A Story from the Field: The Morning Wanna Opened the Packing Room Again

Wanna is the quality assurance manager at a mid-sized food processing plant in Kabin Buri district, Prachinburi province. The plant makes dried fruit snacks and bottled chili paste for shops and supermarkets across eastern Thailand. Every year she prepares documents, training records and the physical plant itself for GMP inspections and HACCP reviews, so she knows every corner of the building by heart: which drain gets blocked in the rainy season, which wall in the packing room tends to sweat, which door seal needs replacing before the auditors notice it.

This year the rain did not stop. After several days of heavy downpours, the Prachinburi River spilled over its banks and water pushed into the industrial area. Within hours it was knee-deep across the production floor. The team stopped the line abruptly, shut down the main power, and lifted whatever raw materials and finished goods they could onto higher racks. Then everyone went home to deal with their own flooded houses, and the factory sat in still, brown water for almost two weeks.

When the water finally receded, Wanna was the first person through the door of the packing room. The smell hit her immediately: a heavy, damp mustiness mixed with the sour odor of river mud. The epoxy floor was covered with sheets of drying clay. Every stainless-steel table leg carried a horizontal tide line showing exactly how high the water had risen. In the corners where the insulated wall panels met the floor, small black dots of mold had already appeared. The floor drains, normally the cleanest drains in the building, were pushing a sewer smell back up into the room. In the packaging store next door, the cardboard cartons on the bottom pallets had gone soft and were starting to grow green fuzz.

What worried her most, though, was not the damage she could see. It was a simple question she knew she would have to answer, to her managing director, to her customers and eventually to an auditor: "How do we prove this space is safe enough to make food for consumers again?" The sales team wanted the line running as soon as possible. A major customer had already called to ask about the restart schedule. But as the person responsible for quality, Wanna knew that if they rushed and contamination slipped through to the market, the damage to the brand would be far greater than a few extra days of downtime.

Wanna's situation is not unusual. Across Prachinburi, Chachoengsao, Ayutthaya and other provinces hit by the 2026 floods, food processors, bakeries, beverage bottlers and central kitchens are facing the same dilemma. This article explains why floodwater is such a serious threat to food production areas, why common clean-up shortcuts tend to fall short, and how a structured process combining disinfection fogging with ozone shock treatment can support a safe, well-documented restart.

Why Floods Are Such a Serious Threat to Food Factories

Floodwater is never just water. As it moves across a town, it picks up mud, overflow from sewers and septic tanks, animal waste, dead animals, fuel, agricultural chemicals and whatever else lies in its path. The World Health Organization notes that floods increase the risk of water-borne and food-borne disease. In a food plant, where the whole point of the building is to keep contamination away from the product, that risk is multiplied. It helps to break the problem down into three areas: health, business and time.

Health risks for consumers and employees

• Pathogenic bacteria. Organisms such as E. coli, Salmonella and Listeria can lodge in mud residue, in the joints of the floor, inside drains and underneath machinery. Listeria in particular is known for surviving in cool, damp places such as drains and wet floors. If any of these organisms reach the product, consumers can suffer diarrhea or food poisoning, and vulnerable groups such as children, older people and pregnant women face higher risks.
• Leptospirosis. Workers who wade into water and mud to clean up are at risk of leptospirosis, the disease Thais commonly call "rat urine fever." The bacteria enter through cuts on the hands and feet or through the eyes and mouth. Early symptoms such as fever and muscle pain are easy to mistake for flu.
• Mold and spores. Mold growing on walls, ceilings, insulation and packaging can release spores into the air. These spores can settle on product and packaging, shortening shelf life and causing spoilage. They can also trigger allergies and asthma in employees who spend long shifts indoors.
• Pests. Flies, cockroaches and rats are drawn to damp, dirty buildings after the water recedes, and they carry contamination from room to room.

Business risks

Every day the line is down is revenue lost and customer patience tested. Yet restarting too early, before the building is truly clean, can lead to something much worse: a product recall, a customer suspending orders, or serious findings at the next audit. GMP and HACCP systems put strong emphasis on site hygiene and on preventing contamination. After an abnormal event such as a flood, a plant needs a recovery procedure that is planned, verifiable and documented, so that management can show what was done and why the area was considered fit to resume production.

Reputation matters just as much as compliance. Food brands are built on trust. A single social media post about a strange taste, a moldy jar or a sick child can undo years of careful marketing. In a region where several factories were flooded at the same time, buyers will be watching closely to see which suppliers recover responsibly.

Time and manpower pressure

After a flood, many employees are still repairing their own homes, so the plant is short of hands just when it needs them most. If the clean-up method is not thorough and areas have to be cleaned and disinfected again and again, the timeline stretches and costs balloon. Overtime, rented equipment, discarded materials and delayed orders add up quickly. A process that gets it right the first time is not just safer; it is cheaper.

