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

A garage where paint smell was normal, until this time

Lek has run a repair and paint shop down a soi on the eastern side of Bangkok for almost twenty years. He has two vehicle lifts, a small paint-mixing room at the back, a self-built spray booth, and a corner where drums of used engine oil wait to be sold on. For a painter, thinner and auto paint smells are so familiar he barely notices them. But after the continuous heavy rain of 24 to 27 September 2026, the garage smelled so different that even his veteran mechanics covered their noses.

Water stood almost half a metre deep inside for several days. Used-oil drums on the floor tipped over and floated against the wall, spreading a slick across the surface. Primer tins and thinner cans in the mixing room fell everywhere. The spray-booth filters were soaked, cardboard parts boxes collapsed, and three customer cars waiting for repair sat in water up to half their wheels. When the water went down, the entire floor was covered in black mud laced with oil, and the air carried a blend of old engine oil, solvent, auto paint and the rotten-mud smell of drain water.

Two workers shovelling mud complained of headaches within the first hour. Customers phoning to ask when the shop would reopen got only "not sure yet". Lek knew reopening was not just about getting the tools working. The workplace had to be safe enough for his team and the air good enough that customers would be willing to sit and wait for their cars.

According to news reports, around 300 mm of rain fell in about 48 hours, the Bangkok Metropolitan Administration declared all 50 districts a disaster zone on 26 September 2026, and the east of the city, including areas around Bueng Kum and Khlong Chan, was hit hardest. Thai media compared the event with the 2011 floods. For the vehicle repair trade, this is the moment when the garage itself needs restoring while a queue of flood-damaged customer cars waits outside.

Why garages and paint shops have the worst chemical odours after a flood

A repair shop concentrates petroleum products and several chemical groups in one place, mostly at floor level for convenience. When floodwater enters, they meet it directly.

Oils and vehicle fluids

New and used engine oil, gear oil, brake fluid, coolant, grease and fuel drained from tanks. Most do not dissolve in water, so they float as a film and stick to floors, walls, lift posts and tools. When the water falls, oil soaks into porous concrete and keeps releasing odour, especially in hot weather.

Paints and solvents

Paint shops use primer, base coat, clear coat, gun-wash thinner, body filler and hardeners. These are major VOC sources. When containers fall or leak in water, the products spread and lodge in absorbent materials such as rags, masking paper and booth filters.

Batteries and corrosives

Batteries stored on the floor that were submerged may leak. Handle them carefully with gloves and eye protection, never bare-handed, and send them for proper disposal rather than into general waste.

Cleaning and degreasing products

Many garages stock degreasers, engine-bay cleaners and interior cleaners in bulk. Mixed into floodwater, they add another layer of chemical smell.

Mud and sewage

Urban floodwater brings sediment and drain water. Mixed with oil, it becomes a sticky black sludge that is hard to wash off and smells of decay on top of petroleum. Left damp, it grows mold and bacteria.

Flooded customer cars

Cars that flooded in the garage, and those customers bring in after the water drops, often have soaked carpets, seats, seat foam and under-carpet insulation. The cabins smell intensely musty, and with several parked inside at once, their odour joins the garage's own.

Three places in a garage where odour sinks deepest

1. The mixing room and spray booth

Both are usually enclosed to control dust. When flooded, vapours from leaked thinner and paint build up inside, and soaked ceiling and floor filters absorb both muddy water and chemicals. Afterwards every filter needs replacing, the room washing, and the extraction fans checking before any painting resumes.

2. The pit or floor under the lifts

The area under the lifts and the workshop drainage channels already collect oil in normal times. Floodwater lifts years of old residue and spreads it around. Afterwards, the oil interceptor and drains are often packed with oily sludge, the strongest-smelling spot in the building.

3. The customer lounge and office

Many garages have a small air-conditioned room where customers wait, with a sofa, carpet, curtains and paperwork. These absorb garage odour easily, and it is the first space customers experience. If it smells musty and oily, they sense straight away that the shop is not ready.

Health risks for mechanics and customers

Mechanics and painters work with chemicals routinely and should always use suitable protective equipment. The post-flood situation is different, though: vapours are no longer coming from controlled work inside a booth but evaporating from floors, walls and materials throughout the garage all day.

• From solvent and oil vapours: headache, dizziness, nausea, stinging eyes and nose, fatigue.
• Respiratory symptoms: cough, sore throat and breathlessness, especially in people with asthma or allergies.
• Skin: prolonged contact with oily mud and solvents causes dry, cracked or irritated skin and rashes.
• Flood-borne disease: wading through water and mud carries a risk of leptospirosis, skin infections and diarrhoeal illness.

Who should take extra care

Mechanics with asthma, lung or heart disease, pregnant employees, customers waiting with small children or older relatives, and the owner's family, who often live upstairs in the same building, should avoid areas that still smell strongly.

Electricity comes first

Garages run heavy electrical loads: lifts, compressors, welders. News reports noted that one of the deaths in this flood was an electrocution in a car park, so an electrician must inspect and isolate flooded circuits before any clean-up starts. Our condolences to the families who lost loved ones.

