A Typical Scenario: The Chicken Rice Shop Racing to Open by Monday

Noi has run a small chicken rice and braised chicken noodle shop near the central market in Hat Yai, Songkhla, for almost twenty years. Her regulars range from office workers and students to older neighbours who come for breakfast every day. One night of relentless rain sent the U-Taphao canal and the street drains surging, and within hours muddy water had filled the shop almost to the edge of the chopping counter. The chicken fridge, the rice bin, bottles of sauce and boxes of noodles stored under the shelves sat underwater for nearly three days, with the power out the whole time.

When the water went down, Noi, her son and two staff shovelled out the mud, threw away dozens of bags of spoiled goods, hosed the floor, scrubbed the counters with dishwashing liquid and poured bleach over the kitchen floor. Noi was determined to reopen by Monday, because cash flow was tight and her staff needed wages. But on the Saturday before, when she opened the cupboard under the sink, a sour, rotten smell hit her so hard she shut it straight away. The wall behind the fridge had a long streak of green-black mold, and the drain outside still gave off a sewage smell whenever the day warmed up.

The question going round in her head was simple: if one of her elderly regulars got sick after eating here, what would happen to the name she had spent her life building, and how could she know the kitchen was genuinely clean enough? This scene plays out in restaurants, curry-and-rice stalls, cafés and hotel central kitchens in Hat Yai, Ayutthaya, Pathum Thani, Ubon Ratchathani and Sukhothai every time a big flood hits. The owners do not lack commitment. What they lack is the right sequence of work and tools that reach the places no one can see.

Understanding Salmonella and the Bacteria Floodwater Brings Into Kitchens

What is Salmonella?

Salmonella is a bacterium that lives in the intestines of people and animals, especially poultry, pigs and reptiles. It is shed in faeces, so it is commonly found in sewage, drains and septic tanks. When floodwater passes through those places and then into a restaurant, it carries the bacteria onto floors, walls, table legs, grout lines and every surface the water touches. Restaurants that already handle chicken, eggs and raw meat need to be especially careful about cross-contamination, because flood-borne bacteria can add to those already carried by ingredients.

Other germs to watch for in a flooded kitchen

• E. coli: an indicator of faecal contamination. Some strains cause severe diarrhoea.
• Listeria: a bacterium that can grow even at refrigerator temperatures, particularly dangerous for pregnant women, unborn babies and older adults. Fridges that lost power and came back on must be cleaned thoroughly.
• Gut viruses such as norovirus, which spread easily via hands and surfaces.
• Mold in dry stores, flour and rice sacks, cardboard boxes and on walls behind fridges. Some types produce toxins.
• Leptospira, the cause of leptospirosis, carried in the urine of rats that often escape floods by moving into kitchens and storerooms.

Where germs hide in a kitchen

Key risk points after a flood include floor and wall grout, under and behind stainless counters, cabinet legs and trolley wheels, floor drains and grease traps, fridge door gaskets and vents, under the sink, wooden chopping boards, wooden shelving, ridged plastic crates and damp hand towels. These places combine moisture, food scraps and warmth, the three things bacteria like most. Damp kitchen air can also carry mold spores onto utensils and uncovered ingredients.

Symptoms of Salmonella infection

People infected through contaminated food or utensils typically develop diarrhoea, fever, stomach cramps, nausea and vomiting, usually starting between six hours and six days after exposure. Most recover within a few days, but some become severely dehydrated or develop a bloodstream infection, which can be life-threatening. Anyone with severe diarrhoea, bloody stools, high fever or signs of dehydration, such as passing little urine, a dry mouth or dizziness, must see a doctor straight away.

Who is most at risk?

Groups at higher risk of severe illness include children under five, older adults, pregnant women, people with chronic conditions such as diabetes, kidney or liver disease, and people with weakened immune systems. Most community restaurants serve these customers every day. After a flood, when many families still cannot cook at home, local restaurants become a main source of meals, which raises the restaurant's responsibility even further.

Important: Any owner or staff member who waded through floodwater and then develops a fever, muscle pain (especially in the calves), red eyes or diarrhoea should stop preparing and serving food and see a doctor immediately, mentioning the flood exposure. Ozone treatment manages the restaurant environment. It is not medical treatment and it does not replace food hygiene practice.

What Can Go Wrong if You Reopen Too Soon

Health of customers and staff

One contaminated pot or chopping board can make dozens of customers ill on the same day. Kitchen staff, who touch risky surfaces all day, are likely to be infected first, and a sick staff member can unknowingly pass germs on through their hands.

Money

A restaurant that has just lost stock and equipment to a flood cannot afford a second blow. A food poisoning incident could force another closure, the loss of a whole new batch of ingredients, another round of cleaning, and possibly medical costs or compensation. That is far heavier than spending a few more days preparing the kitchen properly.

Time

Closing a second time after reopening costs many times more time than preparing well the first time, because everything must start again: discarding, washing, disinfecting and rebuilding customer confidence.