Why the Usual Clean-Up Shortcuts Often Fall Short

Most factories already have strong cleaning routines. The challenge after a flood is that the contamination load is far heavier and far more widespread than anything those daily routines were designed for. Here are the shortcuts we see most often, and why they are rarely enough on their own.

• Relying on bleach alone. Chlorine bleach loses strength quickly when it meets mud and organic matter, which is exactly what a flooded floor is covered with. It has a strong smell, can corrode some metals and seals, and may leave a chlorine odor that is unwelcome in a food production area. It is also hard to apply evenly to walls, ceilings and the underside of equipment.
• Running fans to dry everything out. Fans make surfaces look dry faster, but moisture trapped inside insulated panels, under floor coatings and inside pipes stays put. Worse, strong airflow can lift mold spores and spread them across the room and into areas that were not contaminated before.
• High-pressure washing only. Pressure washers are excellent for removing visible dirt, but the spray creates aerosols that can carry microorganisms onto surfaces that have already been cleaned. Without a disinfection step afterwards, the plant can end up redistributing contamination rather than removing it.
• Air fresheners and fragrance. These only mask odor, and they should never be used in food production areas because fragrance can transfer to the product. If you can still smell mustiness, the source is still there.
• Painting over mold stains. A fresh coat of paint makes a room look new, but mold underneath will return if moisture remains. Paint that later blisters and flakes becomes a foreign-material risk, which is precisely what food safety systems try to prevent.

The common weakness of all these methods is reach. Food factories are full of hard-to-reach places: under conveyors, behind control cabinets, inside cable trays, above suspended ceilings, inside air ducts and along the backs of storage racks. These hidden spots are where contamination survives, and they are the reason clean-up efforts sometimes seem never to end. A recovery plan needs a way to treat both surfaces and the air, including the places a cloth or a mop simply cannot touch.

The Solution: Chemgene HLD4H Disinfection Fogging Plus Ozone Treatment by World Health Disinfection

World Health Disinfection (WHD) provides a professional disinfection fogging service using Chemgene HLD4H, a high-level disinfectant with broad activity against bacteria, viruses and fungi. The solution is applied with ULV (ultra-low volume) foggers that turn it into a fine mist. Because the droplets are so small, they drift into corners, under machinery and up to high structures that manual wiping cannot reach.

This is paired with our ozone shock treatment service. Ozone is a reactive gas that fills the whole room, reaching ceiling voids, ducts and the air itself. It helps deal with airborne mold spores and breaks down the odor molecules responsible for the musty, muddy and drain-like smells that linger after a flood. The two steps complement each other: fogging treats surfaces, while ozone treats the air and the spaces that mist cannot easily reach.

Our step-by-step process for food factories

1. Site survey and risk zoning. Our team walks the site with your quality and maintenance staff. Together we divide the plant into zones by risk level, for example raw material receiving, processing, packing, packaging storage, finished goods warehouse, changing rooms, canteen and offices. This zoning shapes the order of work so that clean areas are never re-contaminated by dirty ones.
2. Mud removal and pre-cleaning advice. Disinfection works best once mud and soil have been removed. We advise on cleaning from top to bottom and from cleaner zones toward dirtier zones, on flushing floor drains, and on which materials are better discarded, such as paper packaging and cardboard that sat in floodwater.
3. Disinfection fogging with Chemgene HLD4H. We fog the floors, walls, ceilings, machine frames, drains and removable equipment. For food-contact surfaces, the plant should then rinse and sanitize again according to its own sanitation standard operating procedures (SSOP) before production starts, so that the process fits your GMP/HACCP system.
4. Ozone shock treatment. The room is sealed and the ozone generator runs for a period suited to the room's volume and condition. This targets mold spores in the air, in ceiling voids and in ductwork, as well as odors absorbed into materials.
5. Ventilation. After treatment, the ventilation system runs until ozone levels fall back to a safe level. Only then are employees allowed back in.
6. Re-check and handover. We walk the area again with your quality team to check odor and condition. Your team can then carry out its own verification steps, such as surface swabs or air sampling, and file the results as part of your records.

Why combine the two methods?

Think of a flooded production hall as having two layers of problems. The first layer is on the surfaces: mud residue, biofilm in drains, bacteria on machine frames and mold on walls. The second layer is in the air and in hidden volumes: floating spores, odor molecules soaked into insulation and contamination inside ceiling voids and ducts. Fogging is the right tool for the first layer, and ozone is the right tool for the second. Using only one leaves half the problem in place, which is why many plants that rely on a single method end up with odor or mold returning a week or two after restart.

