A story from the field: the classroom Phum would not enter

Teacher Arunee has run a small private learning center for children with special needs in Pak Phli district, Nakhon Nayok, for almost ten years. The center is a wide, single-story building. It has two main classrooms, an occupational therapy room lined with foam mats and fitted with a therapy swing, a small speech practice room and a calm corner with a fabric tent and soft cushions where children can retreat when the world becomes too loud. The children who come here include autistic children, children with ADHD, children with developmental delays and several who also live with asthma.

In early October 2026, days of heavy rain pushed the Nakhon Nayok River and its side canals over their banks and into the fields around the district. Water entered the building to about the height of a hand span and stayed for several days. Teacher Arunee and her assistants lifted almost all the teaching materials and equipment to higher shelves. What they could not save in time were the large foam mats in the therapy room, the rubber safety flooring and the bottom shelves of wooden toys.

When the water went down, everyone pitched in. They shoveled out the mud, scrubbed the floors and poured bleach until the tiles looked clean. But black mold spots still showed on the lower walls, and the therapy room smelled of damp mixed with a strong chlorine note that stung the nose. On the first day they invited parents to bring their children for a short visit, seven-year-old Phum, a boy who is extremely sensitive to smell, stopped at the doorway. He covered his ears and nose, started to cry and refused to step into the room that had always been his favorite. Another child, who has asthma, began coughing within a few minutes of going in.

That night Teacher Arunee sat thinking for a long time. "We cleaned the way any household would clean," she said later. "But our children are not just any children. The musty smell and the chemical smell both stress them. We needed a way to truly disinfect the rooms without leaving behind any smell they would have to endure."

This is a realistic example scenario drawn from the kinds of situations that service teams meet after floods. It is not a news report, but it reflects a challenge many special education teachers in flood-affected districts are facing right now.

Why special education classrooms need extra care after a flood

Many children are highly sensitive to smell and touch

A significant number of autistic children and children with sensory processing differences experience smells far more intensely than adults do. A damp musty smell, the odor of river mud or the sharp scent of bleach, all things an adult might simply put up with, can cause real distress. A child may refuse to enter the room, become anxious or have behavior that is much harder to regulate. Lessons and therapy sessions are interrupted, and the progress that families and teachers have worked hard for can stall.

Health risks after a flood

• Germs in floodwater: Water that has run through fields, drains and animal pens carries bacteria such as E. coli, which settle on floors and toys. Young children who put their hands or objects in their mouths are at higher risk of diarrheal illness.
• Leptospirosis: The bacteria are found in mud and standing water contaminated with rat urine. Adults doing the cleaning should wear rubber boots and gloves, especially if they have any cuts.
• Mold and allergies: Spores released from foam mats, carpets and walls rise into the air when children roll, jump or sit on the floor. This can trigger allergies and asthma, which are not uncommon among children attending special education centers.
• Skin rashes: Children who seek tactile input, who love to lie or roll on mats, can develop itchy rashes from damp, contaminated surfaces.

Parent confidence and continuity of therapy

For children with special needs, weeks away from school or therapy can mean lost skills and broken routines that took months to build. Parents naturally want the center to reopen quickly, but they also worry whether the rooms are truly safe. The center has to strike a careful balance between speed and safety.

A small team with limited time

Most small learning centers have only a handful of staff, and those same teachers are often dealing with flood damage at their own homes. They cannot spend weeks scrubbing every surface, and they should not have to guess which cleaning products are safe for their children. A clear, professional plan takes that burden off their shoulders.

Common methods that do not suit special education rooms

• Strong bleach: It leaves behind a heavy chlorine smell that scent-sensitive children cannot tolerate, and it does not soak into foam mats or rubber flooring where contamination hides.
• Perfume or air freshener sprays: These layer a new smell on top of the old one, creating an extra sensory trigger, and they do not disinfect anything.
• Drying foam mats in the sun only: The outer skin dries, but the core stays damp and smelly. Mold can return within days.
• Running fans all day: Fans help drying, but they also lift mold spores into the air of a room that children will soon be breathing.
• Rushing to repaint: Fresh paint smells strongly, which disturbs children, and if the wall is still damp, mold will push the paint into blisters again.

The key lesson is that a special education classroom does not just need to look clean. It needs to be truly clean, with nothing left behind to smell, before children come back.

The solution: scent-aware disinfection fogging and ozone treatment by WHD

The World Health Disinfection (WHD) team uses two complementary steps. The first is a disinfection fogging service using Chemgene HLD4H applied with a ULV (ultra-low volume) fogger, so that fine droplets reach floors, lower walls, the gaps between toy shelves and every surface children touch. The second is an ozone treatment service. Ozone is a gas that spreads through the whole room, reducing mold spores and breaking down musty odor molecules instead of masking them with perfume. Once the room has been ventilated for the required time, ozone breaks back down into oxygen, so no perfume or strong chemical smell is left in the classroom.

