A typical scenario (an illustrative situation, not a review from any specific customer)

The pastel-blue room her daughter refused to sleep in

Prae, a mother of two living in a single-storey house in a housing estate near Khlong Chan, had spent the previous year decorating a bedroom for her six-year-old daughter, Khao Hom: cream walls, a shelf of picture books and a bed buried in soft toys. When heavy rain fell day after day at the end of September, water crept into the estate and then into the house until it stood almost half a metre deep. Khao Hom's room, at the back of the house beside a drainage ditch, flooded fastest and stayed wet longest. The mattress was soaked, the plywood wardrobe swelled and split, and a long brown tide line marked the walls.

When the water went down, Prae and her husband rushed to restore the room so their daughter could come home to it. They carried out everything ruined, washed the floor and wiped the walls, and just three days after the water receded a painter they knew repainted the whole room in the pastel blue Khao Hom had asked for. They ordered a new wardrobe, a new mattress and a cartoon foam play mat, and set up the room in a single day. It looked better than before.

On the first night back, Khao Hom complained the room smelled so bad it gave her a headache. She woke in the night with a blocked nose and a cough, and the next evening she refused to go in at all, asking to sleep with her parents. When Prae opened the door, she smelled sharp paint and new-furniture odour, and underneath it a faint damp mustiness. Two weeks later, dark spots and small blisters began to appear under the new paint near the bottom of the walls.

Prae's family is one of many in Bangkok facing something similar. According to news reports, from 24 to 27 September 2026 the city received continuous heavy rain of around 300 mm in roughly 48 hours. On 26 September the Bangkok Metropolitan Administration declared all 50 districts a disaster zone, with eastern Bangkok hit hardest and areas such as Khlong Chan and Bueng Kum mentioned in coverage. Governor Chadchart said the canals were full and drainage would take two to three days after the rain stopped, and Thai media compared the event with the great floods of 2011. As the water receded, many parents made their child's room the first thing to fix, out of love and a wish to bring normal life back quickly.

This article explains why a freshly repainted child's bedroom can keep smelling after a flood, how airborne chemicals affect children, the most common repainting mistakes, and the correct order of work, finished with the ozone paint and chemical-odour removal service from World Health Disinfection (WHD), so your child can breathe easily in their own room again.

Where the smell in a newly painted child's room comes from: three layers of odour

Layer 1: VOCs from paint and repair materials

Wall paint, primer, filler, adhesives and varnish all release volatile organic compounds, or VOCs, while they dry and cure. The water-based acrylic paints used in most homes smell less than oil-based paints, but they still release vapour at first, especially when several coats go on in a closed, air-conditioned room. If the painter cleans brushes with thinner or uses oil-based paint or lacquer on wooden frames, doors and windows, the solvent smell is even stronger.

Layer 2: odour from new furniture and furnishings

Wardrobes and shelves made from particleboard or plywood can release formaldehyde from the glues that bind the wood. New foam mattresses and pillows, foam play mats, new curtains and plastic packaging each give off their own smell at first. When all of these arrive in a small room on the same day, that room suddenly has many sources of vapour at once.

Layer 3: mustiness from moisture trapped under the paint

This is the most dangerous layer and the one most often missed. Brick-and-plaster walls that stood in water for days absorb it deep inside. The surface may look dry within a day or two, but moisture inside can take weeks to escape, depending on wall thickness, humidity and ventilation. Paint applied over a damp wall becomes a lid that traps the moisture. The result is blistering, peeling, white salt deposits and, most importantly, mold growing behind the paint and releasing a musty smell continuously.

Urban floodwater also carries bacteria from sewage, mud and waste. If walls and floors were not thoroughly cleaned and disinfected before painting, that residue gets sealed under the new paint too. International guidance, such as from the CDC, advises cleaning and drying within 24 to 48 hours to limit mold, and discarding porous materials that cannot be cleaned and dried.

Why children are more sensitive to paint fumes than adults

Children are not small adults. Several differences make them more affected by indoor air pollution. First, children breathe faster than adults and, relative to body weight, take in more air, so the same concentration in the air means a larger dose per kilogram. Second, young children spend time close to the floor, sitting, crawling and lying on mats, where some substances and dust settle. Third, their airways, nervous system and immune system are still developing.

Most important is time. Kindergarten and early primary children sleep around ten hours a night or more, and often play or do homework in their room for hours on top of that. A child's bedroom is the room they spend the longest in, so if the air is poor, they are exposed for the longest. After a flood, many families keep rooms shut with the air conditioning on all night to escape the humidity, which allows vapour to build up even more.

Signs parents should watch for

• Headaches, dizziness, or complaints that the room smells too bad to go into
• Blocked or runny nose, sneezing, itchy or red eyes, especially on waking
• Night-time coughing or wheezing; asthma may flare up
• Nausea, poor appetite, drowsiness or unusual crankiness
• Rashes or skin irritation after touching new surfaces or items

If your child has persistent symptoms, difficulty breathing or a fever, see a doctor. If your child waded through floodwater and then develops fever, muscle aches or diarrhoea, tell the doctor about the floodwater contact, because it may relate to waterborne illness such as leptospirosis. An odour-removal service is not medical treatment. Babies, pregnant women, older people and anyone with allergies or lung disease in the household also need extra care.