10 Reasons Food Factories in Kabin Buri Choose WHD for Flood Recovery

1. We understand food production environments. Work is sequenced by risk zone so that clean areas are not re-contaminated.
2. We use Chemgene HLD4H, a high-level disinfectant with broad activity against bacteria, viruses and fungi.
3. ULV fogging reaches every gap, including under conveyors, behind machines and high structures that cloths and mops cannot reach.
4. Ozone treatment targets airborne mold spores, reducing the chance that mold settles back onto walls and packaging.
5. Musty and muddy odors are broken down, not masked, so no fragrance ever needs to come near your product.
6. Less downtime. We plan around your shifts and can work outside normal production hours by arrangement, zone by zone.
7. Worker safety is built in, with clear area isolation, signage and ventilation before re-entry.
8. Machinery and electronics are protected. Sensitive parts are covered or removed and ozone dose is controlled.
9. Whole-site coverage, from production rooms and warehouses to changing rooms, canteens and offices, with an optional mosquito spraying service around the buildings.
10. Easy to reach and quick to coordinate. Call 065-556-6294 or message LINE @whd268 to arrange a site survey.

Before and After Disinfection Fogging and Ozone Treatment

In Their Words: A Quality Manager's Perspective

"What we needed wasn't just a room that looked clean. We needed a sequence of work we could explain to anyone who asked. The team helped us zone the plant, advised us on the cleaning order, then did the fogging and ozone treatment back to back. When we opened the packing room again, the musty smell that had been stuck in my nose for days was gone, and my team could move straight on to our own verification steps."

— Wanna, Quality Assurance Manager, food processing plant, Kabin Buri (field scenario)

Restart Checklist for Food Factories After a Flood

Every plant is different, and your own food safety team and system documents should always lead the decision to restart. The checklist below is a practical starting point that many plants find useful.

• Electrical safety first. Have qualified electricians inspect motors, control panels and wiring before power is restored. Water and electricity are a deadly combination.
• Segregate affected materials. Separate raw materials, packaging and finished goods that touched floodwater, then decide to discard or hold them according to your system. When in doubt, throw it out.
• Remove all mud. Shovel and scrape out sediment, wash surfaces from top to bottom, and flush every floor drain and trench.
• Disinfect the whole area, then rinse and sanitize food-contact surfaces again according to your SSOP.
• Treat airborne mold and odor with ozone, followed by thorough ventilation.
• Check the water supply. Confirm that the plant's process water and storage tanks were not contaminated by floodwater.
• Review pest control. Inspect for signs of rats and insects around the building and update bait station maps if needed.
• Verify and record. Carry out your own cleanliness verification, such as swabs or ATP tests, and keep records of every step for future audits.
• Protect your people. Make sure staff who worked in water wear boots and gloves, and watch for fever or muscle pain, which can be early signs of leptospirosis. Encourage anyone with symptoms to see a doctor promptly.
• Communicate with customers. A short, factual update on your recovery plan reassures buyers and protects relationships while production is paused.

Frequently Asked Questions (FAQ)

Q: Can disinfection fogging replace cleaning?
A: No. Fogging is most effective after mud and visible soil have been removed. Our team will recommend a cleaning sequence that suits your plant layout before we begin.

Q: What should we do with food-contact surfaces after fogging?
A: Rinse and sanitize them again according to your plant's sanitation standard operating procedures before production restarts, so the process fits within your GMP/HACCP system.

Q: Is ozone treatment safe inside a food factory?
A: Yes, when it is done correctly. That means no people, animals or plants in the area, all raw materials and products removed, controlled concentration and time, and full ventilation before anyone goes back in.

Q: Will ozone damage our machines or rubber parts?
A: High ozone concentrations can make rubber and some electronics age faster. That is why we control the dose and cover or remove sensitive components such as gaskets, seals and control electronics before treatment.

Q: How long until we can restart production?
A: It depends on the size of the site and the level of damage. After the survey we plan the work with you, and we can treat the plant zone by zone so that some lines can restart earlier.

Q: Can you work at night or on weekends?
A: Please contact us at 065-556-6294 or LINE @whd268 to discuss scheduling that suits your production plan.

Q: Do you cover warehouses and offices as well?
A: Yes. Warehouses, changing rooms, canteens and offices often flood at the same time and can be included in the same plan.

Get Your Line Ready Before Your Product Reaches Consumers

Don't let hidden germs and mold left behind by the flood become a risk to your brand. Talk to the World Health Disinfection team today.

See Our Disinfection Service – Click Here

Book Ozone Treatment – Click Here

Call 065-556-6294 | LINE @whd268 | Email worldhealthdisinfection@gmail.com

Related Links

• Ozone treatment for odor and chemical residue removal
• Master Ozone Generator
• Chemgene HLD4H disinfectant spray 750 ml
• All articles from WHD
• External sources: WHO – Floods and health and Department of Health, Thailand