Step-by-step process for special education centers

1. Survey with the lead teacher: The team walks through every room with the teacher who knows the children best: classrooms, the therapy room, speech room, calm corner, toilets and kitchen. They record the water level, mold spots and any teaching aids or therapy equipment that need protection.
2. Advice on sorting and mud removal: The team helps decide which foam mats or carpets were soaked for too long to keep, and asks that mud be washed off surfaces first so the disinfectant can work at full strength.
3. Moving or covering sensitive items: Communication tablets, speakers, soft rubber toys, therapy balls and children's artwork should be removed or tightly covered. Ozone is used at a controlled dose, but electronics and rubber parts still deserve extra protection.
4. ULV disinfection fogging: The disinfectant is fogged across floors, lower walls, toy shelves, tables, chairs, handrails, toilets and shared touchpoints.
5. Closed-room ozone treatment: Doors and windows are closed and the generator runs for a period matched to the room size. During this time no children, teachers, pets or plants may be inside.
6. Longer-than-usual ventilation: For centers with scent-sensitive children, the team recommends allowing extra ventilation time. A common plan is to treat on Friday evening or Saturday, then leave the rooms open and airing throughout Sunday before children return on Monday.
7. Joint re-check with teachers: The teacher who knows the children best walks the rooms with the team to check for any lingering smell. If any spot still smells, it is assessed and dealt with before the room reopens.

Ozone safety: Ozone is very effective against mold and odor, but it must not be inhaled at high concentrations. The team cordons off the area, posts no-entry signs and ventilates until the rooms are safe before teachers go back in. Children return only after teachers have confirmed that the room feels fresh and free of disturbing smells.

Helping children return to a familiar room

Many teachers use social stories, short picture-based explanations, to tell children in advance that the room has been cleaned and that some things might look a little different. They then bring children back gradually, perhaps for a short visit first, then a short lesson, then a full day. A room that has no strange new smell makes this adjustment far easier.

Clear, honest communication with parents

Parents of children with special needs often ask detailed questions: which product will be used, when the rooms will be safe and when their child can return. The center can share the service steps in advance, explain when rooms will be closed for fogging and ozone treatment and how much time has been set aside for ventilation. Clear information reduces anxiety and helps parents prepare their children at home. Some centers invite parents to see the rooms before reopening day so they can confirm for themselves that the space feels fresh and comfortable.

Thinking about the therapy room

The occupational therapy room deserves special attention because children use it with their whole bodies. They lie on mats, swing, crawl through tunnels and press their faces into cushions. Anything that stays in this room after the flood should be either cleaned and disinfected thoroughly or replaced. Removable covers can be washed. Solid equipment such as climbing frames and swing hooks can be wiped and included in the fogging. Foam that was soaked through is usually better replaced, because moisture deep inside it is very hard to remove.

Where mold hides in a special education classroom

Mold does not only grow where you can see it. In a learning center, there are several places that teachers tend to overlook during the first clean-up, and they are often the source of the smell that just will not leave.

• Under and inside foam mats: Water seeps through seams and is trapped in the foam. The top may look dry while the underside is already speckled with mold.
• Behind and under low shelves: Toy shelves and cubby units sit close to the wall, so air cannot circulate. The back panels, often made of particleboard, swell and grow mold quickly.
• Fabric tents and calm corners: Soft furnishings in calm corners absorb damp air even if they were never under water. They often smell musty within a week.
• Skirting boards and door frames: Wood and plywood trim soak up water from the floor and hold it for weeks.
• Air-conditioner filters and drain pans: High humidity after a flood encourages growth inside air-conditioning units, which then blow spores around the room. Ask an air-conditioning technician to clean the units before the room reopens.
• Bathroom and changing areas: Many special education centers have changing tables and accessible bathrooms. Grout, the underside of changing mats and the base of toilets need careful attention.

The WHD survey checks these spots specifically, so that fogging and ozone treatment are planned to reach them and so you know which items need cleaning, drying or replacing before treatment.

The first 72 hours: what your team can safely do

A professional service works best when the center has done some basic preparation. These steps are simple and can be done by staff and volunteers while waiting for the survey.