The impact when your child's room still smells after repainting

Health and sleep

Children sleeping in a room with strong fumes often sleep poorly, wake in the night and get up congested. When sleep suffers, concentration, mood and learning the next day suffer too, right when schools are reopening after the flood.

Money

According to news reports, one Thai business report cited a Chamber of Commerce estimate of about 12,300 million baht in damage from these floods. For a single family, the follow-on costs are furniture, a mattress and paint. If paint went over a damp wall and then blistered and grew mold, you pay again to scrape it off, wait for the wall to dry and repaint. Some homes also have to throw away soft toys that soaked up odour and moisture.

Time and work

When a child will not sleep in their own room, parents do not sleep well either. Many take leave to redo repairs or to take a child with allergy symptoms to the doctor.

Family wellbeing

For a child, a bedroom is a safe place. Seeing it flooded and then turned into a room too smelly to enter can leave a child feeling insecure and anxious whenever it rains. Parents feel guilty that their effort made their child unwell. Giving back a clean, safe room that is easy to breathe in is an important part of the family's emotional recovery.

Home value

Mold marks and blistered paint are the first things buyers and tenants notice. Doing repairs correctly the first time protects the value of the home in the long run.

Common mistakes, and why the usual fixes fall short

1. Painting before the wall is truly dry. This is the number one mistake. Looking at or touching a wall cannot tell you how much moisture is inside. Experienced painters check walls with a moisture meter and wait until readings fall to the level the paint manufacturer recommends.

2. Painting over water stains and mold without cleaning and disinfecting first. Paint is not a disinfectant; covering the problem only hides it for a while.

3. Moving new furniture in straight after painting. This puts multiple vapour sources in one room, and new fabrics, mattresses and soft toys absorb the paint smell.

4. Closing the room and running the air conditioning straight away. An air conditioner recirculates the room's own air rather than bringing in fresh outdoor air, so vapour accumulates instead of being removed.

5. Diffusers, perfume or scented candles. These add another VOC to a child's room and mask the warning sign that the room is not ready.

6. Onions, lemons, coffee grounds or charcoal. They do very little against the vapour coming off every wall, and nothing about moisture under the paint.

7. Relying only on an air purifier. HEPA filters are designed to capture particles such as dust and spores, not gases. Units with carbon filters have limited capacity and need regular replacement. A purifier helps, but it is not the whole answer.

8. Running a cheap ozone generator while the child sleeps. Never do this. Ozone at odour-removal concentrations harms the airways. Ozone treatment must take place in an empty room, with no people, pets or plants, and people may return only after the rest and ventilation period has ended.

WHD ozone paint and chemical-odour removal for children's bedrooms

According to WHD service information, ozone (O₃) treatment breaks down odour molecules at the source rather than masking them. The service targets paint, thinner, epoxy and lacquer odours, VOCs and musty smells, and also helps reduce bacteria, viruses and mold. Afterwards, ozone reverts to oxygen with no residue, and the room is ready to use about two hours after treatment.

What many parents value most is evidence. WHD measures TVOC (total volatile organic compounds) with calibrated instruments before and after treatment, so you can see how the air in your child's room has changed instead of relying on your nose alone. The team uses a Master Ozone Generator and serves homes, condos, offices, factories, construction sites, hotels, storage facilities and automotive clients.

How ozone treatment works for a newly painted child's bedroom

1. Readiness check: walls must have been dry before painting, the paint must have dried for the time the manufacturer specifies, and there should be no mold spots or blisters still needing repair. If there is a moisture problem, the team will advise fixing it first.
2. Baseline TVOC reading: the room is measured for later comparison.
3. Room preparation: children, other family members, pets and plants leave the room and the area around it; windows and doors are closed. The team advises which items should be removed or left in place.
4. Ozone release and contact time: for a duration set by the team according to room size and odour level.
5. Rest and ventilation: after the machine stops, ozone reverts to oxygen and the room is aired. Nobody enters until the team confirms; typically the room is ready about two hours after treatment.
6. Post-treatment TVOC reading: compared with the baseline, with advice on ongoing care.

Safety reminder: ozone treatment is carried out only in an empty, closed room. Children, adults, pets and plants must be out, and may return only after the rest and ventilation period has ended. Ozone comes after washing, drying and repairs; it does not fix damp walls and it does not replace medical care.

10 reasons parents choose ozone after repainting a child's room

1. It cuts paint odour at the source: ozone paint-odour removal oxidises odour molecules instead of adding perfume to a child's room.
2. Several odour sources at once: paint, thinner, lacquer on wooden frames and new-furniture smell.
3. Helps reduce mustiness and germs: it helps reduce bacteria, viruses and mold brought by floodwater.
4. No residue: ozone reverts to oxygen, adding no new chemical to your child's room.
5. Numbers you can trust: calibrated TVOC readings before and after.
6. Your child is back sooner: the room is ready about two hours after treatment.
7. Reaches every corner: under the bed, behind the wardrobe and between shelves, where cloths and purifiers cannot reach.
8. Done by a team with safety procedures: no guessing at dose and timing with a home machine.
9. Can extend to the whole house: if other rooms were repainted or floors recoated, you can plan whole-home chemical-odour treatment.
10. Peace of mind for parents: you know your child's room was handled systematically. Talk to WHD.

