What happened in Bangkok in late September 2026

According to news reports, Bangkok received roughly 300 mm of rain in about 48 hours between 24 and 27 September 2026, flooding large parts of the city. On 26 September the Bangkok Metropolitan Administration declared all 50 districts a disaster zone. Eastern Bangkok was hit hardest, with Khlong Chan and Bueng Kum among the areas mentioned. Governor Chadchart said the canals were full and drainage would take two to three days after the rain stopped.

Reports noted three deaths, and we offer our sincere condolences to their families. As of 30 September, some roads such as Si Burapha and Lat Phrao still had 20 to 40 cm of water. Thai media compared the event with the 2011 floods, and one Thai business report cited a Chamber of Commerce estimate of about 12,300 million baht in damage.

For elderly day care centres, the flood did not only damage buildings. It disrupted the daily routine of every family that relies on the centre to look after a parent while they work. As soon as the water dropped, sons and daughters had to return to their jobs and began asking when the centre would reopen. But a centre responsible for some of the most vulnerable people in the city can only open its doors when it is confident every room is genuinely clean and safe.

A typical scenario (an illustrative situation based on common post-flood experiences, not a review from a specific customer)

The phone that would not stop ringing

Nid spent almost twenty years as a nurse in a public hospital before opening a day care centre for older adults in a two-unit townhouse in eastern Bangkok. Every morning around twenty seniors are dropped off by family members on their way to work. Some walk on their own, some use canes or walkers, some use wheelchairs, and several are in the early stages of dementia.

The ground floor is an activity room with comfortable upholstered chairs arranged in a circle. One corner is a physiotherapy area with rubber floor mats and a walking rail. Beyond that is a bathroom with grab bars and a small kitchen that prepares soft food. Upstairs is a rest room with folding beds and mattresses for afternoon naps.

On the night of the heaviest rain, water in the lane kept rising until it entered the ground floor to about a hand's span deep. Nid and her assistant carried what they could upstairs, but the upholstered chairs, physio mats and a cabinet of adult diapers sat in water for days.

When the water receded, her phone rang constantly. One daughter had to return to her factory shift. One son, a salesman, could not take any more leave. Everyone asked the same question: "When will you reopen?" Nid understood every family's situation. But as a former ward nurse, she also knew that opening too early, into rooms that still smelled musty, with mold hidden in cushions and flood residue in corners, could make frail seniors seriously ill. The question she had to answer first was: "What exactly needs to be done, and in what order, so I can welcome everyone back with confidence?"

Why day care centres carry more risk than ordinary buildings

Urban floodwater mixes with canal water, drain overflow and, in places, sewage. Health agencies such as the US CDC, Thailand's Department of Disease Control and the Department of Health warn that it can carry faecal bacteria, diarrhoea-causing viruses and leptospirosis bacteria. When the water drains away, these germs remain in mud, silt and absorbent materials. Lingering moisture then allows mold to grow within days, which is why the WHO and CDC advise cleaning and drying buildings within 24 to 48 hours after floodwater recedes.

Older bodies cope less well with infection

The immune system slows with age, and many older adults live with diabetes, high blood pressure, heart disease, kidney disease or chronic obstructive lung disease. An infection that a younger adult shakes off in a few days can develop into pneumonia or serious dehydration in an older person. A few bouts of diarrhoea can upset electrolyte balance, and anyone with a diabetic foot wound faces a higher chance of infection from a contaminated floor.

Many cannot describe their own symptoms

Seniors living with dementia may be unable to say that breathing feels harder, their eyes itch or their stomach hurts. Caregivers have to read changes in behaviour, such as more coughing, drowsiness, eating less or unusual irritability. That means the centre must prevent problems as far as possible rather than wait for symptoms to appear.

Caregivers are part of the risk picture too

Staff at small centres often lived through the same flood at home. Many waded through water to reach work or to help neighbours, and they spend the day in close contact with seniors: helping them to the toilet, feeding them and supporting them as they walk. A caregiver who picks up a stomach bug or a skin infection can pass it on without meaning to. Protecting staff with gloves, boots, handwashing and a clean workplace is therefore also a way of protecting the seniors in their care.

Risk points specific to a day care centre

Upholstered chairs and sofas. These are where seniors sit most of the day. The foam inside holds a lot of water and dries slowly, and after a flood it often becomes a hidden mold source.

Nap mattresses and pillows. During afternoon rest, faces press against pillows and cushions. In a damp room, mold spores and dust mites build up in the fabric.

Wheelchairs, walkers and canes. Wheels and feet that touch contaminated floors carry germs around the centre, while handles are gripped constantly.

Bathrooms and grab bars. The most-used room, and the highest risk if drains backed up with wastewater during the flood.

Physiotherapy mats and equipment. Rubber mats, hand balls and walking rails sit at floor level and touch skin directly.

The soft-food kitchen. Seniors with swallowing difficulties eat blended or soft meals, which are easily contaminated if boards, utensils and blenders are not properly washed and sanitised.

Air conditioners. Most centres run air conditioning all day. If coils and drip trays stay damp, the unit spreads spores and musty smells across the room every time it switches on.