1. Keep children away: Do not bring children into the building until the mud has been removed and the rooms have been disinfected. Even a short visit can expose them to contaminated surfaces and strong smells.
2. Protect yourselves: Wear rubber boots, long gloves and a mask when handling mud, and cover any cuts carefully because of the leptospirosis risk.
3. Photograph damage: Take pictures of water lines and damaged equipment before moving anything. These are useful for insurance and for planning replacements.
4. Remove mud while it is soft: Dried mud turns into fine dust that carries germs into the air.
5. Separate and dry what you want to keep: Spread out books, picture cards and visual schedules in a dry, ventilated room rather than leaving them stacked.
6. Go easy on chemicals: Use plain detergent and water for the first wash. Avoid mixing cleaning products, and avoid using strong bleach in closed rooms that children will soon use.
7. Check electricity: Ask a qualified electrician to inspect sockets and wiring at floor level before turning the power back on.

Planning a calm reopening week

Reopening is not a single moment, it is a process. Many centers find it helpful to plan the first week carefully. Start with shorter days and smaller groups so teachers can watch how each child responds to the room. Keep the timetable as close as possible to the usual routine, because predictability helps children feel safe. Put back familiar items such as a favorite cushion cover or a visual schedule as soon as they are clean and dry. And keep a simple log of any coughing, sneezing, skin irritation or signs of distress, so you can quickly spot a room or an item that still needs attention. If the log shows a pattern, the WHD team can come back to re-check that area.

10 reasons special education centers in Pak Phli trust WHD

1. Work is planned around scent-sensitive children, with no perfume used to cover odors.
2. Chemgene HLD4H disinfectant is designed for high-level disinfection and suits surfaces children touch every day.
3. ULV foggers reach the gaps between toy shelves and corners that are hard to wipe.
4. Ozone treatment reduces musty odor in mats, carpets and calm corners, then breaks down into oxygen after ventilation.
5. Scheduling outside school hours, with extra ventilation time before children return.
6. Clear steps to protect tablets, speakers, rubber toys and children's artwork.
7. Honest advice on which mats or carpets to keep and which to replace.
8. Follow-on dust mite removal service for pillows and cushions you decide to keep.
9. Chemgene HLD4H spray (750 ml) for teachers to wipe touchpoints during the day.
10. Easy to reach by phone and LINE, with advice before you book.

Before and after disinfection and ozone treatment

Customer voice (example scenario)

"The only thing we asked the team was to leave no smell behind. They scheduled the work for Friday evening, asked us to move the rubber toys and tablets out first, and then we left the rooms open all Sunday. On Monday, Phum walked into the room by himself. The teachers could hardly believe it."

— Teacher Arunee, founder of a special needs learning center in Pak Phli (example scenario)

Aftercare checklist for special education classrooms

• Open windows every morning before children arrive, and run a dehumidifier in any room that still feels stuffy.
• Wash plastic toys in soapy water, then wipe with disinfectant and let them dry fully before returning them to the shelf.
• Wash cushion covers, pillows and calm-corner fabrics in hot water where the care label allows, and dry them completely.
• Avoid air fresheners, incense and scented candles in classrooms.
• Wait until walls are completely dry before painting, and plan painting for a school break or long weekend.
• Watch for coughing, sneezing or rashes in children, and for any returning musty smell, during the first two to four weeks. If you notice anything, ask the team for a re-assessment.

Frequently asked questions

Q: Will there be any smell left after ozone treatment?
A: During treatment there may be a smell similar to the air after a thunderstorm. After full ventilation, ozone breaks down into oxygen. For centers with scent-sensitive children, the team recommends allowing extra ventilation time before children return.

Q: When can children come back?
A: After the rooms have been ventilated until safe and teachers have checked that there is no disturbing smell. Many centers schedule the work for Friday evening or Saturday and reopen on Monday.

Q: What should we do with rubber toys and therapy balls?
A: Remove them from the room during ozone treatment, then wash them in soapy water and wipe them with disinfectant separately to protect the rubber.

Q: Should we keep foam mats that were under water?
A: If they were soaked for a long time and smell from the inside, they are usually not worth keeping. The team can help you assess them one by one.

Q: Does this service replace medical advice?
A: No. WHD services care for the environment. If a child shows unusual symptoms, please consult a doctor.

Q: Can you treat only one room so the rest of the center stays open?
A: Yes. The team can work zone by zone. Treated rooms are sealed off and ventilated while other parts of the building remain in use, as long as the treatment area is clearly closed and nobody, especially children, can wander in. For small centers, however, treating the whole building over one weekend is often simpler and less disruptive for the children's routine.

Q: Which areas do you serve?
A: Pak Phli, Mueang Nakhon Nayok, Ban Na, Ongkharak and nearby parts of Prachin Buri. Ask us on LINE @whd268.

Make the classroom a safe place for every child again

Book a site survey for your special education center in Pak Phli and Nakhon Nayok.

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View Disinfection Service – Click Here

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

Related links

• Residential ozone disinfection
• Ozone treatment for odor and chemical residue
• Dust mite removal service
• All articles

Health reference: World Health Organization (WHO): Floods · Department of Health, Thailand