The 2026 (B.E. 2569) Flood in Mueang Samut Prakan

According to a Thai Post report dated 25 September 2026 (B.E. 2569), Mueang Samut Prakan district had continuous rain from the morning, which grew heavier from the afternoon into the evening. Combined with a high tide, drainage was slow and water pooled deeply on several routes: Phraeksa Road, Srinakarin Road between the Si Thepha and Electricity Authority intersections, Theparak Road between the Si Thepha and Theparak intersections, and Sukhumvit Road in front of the Royal Thai Naval Academy. Authorities deployed water pumps at many points to drain the area.

These roads are the main arteries of retail in Samut Prakan. Both sides are lined with department stores, hypermarkets, supermarkets, convenience stores and community malls, most of which have wide car parks, ramps down to basement levels and loading docks at road level. When water from the street flows back in, what it leaves behind is not just wetness. It leaves mud, litter, sewage from storm drains and whatever the current carried along the way.

The national picture was serious as well. According to Department of Disaster Prevention and Mitigation (DDPM) data as of 06:00 on 7 October 2026 (B.E. 2569), published by the Government Public Relations Department, floods affected 27 provinces plus Bangkok, covering 123 districts and 984 sub-districts, with 1,154,875 households and more than 3.1 million people affected. The 2026 floods were not a local event, and retailers in low-lying or coastal areas should prepare a post-flood recovery plan in advance.

Example Case: The Night a Supermarket Had to Be Ready by Morning

Note: this is a typical scenario built from situations we see often. It does not refer to any real store or person.

Ton manages the building of a mid-sized community mall on a main road in Mueang Samut Prakan. On the evening of the heavy rain he watched the water slowly drain from the car park. It had flooded the front parking area, the ramp to the basement and the rear loading dock of the supermarket that anchors the mall. When the floor finally appeared, it was covered with a thin film of mud. A sour smell rose from the drains, plastic bags clung to the pillars and the water line on the walls sat almost at knee height.

His problem was simple to state. The supermarket had to open in the morning. Fresh produce trucks would back into the dock before dawn. Shoppers would walk through the entrance and push trolleys across the car park. Every area the water had touched needed to be cleaned and disinfected before anyone used it. His housekeeping team had buckets, mops and two hand-pumped sprayers. A quick calculation told him that spraying the entire car park with hand pumps would run well past opening time, and some places, such as the underside of the ramp beams or the gaps between pallet racks, were out of reach anyway.

That night Ton learned that reopening safely and quickly depends less on the number of people and more on the tools they use. Stories like this are why many retail organisations now look for an engine-powered backpack mistblower that their own team can use as soon as something happens.

Why Flooded Areas of a Mall Must Be Disinfected

Urban floodwater is not clean rainwater. It mixes with sewage from drains, manholes, rubbish and waste. When it recedes, several groups of microorganisms remain on floors, walls, table legs, trolley wheels and wooden pallets, which are surfaces customers and staff touch every day.

• Bacteria such as E. coli and Salmonella arrive with sewage and faecal matter and cause diarrhoea and food poisoning. Standing water also carries a risk of Leptospira, the cause of leptospirosis, which is common where rats are present, such as loading docks and bin rooms.
• Viruses such as norovirus and rotavirus cause diarrhoea and vomiting and spread easily through contaminated surfaces. Respiratory viruses such as influenza and RSV also spread well when people crowd indoors during the rainy season.
• Moulds grow quickly on damp walls, ceilings, entrance mats, cardboard boxes and wooden pallets, causing musty smells and black stains and triggering allergies in staff and shoppers.

For businesses selling fresh food, meat, vegetables and bakery items, leaving these microorganisms near cold rooms or product walkways is a risk that should not be allowed, both for consumer health and for the store's hygiene standards.

The Pain Points for Malls and Supermarkets After the Water Recedes

Many people assume that once the water is gone, washing the floor is enough. In reality, mall managers face pressure from several directions at the same time.

Huge areas. A single mall car park can cover thousands of square metres, before counting ramps, walkways around the building, event plazas and loading docks. Spraying all of that with small equipment takes an enormous amount of time.