Anyone who develops fever, calf pain, red eyes, diarrhoea or breathing difficulty, or whose symptoms worsen after working in the garage, should see a doctor promptly and mention flood and chemical exposure. Odour removal is not medical treatment.

What a lingering smell does to a garage business

Lost revenue just when demand peaks

After a flood, many cars need electrical, engine and interior work. This is when a garage should be busiest. If yours is not ready, customers go elsewhere and may never come back.

Paint quality suffers

A booth that is still damp, dusty with dried mud or fitted with old filters directly affects the finish: dust nibs, uneven surfaces, adhesion problems. Rework means extra cost and a damaged reputation.

Finished cars that smell of the garage

Cars parked in a garage still thick with oil and thinner vapour can absorb it into the cabin, especially fabric seats and carpets. A customer who drives off and smells chemicals will be unhappy even if the repair is perfect.

Staff sick leave and turnover

Skilled mechanics are hard to find. Facing a headache every day, they may take sick leave or move to a shop that recovered faster.

Stacked financial pressure

One Thai business report cited a Chamber of Commerce estimate of about 12,300 million baht in damage from this flood. For a small garage, damaged tools, parts and paint stock plus lost income while closed add up to a heavy burden, which makes a fast, safe reopening all the more important.

Why the usual garage fixes do not get rid of the smell

Pressure-washing alone

A pressure washer shifts mud well, but plain water does not dissolve oil and can push it into floor joints or drains. Use a suitable degreaser according to its label and handle oily wastewater properly.

Cleaning the floor with thinner

Some mechanics are used to wiping stains with thinner, but washing an entire floor with solvent puts a large extra load of vapour into the air and raises the fire risk while the electrics are still unchecked.

Running the booth fans and calling it done

Booth extraction is designed to capture overspray during painting, not to remove odour embedded in walls, floors and surrounding materials. If the motor was submerged, it also needs inspecting before use.

Repainting the garage straight away

Fresh wall paint or epoxy flooring is a common post-flood upgrade, but applied over damp or oily surfaces it will not bond, and it adds another batch of VOCs to a building still carrying the old smell.

Air freshener in the customer lounge

Fragrance masks for a while, but with oil and thinner still drifting in from the workshop, the perfume-plus-chemical mix can feel worse to customers than either alone.

The answer for garages: WHD ozone chemical residue and odour removal

Once the garage has been cleared, degreased, re-filtered and dried, the finishing step is the ozone chemical residue and odour removal service from World Health Disinfection (WHD). According to the service information, ozone (O3) breaks odour molecules down at the source instead of masking them, handles paint, thinner, lacquer and epoxy odours, VOCs and mustiness, helps reduce bacteria, viruses and mold, then reverts to oxygen with no residue. The service also covers the automotive sector.

The workshop and the car cabin

For the building, the team plans treatment zone by zone: mixing room, spray booth, workshop floor and customer lounge, using the Master Ozone Generator sized to the real volume. For flooded customer cars, once damaged carpet, seats or insulation have been removed and the interior washed and dried, treating the cabin helps reduce residual mustiness. Nobody may be inside the vehicle during treatment.

TVOC figures to show staff and customers

According to the service information, WHD measures TVOC with calibrated instruments before and after treatment. A garage can use those numbers to reassure its mechanics that the workplace is safer and to show customers that recovery was handled systematically.

How the service runs in a garage

1. Survey. Confirm damaged oil drums, paint, thinner and batteries have been removed, remaining containers are sealed, and the electrics have been checked.
2. Baseline TVOC in the mixing room, spray booth, under the lifts and in the customer lounge.
3. Preparation. Mechanics, customers, pets and plants leave every zone to be treated; roller doors and openings are closed.
4. Ozone treatment with the Master Ozone Generator in the empty, closed space for the appropriate time.
5. Rest and ventilation. According to the service information, the space is ready to use about two hours after treatment.
6. Follow-up TVOC, compared with the baseline, with advice on any spots that need more work.

Safety first: ozone treatment is done only in an empty, closed space. People, pets and plants must be out and may return only after the rest and ventilation period. Do not treat an area with open containers of flammable liquids. Ozone follows mud removal, washing and drying; it does not replace cleaning, painters' personal protective equipment, spray-booth ventilation, or medical care.

10 reasons garages and paint shops use ozone after a flood

1. Breaks down thinner, paint and lacquer odours at the source, as described on the ozone chemical-odour service page.
2. Tackles mud and sewage mustiness layered with oil smell in the same pass.
3. Reaches the mixing room and booth, with their many corners and gaps behind shelving.
4. Leaves no residue on surfaces you will paint, because ozone reverts to oxygen.
5. Helps reduce mold and bacteria in a customer lounge with sofas and carpet.
6. Works for flooded car cabins once damaged materials are out and the interior is dry; the service covers automotive work.
7. Before-and-after TVOC for transparent communication with staff and customers.
8. Fast reopening: about two hours after treatment. See the WHD service details.
9. Supports renovation: after new wall paint or epoxy flooring, treat again to reduce new-material odour.
10. A professional image: customers walk in and sense the shop is ready. Talk to the team.