Before and after: a child's bedroom transformed

Note: results vary with paint type, drying time, wall moisture and the amount of new furniture in the room.

Example case: a four-year-old's bedroom in Bueng Kum

Example case (a simulated situation to explain the process, not a verified customer review)

Nun lives in a townhome in the Bueng Kum area. Her four-year-old son's bedroom is on the ground floor because he is still small and his grandmother looks after him during the day. Floodwater entered the room to roughly a hand-span deep. After it receded, a painter advised her to wait before repainting, so she began by removing the wet carpet and mattress, washing the floor and walls, disinfecting surfaces, and keeping windows open and fans blowing on the walls every day. The painter checked the walls with a moisture meter and only painted once readings had fallen to a suitable level, using a low-odour water-based paint the shop recommended.

Even with everything done in order, once painting was finished and a new wooden bed and wardrobe were moved in, the smell of paint and furniture was still obvious. Her son, who has a history of allergies, started sneezing in the mornings. Nun contacted the ozone team. They took a TVOC reading, asked everyone in the house, including the cat, to leave the room and the area around it, sealed the room, treated it for the set time, rested and ventilated it, and measured again.

Nun says what reassured her most was seeing the before-and-after numbers and the advice to keep opening the windows every morning for a while. Her son was back in his own room that same week. The lesson: waiting for walls to dry prevents mold under the paint, and ozone deals with the paint and furniture odour left behind after repairs.

Checklist: giving your child a safe bedroom again after a flood

Phase 1: Safety and strip-out

• Have an electrician check sockets and wiring in the flooded room before use, especially low-level sockets
• Wear gloves, boots and a mask while cleaning, and keep children away from the area
• Remove mattresses, carpets, soft toys and porous materials that cannot be cleaned and fully dried

Phase 2: Wash, disinfect and dry

• Wash mud and water stains off walls and floors, then disinfect surfaces with a suitable product such as Chemgene HLD4H at the label dilution and contact time
• Wash plastic toys that were in floodwater first, then disinfect them as the label directs
• Open windows and use fans or a dehumidifier to speed up drying
• Ask the painter to measure wall moisture before deciding to paint

Phase 3: Paint and furnish carefully

• Choose low-odour or low-VOC paint and a primer suited to walls that have been wet
• Ventilate during and after painting, and keep your child in another room until the paint has dried as the manufacturer advises
• Unwrap new furniture and mattresses and air them somewhere well ventilated before bringing them in

Phase 4: Ozone

• Book the team for a baseline TVOC reading
• Everyone, pets and plants out of the room and nearby area; doors and windows closed
• Treat for the set time, rest and ventilate, nobody enters until the team confirms, then take the post-treatment reading

Phase 5: After treatment

• Keep opening the windows every morning for a while, and avoid keeping the room sealed with the AC on 24 hours a day
• Avoid scented candles and diffusers in a child's room
• Check the lower walls weekly; dark spots or blistering may mean moisture still needs fixing
• If your child still has unusual symptoms, see a doctor

Frequently asked questions

1. Can the room be ozone-treated as soon as painting is finished?

Wait until the paint has dried for the time the manufacturer specifies, and make sure the walls have no remaining moisture problem. The team will help assess whether the room is ready.

2. Can my child sleep in the room during treatment?

Absolutely not. The room must be empty of children, adults, pets and plants, and people return only after the team confirms the rest and ventilation period has ended. Never run an ozone machine while anyone is in the room.

3. When can my child go back in?

According to WHD service information, the room is ready about two hours after treatment, subject to the team's confirmation.

4. There is already mold under the paint. Will ozone help?

Ozone helps reduce odour and mold in the air and on surfaces, but if the wall is still damp the mold will come back. Fix the moisture, scrape off blistered paint, clean, let the wall dry, repaint, and then treat for residual odour.

5. What about soft toys?

Items that were in floodwater and cannot be cleaned and fully dried should be thrown away. For items that stayed dry but absorbed paint smell, ask the team whether to remove them or leave them in the room during treatment.

6. The whole house smells musty after the flood. Can everything be done together?

Yes. Ask about residential ozone disinfection alongside paint-odour removal in recently repaired rooms, and the team will plan suitable zones.

Give your child a bedroom they can breathe easily in

Talk to WHD about ozone treatment for paint and chemical odours in children's rooms after the flood, with TVOC readings before and after.

Book paint-odour ozone treatment

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

Related pages

• Ozone paint and chemical-residue odour removal
• Residential and building ozone disinfection
• Chemgene HLD4H medical-grade disinfectant

References

• Wikipedia: 2026 Bangkok floods
• CDC: Floods, cleanup and mold guidance