Limited labour and time. Housekeeping and maintenance teams are small and must juggle many jobs at once: moving stock out of the water, checking electrical systems, removing mud and resetting the store. The time left for disinfection is usually just the night before opening.

Pressure to reopen. Every hour closed is lost sales, and tenants are waiting to reopen their shops. At the same time, nearby communities that have just been through a flood need to buy food, drinking water and essentials, so a mall plays an important part in the recovery of the area.

Health risk. Staff who wade through water and shovel mud are exposed to waterborne disease. Shoppers bringing young children or older relatives walk over areas that were flooded. If people fall ill after visiting, the impact comes straight back to the mall.

Brand reputation. Customers photograph and review everything on social media. One picture of a muddy car park or a complaint about a musty smell can do a lot of damage. A mall that can say "we have cleaned and disinfected every area" regains trust much faster.

Why Hand Pumps, Buckets and Small Sprayers Fall Short in a Mall

The equipment housekeeping teams already own is fine for daily work, but it was never designed for post-flood recovery over large areas.

• Hand-pumped backpack sprayers need constant pumping to keep pressure. The spray is uneven, the droplets are fairly large and the reach is short, so the operator must walk close to every surface. They tire quickly, and a car park takes a very long time.
• Buckets and mops are right for removing mud, which must be done first, but they cannot spread disinfectant evenly onto walls, pillars, beam undersides and corners.
• Small battery sprayers are convenient in small rooms, but across thousands of square metres the airflow and reach are often not enough, and the work stops while batteries recharge.

What a mall needs is a sprayer with strong airflow, long reach, a large enough tank and a design one person can carry anywhere. That is the gap an engine-powered backpack mistblower fills.

SOLO PORT 423: The Answer for Large-Area Disinfection in a Mall

The SOLO PORT 423 is an engine-powered backpack mistblower made by SOLO Kleinmotoren GmbH in Germany. An engine-driven fan produces a strong air stream, and liquid flowing from the tank is fed into that stream, where it breaks into fine droplets and is carried a long way and spread widely. This is different from sprayers that rely on liquid pressure alone.

Key specifications, according to manufacturer SOLO

• Single-cylinder 2-stroke engine, displacement 72.3 cm³
• Engine power 3.0 kW (4.1 HP)
• Spray liquid tank 12 litres
• Maximum airflow 1,400 m³/h
• Horizontal reach about 12 metres
• Dry weight 11.0 kg
• Sound pressure at the operator 97 dB(A)

In addition, according to WHD's product information, the unit can be set up for ULV-type output with droplets below 30 microns, which helps save chemical. The droplet size you actually get depends on the nozzle and settings used. WHD also lists other features: a Nikasil-coated cylinder, MAHLE and BING components, a rotatable spray tube, a long nozzle and a wide-angle diffuser, a UV-resistant translucent tank with a wide filler opening, a one-hand control lever for throttle, dosing and stop, a padded harness and four-point anti-vibration mounts. For other optional kits, ask the dealer.

How it works in a mall. Picture a basement car park after the mud has been washed out. One staff member carries the unit along the parking bays and points the spray tube at walls and pillars. The air stream carries disinfectant droplets onto surfaces along the whole row, including corners under beams, the edges of drains and walls that still show the water line, places a hand pump cannot reach. At the loading dock the operator can cover the apron, the edges of roller doors and the pallet area in a short time.

One point is essential: the sprayer only delivers the liquid. How well it disinfects depends on the chemical. Use a properly registered disinfectant according to its label, for example Chemgene HLD4H, which WHD sells, at the dilution and contact time the label specifies. Always remove mud and dirt first, because a disinfectant cannot work properly on a surface still covered in mud.

Get It Right: The SOLO PORT 423 Is Not a Thermal Fogger

Many people search for a "fogging machine for disinfection" when they need a sprayer for large areas. The SOLO PORT 423 is a mistblower, not a thermal fogger. A thermal fogger uses heat to turn the liquid into white smoke-like fog and is mostly used for mosquito and insect control. A mistblower uses air to break the liquid into droplets without heat, which makes it well suited to applying water-based disinfectants onto surfaces in buildings and car parks. In a mall full of finishes, signs and areas near merchandise, a mistblower with the right disinfectant is easier to control.