The cost of reopening too early, or too late

Health. Reopening while mold and musty air remain can trigger flare-ups in seniors with lung disease or allergies. If surfaces still carry flood germs, a single stomach infection can spread, because everyone shares the same bathroom and activity room.

Money. Small centres earn daily or monthly fees. Every closed day is lost income while rent, wages and repair bills continue. Reopening early, then closing again because seniors fall ill, costs far more than staying closed a few extra days to do things properly.

Time. Repairs done out of order, such as painting before walls dry or laying new mats on a damp floor, usually have to be redone.

Reputation and trust. Elderly care depends on family trust. If relatives smell damp at pick-up or a parent comes home coughing, years of goodwill can disappear in a week, and news travels fast in community chat groups.

Families. On the other hand, if the centre stays closed for too long with no clear plan, relatives must take unpaid leave or leave seniors alone at home in houses that were also flooded. A clear recovery plan with a realistic reopening date helps everyone.

Why rushed cleaning is not enough for a senior centre

Wiping everything with bleach. Properly diluted bleach does sanitise cleaned hard surfaces. But chlorine fumes in a closed room can irritate seniors with lung conditions, it cannot be used on upholstered chairs or cushions, and it does nothing for germs in the air.

Running air conditioning and fans day and night. This lowers humidity somewhat, but if mold is already present the airflow spreads spores, and an air conditioner with damp coils pushes musty air back into the room each time it runs.

Air freshener or essential oils. The room smells nicer, but the source is only masked, and strong scents can trigger allergies or make some seniors dizzy.

Buying a small ozone machine and running it with people inside. This is a dangerous misunderstanding. Ozone strong enough to disinfect must only be used in empty rooms. Running a generator while seniors are present can irritate the airways, which older people tolerate far less than others.

Painting over mold. It makes a room look new for opening day, but if the wall is still damp inside, the stains return and fresh paint smell becomes a second problem that may need ozone chemical-residue removal as well.

Each of these quick fixes helps a little, but none treats the air, the corners and the many surfaces of a centre at once without leaving chemicals behind in rooms where seniors breathe all day.

How ozone disinfection works for elderly day care centres

Ozone (O₃) is a strongly oxidising gas. Released at a controlled concentration in a sealed room, it spreads through the air, under beds, behind cabinets, into chair seams and through air-conditioner vents. It breaks down the cell structures of viruses, bacteria and mold, along with the molecules that cause musty odours, then reverts to oxygen (O₂). No chemical residue is left on cushions, pillows or dining tables.

According to the test results certified for the company, World Health Disinfection's service has been tested by Thailand's Department of Medical Sciences and Intertek UK, eliminating viruses, bacteria and mold by 99.99%. The team serves homes, condos, hotels, offices, schools and hospitals, so it is used to working in spaces that care for vulnerable people.

Safety rules a senior centre must apply strictly

The room must always be empty. No seniors, caregivers, pets or plants inside during treatment, and nobody re-enters until the technicians confirm the rest and ventilation period is over. Schedule treatment on a closed day or after hours, so there is plenty of time to air the rooms before seniors return.

Clean and dry first. Ozone does not replace mud removal, floor washing, laundering or drying cushions, and it cannot make soaked foam safe again. Cushions or chairs that sat in contaminated water and cannot be dried completely should be replaced. Ozone is the final step once the space is clean and dry.

It is not medical treatment. Any senior or caregiver with fever, worsening cough, breathlessness, diarrhoea or calf pain after wading through floodwater must see a doctor promptly.

The service process

1. Site survey and planning with the owner. Technicians assess the activity room, rest room, bathrooms, physio area, kitchen and storage, and agree a closed day for treatment.
2. Zoning by use, so each room receives the right concentration and duration.
3. Room preparation. Close doors and windows, switch off air conditioning as advised, open cabinets and drawers, unfold beds so gas can circulate, and move medicines and supplies as the team recommends.
4. Ozone release in the sealed room, typically about 30 minutes per zone depending on size and conditions.
5. Rest and ventilation, letting ozone revert to oxygen before doors and windows are opened.
6. Handover, with advice on humidity control and daily care of frequent touch points after reopening.

For ozone jobs of 15,000 baht or more, you receive a free medical-grade disinfectant spray, handy for wiping wheelchair handles, grab bars and door handles every day. See the residential and building ozone disinfection service for details.

10 reasons an elderly day care centre should use ozone before reopening

1. No chemicals left in rooms where seniors breathe all day. Ozone reverts to oxygen after the rest period.
2. Reaches foam and seams in upholstered chairs that cloths and sprays cannot.
3. Reduces airborne germs in the nap room, where seniors sleep close to pillows and cushions. See how it works on the ozone disinfection service page.
4. Tackles musty odour at its source instead of masking it with fragrance that can trigger allergies.
5. Covers bathrooms, physio area and kitchen in one visit when zones are planned properly.
6. Helps reduce the risk of group spread, since seniors share spaces all day.
7. About 30 minutes per zone, so it fits into a closed day without extending the shutdown.
8. Backed by testing, according to results certified for the company by the Department of Medical Sciences and Intertek UK.
9. Gives owners a clear story for families: every recovery step was completed before reopening.
10. Ongoing care advice included. Ask questions or book through the WHD ozone service.

