Remover Spray is a convenient, ready-to-use solution that’s perfect for quickly treating surfaces like kitchen benches, bathroom tiles, and other high-touch points. 
• Discard porous materials – Mould thrives in damp fabrics, paper, and insulation. If an item cannot be fully cleaned and dried, it must be thrown away to prevent future mould growth.
• Sanitise appliances and electrical items cautiously – If electronics have been exposed to water, do not turn them on until they have been inspected by a professional.

Tip: When using bleach or disinfectants, always ensure proper ventilation by opening windows and doors to avoid inhaling harsh fumes.

Step 3: Dry the area to prevent mould growth

After disinfection, it’s essential to fully dry the area to prevent mould from taking hold. 

• Use fans, dehumidifiers, and open windows – Air circulation helps dry out walls, flooring, and furniture faster.
• Remove water-damaged drywall and flooring – If moisture has seeped into walls or wooden floors, they may need to be replaced to stop mould from forming inside hidden cavities.
• Apply mould-prevention treatments – Use mould-killing sprays on high-risk areas, and consider placing SAN-AIR Mould Gone Reactive Gels with an Air Diffuser in enclosed spaces to help eliminate airborne mould spores and prevent regrowth.
• Discard severely mould-infested items – If an object is covered in mould and cannot be cleaned, do not attempt to salvage it—mould exposure can cause serious health problems.

⚠️ If mould has already spread over a large area (more than 10 square feet), professional remediation is recommended.

Step 4: Clean water sources and food storage areas

Floodwaters can contaminate drinking water supplies, food storage areas, and kitchen surfaces, leading to potential foodborne illnesses.

• Boil water before use – If the water supply has been affected, boil tap water for at least one minute before drinking or cooking.
• Dispose of contaminated food – Any food, beverages, or medicine that came into contact with floodwater should be thrown away immediately, even if they appear sealed.
• Sanitise kitchenware – Dishes, utensils, and cookware should be washed thoroughly with hot soapy water, then disinfected with a food-grade sanitiser solution. Check out the True Blue Wipeout Food Grade Sanitiser.
• Check refrigerated and frozen food – If the power was out for more than four hours, perishable food is no longer safe to eat and should be discarded.

Tip: When in doubt, throw it out. Consuming contaminated food or water can lead to serious illness.

Conclusion: Prioritising safety in food cleanup

The aftermath of a flood brings numerous risks, from contaminated water and mould growth to hidden structural dangers, making it crucial to approach the cleanup process with caution, the right protective measures, and a well-planned strategy.

By following safe cleanup procedures, including removing floodwater properly, disinfecting all affected areas, drying spaces thoroughly, and checking for mould growth, you can minimise long-term health risks and prevent future issues.

However, some situations require professional help. If you encounter severe mould infestations, extensive structural damage, or exposure to hazardous materials, seeking expert assistance is the safest course of action. When in doubt, your health and safety should always come first.

 

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Cleaning Products Mould Solutions PPE Safety & Protection Seasonal Care Tips