Before and after: a garage restored in the right order

Example case: a small car paint shop in eastern Bangkok

Example case (an illustrative scenario explaining the process, not a specific customer's testimonial)

Tor runs a body and paint shop working on sedans and pickups, with one spray booth, a small mixing room and an air-conditioned customer lounge. In late September 2026 his shop stood in knee-deep water for several days. Afterwards he found two leaking thinner cans, several rusted primer tins, booth floor filters full of mud and a lounge sofa so wet it had to go.

He began by having an electrician check everything, including the booth fan motor and the compressor. His team, in chemical-resistant gloves, boots and suitable masks, moved the leaking thinner and paint containers to an open area and called a licensed waste contractor. They shovelled out the mud, washed the floor with a degreaser used according to its label, cleaned the oil interceptor, replaced every ceiling and floor filter in the booth, then opened the doors and ran fans to dry the space.

Once dry, the mixing room and lounge still smelled of thinner and damp. Tor contacted WHD. The team measured TVOC at several points, had everyone leave, closed the roller doors, treated zone by zone with a Master Ozone Generator, rested and ventilated the space, then measured again. Tor says his team felt noticeably more comfortable and the lounge was fit to welcome customers again. He later had the team treat the cabin of a customer's flooded pickup, after the shop had stripped out the ruined carpet and insulation and dried the interior.

The lesson: in a garage, start with the electrics, then handle chemicals and oil residue properly, and use ozone as the finishing step for the odour left behind.

Garage and paint shop flood recovery checklist

Safety before work starts

• Have an electrician inspect and isolate flooded circuits, including lifts, compressors and welders.
• No smoking, welding, grinding or open flames until you are sure no flammable vapour has built up.
• Open the roller doors to ventilate before entering.
• Wear chemical-resistant gloves, boots, eye protection and masks suited to the substances.

Handle chemicals and waste

• Separate damaged oil drums, paint tins, thinner and batteries; never combine them.
• Send waste oil, spoiled paint and solvents, and batteries to licensed disposal contractors.
• Do not release oily water into public drains.
• Discard rags, masking paper, filters and anything that has absorbed chemicals.
• Photograph damage for insurance.

Wash and dry

• Remove mud; degrease floors per the product label; clean the interceptor and drains.
• Replace all booth filters and check extraction fans before use.
• Clean the lounge and discard soaked sofas or carpets.
• To disinfect washed surfaces such as counters, door handles and toilets, consider a medical-grade disinfectant like Chemgene HLD4H at the label dilution and contact time.
• Dry thoroughly; agencies such as the CDC advise cleaning and drying within 24 to 48 hours to limit mold.

Ozone and afterwards

• Confirm all flammable containers are sealed or removed from the treatment zone.
• Baseline TVOC, everyone out, doors closed, treat, rest, ventilate, follow-up TVOC.
• If repainting or laying new epoxy, plan a second treatment once it has cured.
• Store paint and chemicals above the previous flood line, in cabinets suitable for flammables.
• Painters still wear their normal protective equipment for every spray job.

FAQ: odours in garages after a flood

A paint shop always smells of thinner. Is ozone really needed?

Normal spraying odour should be handled by booth ventilation and painters' protective equipment. Post-flood odour is different: chemicals have spread through the whole building and soaked into floors, walls and the lounge. Ozone helps reduce that residue so the shop returns to its pre-flood condition.

Is it safe to use ozone in a garage that holds thinner and oil?

The team always surveys first. Open or leaking flammable containers must be removed and the rest sealed. Treatment does not go ahead where flammable liquid is still spilled or vapour is concentrated; it comes only after clearing and cleaning.

Can flooded car cabins be treated?

Yes, the service covers automotive work, but soaked carpet, insulation or seats must be removed, and the interior washed and dried first, with no people or animals in the car during treatment. The car's electrics and engine still need a mechanic's inspection and repair.

How long will we be closed?

It depends on size and number of zones. According to the service information, the space is ready about two hours after treatment. Many garages book evenings or holidays to avoid turning cars away.

Can ozone replace a painter's respirator?

No. Ozone deals with residual odour in the space, but during spraying painters still need respiratory protection and proper booth ventilation as usual.

Treat before or after new epoxy flooring?

Many garages do both: once after cleaning to remove flood odour, and again after the epoxy cures to reduce new-material odour. According to the service information, ozone handles epoxy odours.

A mechanic has fever and calf pain after shovelling mud. What should he do?

See a doctor quickly and mention wading through floodwater, as these can be signs of leptospirosis. Restoring the garage is not treatment for illness.

Garage still smelling of oil and thinner after the flood? Let WHD finish your recovery

Site survey, before-and-after TVOC, and zone-by-zone ozone for the workshop and vehicle cabins.

Ask about ozone for your garage

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

Related services

• Ozone chemical residue and odour removal
• Building ozone disinfection
• Chemgene HLD4H medical-grade disinfectant

References

• 2026 Bangkok floods (Wikipedia)
• Al Jazeera: Disaster zone declared across Bangkok
• CDC: Floods