A Story from the Field: The Restaurant Nobody Ever Sees

May is thirty-five and runs a delivery-only kitchen out of a two-unit shophouse off On Nut Road in Phra Khanong district. There are no tables, no sign out front, and no dining room. There is just a small pick-up window where riders collect their orders. From that single kitchen she cooks for three different brands on the delivery apps: rice boxes, spicy salads, and desserts. Every part of her business depends on star ratings and the photos customers post.

During the 2026 floods, heavy rain fell several nights in a row. The water in the soi rose until the storm drain in front of the building began to flow backwards. Black water bubbled up through the floor drains in the kitchen and out of the grease trap behind the shop. For two days the kitchen floor sat under roughly a hand's span of water. The cartons of paper food boxes on the bottom shelves, the sacks of rice and flour, and the spare carrier bags were all soaked. One of the chest freezers went off when the power had to be cut.

When the water went down, May and her two staff shovelled out the mud, scrubbed the floor, and reopened for orders as fast as they could, because she was afraid of losing her regulars. Less than a week later the one-star reviews started arriving. "The food had a weird musty smell." "The box smelled like wet laundry." May sniffed the boxes still left in the carton and realised the paper had absorbed moisture and had grey mold spots along the edges. The kitchen itself had a constant drain smell and a stale, damp odor hanging in the air, even with the extractor fan running all day.

May has no shop front where customers can see how clean her kitchen is. The only thing they experience is how the food smells and tastes when they open the box. A small smell problem became a big business problem almost overnight.

Her situation is common in the sois around On Nut, Bang Chak, and lower Sukhumvit, where shophouses have been converted into compact delivery kitchens over the past few years. Many of them share the same weak points: old drainage, tight storage, no windows at the back, and a business model that leaves no room for a bad week of reviews.

Why Delivery Kitchens Are More Exposed Than Ordinary Restaurants After a Flood

Small spaces packed with stock. Cloud kitchens are designed to squeeze every square metre. Dry goods, packaging, and ingredients are stored close to the floor and right up against the walls. When water comes in, everything gets wet at once, and the moisture lingers in rooms that often have no windows at all.

Back kitchens sit on top of drains and grease traps. Many shophouses in Phra Khanong, On Nut, and Bang Chak still run on older drainage. When the public sewer is full, wastewater flows back up through floor gratings and grease traps, carrying rancid fat, food waste, and bacteria that coat the floor and the legs of every cabinet and fridge.

Packaging is your shop front. Paper boxes, paper bags, and plastic lids stored in cartons absorb moisture and odors very easily. A box that looks perfectly normal on the outside can carry a musty smell that transfers straight into hot food the moment it is packed.

Several brands, one kitchen. If the kitchen has a problem, the ratings of every brand that cooks there fall together. The damage is multiplied by however many virtual restaurants share the space.

The rider pick-up window. This is a high-traffic spot all day long. Shoes that have waded through floodwater track mud in again and again. Left unmanaged, the floor in front of the pick-up window becomes the source of germs that is physically closest to the finished food.

No time to close. Delivery margins are thin, and every day offline is a day of lost income and lost search ranking on the apps. That pressure pushes owners to reopen before the kitchen is truly ready, which is exactly what happened to May.

The Risks Every Kitchen Owner Should Understand: Customers, Staff, and the Business

Food poisoning and diarrhea. Floodwater and sewer backflow can carry E. coli and other germs that cause stomach illness. If food-contact surfaces, chopping boards, utensils, or ingredients have touched that water and have not been cleaned properly, those germs can end up in meals sent to customers. In a delivery business you may never hear about it directly; you simply see orders fall away.

Mold in dry goods and packaging. Rice, flour, spices, and paper boxes that have been wet can carry mold that is invisible to the naked eye. Any food or ingredient that has been in contact with floodwater should be thrown away. It is not worth the risk of trying to save it.

Kitchen staff. Staff who wade through water during the clean-up are at risk of leptospirosis if they have cuts on their feet or legs. Anyone who develops a high fever or muscle pain, especially in the calves, after contact with floodwater should see a doctor and mention the exposure. Staff with allergies may also find themselves sneezing, coughing, or congested when working in a kitchen full of mold spores.

Ratings and app ranking. A handful of poor reviews can push a restaurant down the search results, and climbing back up takes far longer than restoring the kitchen ever would. For many delivery brands, ratings are the single most valuable asset they own.

Electricity and gas. Sockets, plugs, freezers, and cookers that were underwater must be checked by a qualified electrician before being switched back on. Gas lines and burners should be checked for leaks by a technician. If you smell gas at any point, leave the building and call for professional help immediately.