Reputation

Restaurants survive on trust. A single review saying "I got sick after eating here," or a customer's photo of mold on the kitchen wall, can spread through community Facebook groups and review apps overnight. Twenty years of reputation can collapse in a week, and delivery platforms pay close attention to ratings.

Family and team

Most small restaurants are family businesses. The shop's income pays school fees, parents' medicine and the wages of staff who are flood victims themselves. One mistake affects not just the owner but several families who depend on the shop.

Why the Cleaning Most Restaurants Do Is Not Enough

1. Scrubbing with dishwashing liquid alone. Detergent removes grease and visible dirt, which is an essential first step, but it is not designed to disinfect. A surface that looks spotless may still carry bacteria.

2. Flooding the kitchen with strong bleach. Chlorine is an effective disinfectant on hard surfaces, but it must be diluted to the right strength and rinsed from food-contact surfaces as directed. Overly strong solutions in a poorly ventilated kitchen create irritating fumes, and liquid cannot reach the air, the space behind cabinets, under counters or a damp ceiling.

3. Burning incense or setting out coffee grounds. These only mask odour, do nothing to reduce germs, and incense smoke adds irritants to kitchen air.

4. Repainting over moldy walls. The shop looks great on opening day, but if the wall is still damp, mold returns within weeks and may flake off near food preparation areas.

5. Keeping ingredients that look fine. Rice sacks, sauce bottles or dry goods touched by floodwater may be contaminated even if they look undamaged. Reluctance to throw them away is the biggest risk in the kitchen. The widely used rule is: when in doubt, throw it out.

What most restaurants lack is not effort but a complete sequence of work, and a tool that reaches the air and corners that cloths and brushes cannot.

The Right Kitchen Preparation Sequence, and Where WHD Ozone Treatment Fits

World Health Disinfection (WHD) provides residential and building ozone disinfection covering shops, offices, hotels, factories and many other types of building. Before reaching the ozone stage, however, a restaurant must always complete the basics. The recommended order is:

1. System safety. Shut off gas and power. Have technicians check wiring, sockets, fridges and gas burners before use. Make sure the water supply is safe, and follow any local water-quality advisories.
2. Sort and discard. Throw away all food and ingredients that touched floodwater, food from fridges and freezers that lost power for a long time, dented, swollen or rusty cans, wooden chopping boards, cracked containers, and absorbent materials that cannot be cleaned.
3. Remove mud and wash. Work from high to low, scrub grout, flush drains and grease traps, and dismantle removable equipment parts for washing.
4. Sanitise food-contact surfaces. Use a sanitiser suitable for food-contact surfaces at the concentration and contact time the manufacturer specifies. For surface disinfectant products, see Chemgene.
5. Dry. Use fans and dehumidifiers until walls, ceilings and cabinets are completely dry.
6. Ozone treatment. Disinfect the air and hard-to-reach corners and break down lingering musty and sewage odours.
7. Prepare to reopen. Buy fresh ingredients, wash utensils again, retrain staff on handwashing and try a soft opening with a limited menu.

How ozone works in a restaurant

Ozone gas (O3) is a strong oxidiser. Released into a closed space, it spreads through the whole room, including the dining area, kitchen, dry store and toilets. It breaks down the cell structures of viruses, bacteria and mold and breaks apart odour molecules, then reverts to oxygen (O2). It therefore leaves no chemical residue on tables, chairs or counters, a real advantage anywhere food is involved.

According to the test results certified for the company by Thailand's Department of Medical Sciences and Intertek (UK), ozone treatment eliminates viruses, bacteria and mold by 99.99%. See the certification documents.

The ozone process in a restaurant

1. Survey. The team checks the floor area, the flood line and the spots with odour or mold, then divides the premises into zones such as kitchen, storeroom, dining area and toilets.
2. Preparation. Remove all food, ingredients and condiments from the zone. Turn off gas and non-essential appliances. Take out plants and fish tanks. Close doors and windows.
3. Confirm the space is empty. Make sure all staff, customers and pets have left, and post no-entry signs.
4. Ozone release. The gas spreads through the zone.
5. Contact time. A typical cycle takes about 30 minutes per zone, depending on size and severity.
6. Rest and ventilation. The machine is switched off, the ozone reverts to oxygen, and the zone is ventilated before anyone returns.
7. Handover. The team reports back and advises on ongoing humidity and hygiene control.

Safety first: Ozone treatment is done only in an empty, closed space. All people, pets and plants must leave the premises and may return only after the rest and ventilation period is complete. Remember too that ozone comes after mud removal, washing, sanitising food-contact surfaces and drying. It does not replace any of them.