10 Reasons Malls and Supermarkets Should Keep a SOLO PORT 423 On Site

1. Covers big areas fast. A maximum airflow of 1,400 m³/h, according to SOLO, lets the team finish car parks and docks before opening.
2. About 12 metres of horizontal reach. It reaches walls, pillars and beam undersides without walking up to every point, and without stepping on areas already sprayed.
3. A 12-litre tank. Fewer refills and longer runs than small sprayers.
4. One operator is enough. No hoses or fixed pumps, so it moves to every floor and zone.
5. No mains power needed. It runs on an engine, so it works even while some circuits stay off for safety checks after the flood.
6. Saves chemical. According to WHD's product information, it can deliver ULV-type droplets below 30 microns, spreading disinfectant evenly with a sensible volume.
7. One-hand control. Throttle, dosing and stop sit on one lever, so the operator can stop instantly if someone walks by.
8. German engine durability. WHD lists a Nikasil cylinder and MAHLE and BING parts, suited to repeated use every rainy season.
9. Useful all year. Use it for routine disinfection of car parks, bin rooms, loading docks and common areas to maintain hygiene standards.
10. Your team controls the timing. No waiting in a contractor's queue when every business in the area needs help at once. Spray right after closing, and ask for a SOLO PORT 423 quote on the product page.

Before and After a SOLO PORT 423 Joins the Building Team

Step by Step: Disinfecting a Mall or Supermarket After a Flood With the SOLO PORT 423

These steps are general guidance for building teams. Always adapt them to your floor plan, the chemical label and the manufacturer's manual.

1. Check safety before entering

Have an electrician check any electrical system that was under water before switching it on. Look for structural damage and ventilate basements. Never run an engine in an enclosed space without ventilation.

2. Divide the site into zones and set priorities

Split the building into zones such as the loading dock, bin room, ramps, each car park level, the main entrance and the trolley bay. Start with areas linked to fresh food and the routes most shoppers use.

3. Remove rubbish and wash out all mud first

Clear litter, plastic bags and items ruined by water, such as cardboard and mats. Pressure-wash or scrub mud off floors, walls and drains. This is the most important step, because disinfectants work best on clean surfaces.

4. Protect goods and equipment

Move or cover merchandise, especially food, digital signs and electronics. Close cold room doors and food sales areas. Never spray toward goods on display.

5. Mix the disinfectant by the label

Choose a registered disinfectant such as Chemgene HLD4H and dilute it exactly as the label says. Fill the 12-litre tank through the strainer while the unit sits on level ground.

6. Spray with the wind, from the inside out

Put on full protective equipment and start the engine as the manual describes. Walk at an even pace, pointing the tube at walls, pillars, floors and corners. Start at the far end of each zone and back out, so you never walk through sprayed areas. Outdoors, avoid spraying into the wind.

7. Allow the contact time

Close the zone with cones and warning signs. Leave the disinfectant on surfaces for the contact time on the label, then ventilate well before letting anyone in.

8. Wipe high-touch points by hand

Trolley handles, baskets, handrails, lift buttons and counters should also be wiped with a suitable product, because hands touch them directly.

9. Record and communicate

Log the zone, time, chemical and operator. Use the record with tenants and customers, and to improve the next emergency plan.

10. Clean the machine after use

Dispose of leftover mix as the label directs, rinse the tank and lines with clean water, check the air filter and nozzle, and store the unit dry and ready for next time.