What the Kitchen Team Can Do Before Calling in Professionals

• Be ruthless about discarding. Throw away every ingredient, dry good, sauce, and piece of packaging that touched floodwater or sat in a wet carton. The same goes for food in freezers that were off long enough that you cannot be sure of the temperature.
• Remove the mud and grease first. Scrape mud off the floor, cabinet legs, the underside of stainless steel counters, and the floor channels. Wash with a degreaser and clean water. Disinfectants work best on surfaces that are already clean, so this step matters more than most people think.
• Have the grease trap pumped. A trap that took in sewer backflow is usually full of sludge. Have a contractor pump and wash it, and check that the drain pipes are not cracked or blocked.
• Wash utensils and equipment. Pots, woks, ladles, chopping boards, and storage tubs should be washed with detergent and then sanitised using a method that is safe for food-contact items. Wooden chopping boards that were submerged should be replaced.
• Get everything off the floor. Rearrange shelving so dry goods and packaging sit at least a hand's span above the floor and away from any wall that was wet.
• Bring in the right trades. An electrician for the sockets and appliances, a gas technician for the lines and burners, and a refrigeration technician for any freezer or chiller that sat in water.

For quick wipe-downs of high-touch points during service, such as freezer handles, the pick-up window ledge, and the packing table, you can use CHEMGENE HLD4H disinfectant spray according to the label, paying particular attention to the instructions for food-contact surfaces.

A Practical Reopening Checklist for Delivery Kitchens

When you are under pressure to get back online, a short checklist stops important steps from being skipped. Owners who have recovered well after floods tend to work through something like this before they switch their brands back on:

1. All flood-touched food and packaging has gone. Not just the obviously wet items, but whole cartons that sat on lower shelves.
2. Electrical and gas checks are complete. Every appliance that was in the water has been inspected and signed off by the appropriate technician.
3. Drains and the grease trap are clear. No standing sludge, no backflow smell when water runs.
4. Surfaces are clean, then disinfected. Mud and grease removed first, then a professional disinfection of floors, lower walls, under-counter spaces, and storage areas.
5. The air smells neutral. If you can still smell drains or mustiness when you walk in after the kitchen has been closed overnight, customers will be able to taste it.
6. Food-contact surfaces are prepared for cooking. After any disinfection or ozone treatment, food-contact surfaces are wiped or rinsed according to the product label before the first service.
7. New packaging is stored properly. Off the floor, away from damp walls, in a room that no longer smells musty.
8. The pick-up area is protected. A washable mat, a hand-washing or sanitising point for staff, and a clear routine for mopping the floor in front of the window.

It can also help to soft-launch: reopen one brand at reduced hours for a day or two, check how the kitchen performs and how the food smells after packing, and only then turn every brand back on. That way any lingering problem shows up in a small number of orders rather than across your whole business.

The Fixes Kitchens Try That Do Not Solve the Problem

• Flooding the kitchen with strong bleach. The chlorine smell can get into the food, it stings staff's eyes and noses, and mixing it with certain bathroom cleaners can release dangerous gas. It also does nothing about the musty odor soaked into the ceiling and walls.
• Running the extractor fan all day. Good for clearing smoke, but it does not kill the mold growing in cabinet gaps, under counters, and inside drains.
• Burning incense or using air fresheners. A floral scent mixed with food smells makes the meal seem even stranger to customers, and some fragrance products should not be used near food at all.
• Painting over mold stains. Living mold under the paint pushes the new coat into bubbles and reappears within a few weeks.
• Using the old boxes because throwing them away feels wasteful. You might save a few hundred baht, but you risk losing far more in reviews and regular customers.

The Solution: Professional Disinfection Fogging and Ozone Treatment for Delivery Kitchens by WHD

World Health Disinfection (WHD) provides disinfection fogging and ozone treatment for cloud kitchens, shared commissary kitchens, back-of-house kitchens, dry stores, and packaging rooms in Phra Khanong, On Nut, Bang Chak, and nearby areas. We plan the work so that your kitchen is offline for as short a time as possible.

Disinfection fogging with CHEMGENE HLD4H. Once the kitchen has been cleared of mud and grease, our team applies CHEMGENE HLD4H using an ultra-low-volume (ULV) fogger. The fine mist reaches under counters, behind freezers, along the lower walls, into floor channels, across storage shelving, and over the floor in front of the pick-up window, helping to reduce bacteria, viruses, and mold on surfaces. Before cooking resumes, surfaces that come into direct contact with food are wiped or rinsed according to the label instructions.

Ozone treatment. After fogging, the team runs an ozone generator in the closed kitchen and storage rooms. Ozone helps reduce airborne mold spores and breaks down the molecules behind musty odors, drain smells, and old grease odors that have soaked into the ceiling, walls, and extraction ducting.

Kitchen safety. Before work begins, all ingredients, food, and new packaging must be removed or sealed. No people, pets, or plants may be in the space while ozone is running. The team controls the dose and duration to suit the size of the kitchen, because high concentrations of ozone over long periods can make freezer door seals and some rubber parts age faster. Order printers, tablets used for receiving orders, and other electronics are moved out or covered. After treatment, doors are opened and extractor fans are run for the ventilation time the team recommends before staff go back in.