Before and after a systematic recovery

Example case: a five-day plan before reopening

This example case is a hypothetical scenario used to explain the process. It is not a review or quote from a real customer.

Nid messaged every family in the centre's chat group: the centre would reopen in five days, with a short plan for each day. Being direct helped relatives arrange leave or temporary care, and most replied with understanding.

Days one and two. Wearing gloves, boots and masks, Nid and her assistant removed mud and washed the ground floor with clean water and detergent. An electrician checked the flooded sockets before power was restored. Three upholstered chairs with sodden foam were thrown away; the rest were cleaned and sun-dried. Curtains, sheets and pillowcases were washed in hot water.

Day three. A technician cleaned every air conditioner, replaced filters and cleared drain lines. Physio mats were washed one by one, wheelchair wheels and walker feet were scrubbed, and the kitchen washed every board, utensil and blender while discarding any food that might have touched floodwater.

Day four. The ozone team worked while the building was empty, treating the activity room, physio area, bathroom, kitchen and upstairs rest room as separate sealed zones with no people, pets or plants inside. After contact time and rest, the team opened doors and windows and advised keeping them open until the next morning.

Day five. Nid walked through every room, wiped handles, rails and dining tables with disinfectant spray, placed a humidity meter in the activity room and prepared a daily symptom-observation sheet for the first two weeks.

On reopening morning, relatives did not see a fancier centre. They saw clean rooms, fresh air and a clear explanation of what had been done. In a case like this, that builds more trust than any advertisement could.

Reopening checklist for elderly day care after a flood

Building safety

• Have an electrician inspect any sockets, wiring and breakers that were underwater.
• Check for slippery floors, loose grab bars and damaged wheelchair ramps.
• Inspect gas cylinders and kitchen appliances.

Cleaning and drying

• Remove mud and wash floors and lower walls with clean water and detergent.
• Discard cushions, foam and mattresses soaked in contaminated water that cannot be dried.
• Hot-wash all curtains, sheets, pillowcases and towels.
• Clean wheelchairs, walkers, canes and physio equipment.
• Service air conditioners and drain lines; replace filters.
• Discard food, medicines and medical supplies touched by floodwater, and restock medicines with families.
• Ventilate and use a dehumidifier if available.

Treatment day and after

• Schedule ozone on a closed day with no seniors, staff, pets or plants inside.
• Post "do not enter" signs and lock doors during treatment.
• Re-enter only when technicians confirm rest and ventilation are complete.
• Wipe frequent touch points daily after reopening.
• Observe seniors daily. If anyone shows fever, cough, drowsiness, diarrhoea or breathlessness, inform the family and arrange a doctor's visit.

Frequently asked questions

Is ozone dangerous for seniors?

Ozone at disinfecting concentrations irritates the airways, which is why treatment happens only in empty rooms. Seniors return only after the rest and ventilation period, by which time the ozone has reverted to oxygen. We recommend treating at least a day before reopening so rooms can be aired fully.

Can we run a home ozone machine while seniors are present?

No. Running any ozone generator in an occupied room risks lung irritation, especially for seniors with lung disease or asthma. Treatment should be done by experienced technicians who control timing and concentration.

Can flooded upholstered chairs be saved with ozone?

It depends on how long they were submerged and whether the foam can be dried completely. If they sat in contaminated water and are still damp inside, replace them. Ozone reduces germs and odour in clean, dry materials but does not make wet materials safe.

Do medicines and medical supplies need to be moved?

Anything touched by floodwater should be discarded. For unaffected medicines, the team will advise on storage during treatment; sealed boxes or temporary removal are the simplest options.

How long must the centre close?

Treatment typically takes about 30 minutes per zone plus preparation, rest and ventilation, so a small centre is usually done in a day. The total closure depends mostly on mud removal, washing and drying, which must come first.

Should we tell families that the centre was treated?

Yes. A short message explaining what was cleaned, what was replaced, when ozone treatment took place and what daily measures will continue helps relatives feel informed. Keep it factual and invite them to ask questions or visit before drop-off.

After ozone, do we still need daily cleaning?

Yes. Ozone resets the space after a flood, but wiping touch points, handwashing and humidity control remain daily routines in any senior care setting.

Reopen with confidence for the seniors families trust you with

Talk to our team about zone-by-zone ozone disinfection on a closed day, with full ventilation time before reopening.

Book Ozone Disinfection

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

Related services and reading

• Residential and building ozone disinfection
• Ozone removal of chemical residue after painting or new furniture
• Chemgene HLD4H medical-grade disinfectant
• Certificates and test results
• Contact World Health Disinfection

References

• 2026 Bangkok floods – Wikipedia
• Al Jazeera: Disaster zone declared across Bangkok
• CDC – Floods and cleanup
• Department of Health, Thailand