Safety When Using the SOLO PORT 423 in a Mall

• Hearing protection. Sound pressure at the operator is 97 dB(A), according to SOLO. The operator must wear ear muffs or plugs every time, and nearby staff should be warned in advance.
• Vibration and working time. Engines vibrate. Limit spraying time per session, rotate operators and take regular breaks.
• Chemical PPE. Wear chemical-resistant gloves, goggles or a face shield, a respirator suited to the chemical, long sleeves or coveralls and boots, following the chemical's label and safety data sheet (SDS).
• Refuelling. Switch off the engine and let it cool before refuelling, away from flames and sparks. Never refuel inside a closed building, and mix fuel as the manufacturer's manual specifies.
• Weight. The dry unit weighs 11.0 kg. With a full 12-litre tank and fuel it weighs about 23 kg or more. Adjust the harness snugly and lift it onto your back with correct posture.
• Keep people and animals out of the spray zone. Spray after closing, cordon off the zone, never spray toward people, and wait for the re-entry time on the label.
• Ventilation. In basement car parks, run the ventilation fans, because the engine produces exhaust.
• Training before real use. Operators should be trained in starting, dosing, emergency stop and maintenance, using the manual and the dealer's guidance.

If staff who waded through water develop a fever, muscle pain (especially in the calves), diarrhoea or infected wounds, they should see a doctor promptly and mention their flood exposure.

Buy Your Own Unit or Hire a Disinfection Service?

For a retailer with several branches, or a mall with large car parks that need disinfecting several times a year, keeping a SOLO PORT 423 on site lets the team respond immediately and plan its own schedule. If your mall needs only a one-off job, or does not yet have a trained team, the WHD disinfection spraying service is a separate option. Both paths share one goal: giving customers back a clean and safe space as quickly as possible.

For other angles on this machine, read the Thai articles on SOLO Port 423 against dengue for municipalities and spraying against emerging disease for provincial public health offices.

Frequently Asked Questions (FAQ)

Which disinfection sprayer is best for a shopping mall?

For car parks, loading docks and large common areas, an engine-powered backpack mistblower such as the SOLO PORT 423 is a better fit than a hand pump, with maximum airflow of 1,400 m³/h and about 12 metres of horizontal reach, according to SOLO.

What is the SOLO PORT 423 price?

The price depends on quantity and order terms. Please request a quote on the SOLO PORT 423 product page, call 065-556-6294 or add LINE @whd268.

After a car park floods, should I wash first or disinfect first?

Always remove mud and rubbish first, then apply disinfectant. Mud and dirt stop the chemical from reaching the surface and reduce its effect.

Is the SOLO PORT 423 a thermal fogger?

No. It is a mistblower that uses air to break the liquid into droplets. It does not use heat the way a thermal fogger does.

How soon can a mall reopen after disinfection?

It depends on the chemical. Follow the contact time and re-entry time on the label, and ventilate well before letting shoppers in.

Can the SOLO PORT 423 be used in a basement car park?

Yes, but run the ventilation system at full power because the engine produces exhaust. The operator must wear full PPE, and nobody else should be in the zone.

How heavy is it, and can any staff member use it?

The dry weight is 11.0 kg according to SOLO. With a full tank it is about 23 kg or more. Every operator should be trained, fit the harness properly and spray in short shifts.

What disinfectant should be used in a mistblower in a mall?

Use a registered disinfectant whose label covers surface use and spraying, such as Chemgene HLD4H, and use it only as the label directs.

Is there a mall disinfection service if we do not want to buy a machine?

Yes. You can book the WHD disinfection service by phone at 065-556-6294 or LINE @whd268. It is a separate option from buying a unit.

Want a SOLO PORT 423 for your organisation? Ask for a quote today

View SOLO PORT 423 and Request a Quote

For specifications, a demonstration or a quotation, call 065-556-6294 or add LINE @whd268. The World Health Disinfection team can also advise on choosing a registered disinfectant and on safe operation.

Related Reading and Sources

• SOLO Port 423 against dengue, for municipalities and SAOs (Thai)
• SOLO Port 423 for provincial public health and emerging disease (Thai)
• Chemgene HLD4H disinfectant
• WHD disinfection spraying service (an option if you prefer not to buy)
• Thai Post, 25 Sep 2026 (B.E. 2569): roads flooded in Mueang Samut Prakan (Thai)
• Government PR Department: flood summary, DDPM data as of 7 Oct 2026 (B.E. 2569)
• CDC: Floods and cleanup guidance
• Department of Disease Control, Thailand