How the Work Is Done in a Delivery Kitchen

1. Site survey. We check how high the water rose, where the sewer backflow came in, the grease trap, the dry store, the freezers, and the pick-up window, and agree a closing slot that falls in your quietest ordering period.
2. Preparation advice. You receive a clear list of what to discard, what to move out, how far to take the degreasing, and which electricians, gas technicians, and grease trap contractors should finish their work before our visit.
3. Disinfection fogging. CHEMGENE HLD4H is fogged throughout the kitchen, storage rooms, staff toilet, and rider pick-up area.
4. Ozone treatment. The space is closed and the generator runs for the set time with nobody inside.
5. Ventilation. Doors and extractor fans are opened so the ozone can break down before the kitchen team returns to wipe food-contact surfaces and restock.
6. Re-check. We check odors and mold spots with the owner and give advice on packaging storage and a routine for cleaning floor drains.

10 Reasons Phra Khanong Delivery Kitchens Choose Fogging and Ozone Before Reopening

1. ULV disinfection fogging reaches under counters and behind freezers where a cloth cannot.
2. It helps reduce germs left by sewer backflow on floors, lower walls, and drain channels.
3. Ozone treatment breaks down musty and drain odors soaked into ceilings and walls.
4. Your packaging room stops passing a musty smell on to new boxes.
5. It uses CHEMGENE HLD4H, which can be used on a wide range of kitchen surfaces according to the label.
6. It protects the ratings of every brand that cooks in the same kitchen.
7. Kitchen staff work more comfortably without breathing musty air all shift.
8. Downtime is planned around your quietest ordering hours.
9. The team controls the ozone dose and moves or covers electronics before starting.
10. We work regularly in Phra Khanong, On Nut, Bang Chak, and outer Sukhumvit, and you can reach us easily on LINE @whd268.

Before and After

A Kitchen Owner's Perspective

"At first I thought washing the floor would be enough. I never imagined the smell would get into the boxes. When the team came to survey, I understood that I had to throw out the whole batch of packaging, get the grease trap cleaned, and only then do the fogging and ozone. We picked our quietest day to close. When we reopened, the kitchen smelled completely different, and my staff said it was much more pleasant to work in."

May, delivery kitchen owner, On Nut, Phra Khanong (a representative scenario based on typical field situations)

For Shared Commissary Kitchens with Multiple Tenants

Some cloud kitchen operators divide a building into small kitchen units rented by several different restaurants, with a shared corridor, dishwashing area, and pick-up point. If one unit still has mold or a drain smell, the odor spreads through the whole building and every tenant's reviews suffer. Site managers can book our team to fog the shared areas and ozone-treat individual units on the same day, agreeing a common closing slot in advance so every tenant has time to move out their ingredients.

Once recovery is complete, simple house rules make a big difference: no packaging cartons on the floor, floor drains rinsed at the end of every day, and grease traps inspected on a regular schedule. Those habits leave the building far better prepared if heavy rain and sewer backflow return.

It is also worth keeping a small flood kit on site: sandbags or drain covers for the floor gratings, plastic crates to lift stock quickly, and a written list of who to call for electrical, gas, and grease trap work. The faster you can act when water starts rising, the less you will have to throw away afterwards.

Frequently Asked Questions

Q: How long will my kitchen need to close?
A: It depends on the size of the kitchen and the extent of the problem. The team will give you clear fogging, ozone, and ventilation times at the survey, so you can schedule the closure when it affects orders the least.

Q: Do I need to move ingredients out of the freezers?
A: All ingredients and food should be removed or sealed before fogging and ozone treatment. Any food in freezers that lost power for a long time or that was touched by floodwater should be thrown away.

Q: Can we start cooking straight after the fogging?
A: After ventilating for the time the team recommends, wipe or rinse food-contact surfaces according to the label instructions before cooking begins.

Q: Will ozone damage kitchen equipment?
A: The team controls the dose and duration to suit the space, moves or covers electronics, and takes care with rubber seals and parts that can degrade if exposed to high concentrations of ozone for too long.

Q: Can I use boxes that are still sealed in their plastic wrap but were in the flooded room?
A: If the pack was touched by water or feels damp, throw it away. If it sat on a high shelf and is completely dry but smells musty, it is still not worth risking with food.

Q: Which areas do you cover?
A: Phra Khanong, On Nut, Bang Chak, Khlong Toei, Watthana, Bang Na, and nearby areas. Call 065-556-6294.

Let Customers Smell Your Food, Not the Flood

Book a survey for your delivery kitchen, commissary kitchen, or packaging store in Phra Khanong after the floods.

See Our Disinfection Service – Click Here

Book Ozone Treatment – Click Here

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

Related Links

• Ozone odor and chemical residue removal
• CHEMGENE HLD4H disinfectant
• Master Ozone Generator
• All articles
• External sources: WHO: Floods and health and Department of Health, Thailand