10 Reasons Restaurant Owners Choose Ozone Before Reopening After a Flood

1. No chemical residue in food areas. Ozone reverts to oxygen, leaving no film on dining tables or counters.
2. Disinfects the kitchen air, reducing airborne mold spores ready to settle on utensils.
3. Reaches where brushes cannot: behind fridges, under counters, inside vents and above the ceiling.
4. Breaks down sewage and musty odours, so the first customer through the door is not put off. Read more about the ozone cleaning service.
5. Backed by testing. Test results certified for the company by the Department of Medical Sciences and Intertek state 99.99% elimination of viruses, bacteria and mold.
6. Fast. Around 30 minutes per zone plus ventilation, possible the day before reopening without extra days of closure. See the ozone service for shops and buildings.
7. Covers the whole restaurant in one job: kitchen, storeroom, dining room and customer toilets.
8. A reassuring, honest message. You can truthfully tell customers the shop was cleaned and ozone-disinfected before reopening.
9. Helps slow mold's return when combined with humidity control in the dry store.
10. Free medical-grade disinfectant spray with ozone jobs of 15,000 baht or more, useful for high-touch points like door handles, the till and menus.

Before and After: A Restaurant Ready for Customers

Example Case: A Roadside Curry-and-Rice Shop in Pathum Thani

This example case is an illustrative scenario based on common situations, used to explain the process. It is not a review from any specific customer.

Somsri runs a two-unit shophouse curry-and-rice restaurant in Lat Lum Kaeo, Pathum Thani, serving hundreds of plates a day to factory workers and students. Floodwater stood about half a metre deep for five days. Afterwards, her family threw out all their ingredients, washed the shop and planned to reopen immediately because customers were waiting. When the team surveyed the site, however, they found the enclosed back storeroom walls still very damp, water stains on the ceiling above the stoves, and sediment still sitting in the kitchen drains.

The team advised postponing ozone treatment by two days so the shop could flush the drains and grease trap, run a dehumidifier in the storeroom, and finish sanitising food-contact surfaces. Once everything was ready, the team treated three zones, the kitchen, the storeroom, and the dining area with toilets, in the afternoon after everyone had left, then waited for the rest period and ventilation before the family came back in to prepare.

On reopening day, Somsri said the first thing her regulars mentioned was that the shop did not smell of floodwater at all, unlike several others nearby. She put up a small sign honestly telling customers that the shop had discarded old stock, washed, disinfected and been ozone-treated. What impressed her was that the team was willing to delay the job instead of rushing it, because treating while walls are still damp would only let mold come back.

Restaurant Reopening Checklist After a Flood

Before ozone

• Have electrical, gas, fridge and freezer systems checked before use.
• Discard food, ingredients and condiments that touched floodwater or sat in fridges without power for a long time.
• Discard wooden chopping boards, cracked containers and contaminated absorbent materials.
• Flush drains, grease traps, grout lines and under counters.
• Thoroughly clean and sanitise fridges, freezers and door gaskets.
• Sanitise food-contact surfaces with a suitable product, following the manufacturer's instructions.
• Dry walls, ceilings and storerooms completely.
• Check with your local public health office or municipality for any additional reopening guidance.

On ozone day

• Remove all food, ingredients and condiments from the premises.
• Turn off gas, remove plants and fish tanks, and close doors and windows.
• Make sure everyone leaves and post no-entry signs.

After ozone and on reopening day

• Wait for the full rest and ventilation period before re-entering.
• Wash utensils and equipment again before service.
• Buy fresh ingredients from trusted suppliers and store raw and cooked foods separately.
• Staff should wash hands with soap often and not handle food if they have diarrhoea, vomiting or fever.
• Control humidity in the dry store and check walls weekly for the first month.
• Anyone, staff or customer, with unusual symptoms should see a doctor promptly.

Frequently Asked Questions

If we use ozone, can we skip sanitiser on chopping boards and counters?
No. Food-contact surfaces must always be washed and sanitised according to food hygiene practice. Ozone is an extra step for air, corners and odour after surface cleaning is done.

Can sealed ingredients that were flooded be used after ozone?
No. Food that touched floodwater should be discarded. Ozone does not make contaminated food safe, and all food should be removed from the space during treatment.

How long must we close for treatment?
A typical cycle is about 30 minutes per zone plus rest and ventilation. Small restaurants are often done within half a day. The team confirms timing after the survey.

Will an ozone smell linger on food or utensils?
Ozone reverts to oxygen and leaves no residue. There may be a faint clean smell, like air after rain, which fades with ventilation. We also recommend washing utensils again before use, as standard kitchen practice.

Can a shop inside a mall or food court be treated?
Yes, if the unit can be closed off and building management gives permission. The team coordinates timing and sealing accordingly.

What extra preparation do gas-fired kitchens need?
Close gas valves and extinguish all burners before work starts, and always have a technician inspect a flooded gas system before real use.

Reopen With Confidence and Welcome Your Regulars Back

Talk to the WHD team about a site survey and an ozone plan before your reopening day.

Get a Restaurant Ozone Quote

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

Promotion: free medical-grade disinfectant spray with ozone jobs of 15,000 baht or more.

Related Services and Reading

• Residential and Building Ozone Disinfection
• Chemgene Disinfectant
• Reducing Chemical Residue With Ozone
• Certifications and Test Results
• Contact Us

References

• World Health Organization fact sheets: Salmonella and food safety
• CDC: Floods, food and water safety after a flood

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