A story from the field: the herbal scent that disappeared

Prasert chairs a community enterprise that processes herbs in Mueang Prachin Buri district. The group buys turmeric, Andrographis (fah talai jone), lemongrass and pandan leaves from local farmers. Members wash, slice, dry and grind the herbs, then pack them as herbal tea bags and powders for local shops and online stores. The plant is a single-storey building not far from the Prachin Buri River. It is divided into a washing and slicing room, a drying room with hot-air cabinet dryers, a grinding room, a packing room and a warehouse for dried raw materials.

During the 2026 floods, the Prachin Buri River burst its banks. Water flowed into the plant to a depth of about a foot and stayed for four days. Members managed to lift some sacks of raw material onto higher shelves, but sacks of dried turmeric sitting on low pallets and trays of herbs left in the bottom racks of the dryers were completely submerged.

When the water went down, the smell that came out of the building was not the familiar scent of lemongrass and turmeric. It was mud and damp. The walls of the drying room carried a clear water line. Sacks in the warehouse had started to show green and white mold spots, and herbal powder in containers that had not been sealed tightly had clumped together.

Prasert had orders waiting from several shops, and members urgently needed their income back. But he knew that products made in a building that still harbored mold should never reach consumers. His question was simple: what has to be done, and in what order? This article answers that question for herbal processors, community enterprises and small food and herb producers in the area. It explains what must be thrown away, who should check the machinery, where disinfection fogging and ozone treatment fit in, and how to keep the next batch of raw material safe and dry once production is running again.

Rule number one: flooded or moldy raw material is discarded, not dried again

This is the point many producers hope to find a way around, because raw materials are valuable. But it must be said clearly: herbal raw materials and products that have been in contact with floodwater, or that have grown mold, should not be used for production, even if they are dried again in the sun or in a dryer.

• Floodwater carries germs. Water that has flowed through a community may contain bacteria such as E. coli, which have no place in products that people will brew and drink.
• Some molds produce toxins. Some mold toxins are heat-stable, so drying moldy material again does not make it safe.
• Ozone treatment is not a way to rescue moldy material. Ozone helps treat the space and air inside the building. It does not make damaged raw materials usable again.
• Follow the regulator's requirements. Producers who hold licenses or registered products should follow the requirements of the Thai Food and Drug Administration (FDA) and the relevant good manufacturing practice standards. If unsure, consult the provincial public health office.

Keep a written list and photographs of discarded materials. They are useful for damage reports, applications for assistance and planning the next round of raw material purchases.

Risk points in a herbal processing plant after a flood

• Drying rooms. Walls and floors that sat in water stay very damp. When hot-air dryers are switched on again, the warm airflow can carry spores from walls and floors onto the next batch of herbs.
• Hot-air dryers and machinery. Dryers, slicers, grinders and sealing machines that were submerged must be checked by a technician or the equipment manufacturer before use, including electrical systems and motors.
• Drying trays and racks. Mesh trays and racks that were underwater have mud trapped in the mesh holes and corners.
• Raw material stores. Sacks and boxes on low pallets wick water upward, and mold spreads from wet sacks to neighboring ones.
• Packing rooms. This should be the cleanest area of all. Even a slight musty smell or a little mold here can affect packed products.
• Drains and gutters. Mud and herb residues trapped in drains are a source of odor and germs.

The cost of restarting too soon

Product quality. New raw materials brought into a building that still harbors mold may themselves go moldy within weeks, forcing another round of losses.

Consumers. Herbal products are bought by people who expect them to be clean and natural. If mold is found in a tea bag or a jar of herbal powder, trust in a community brand can be badly damaged.

Trade. Shops and online platforms may suspend sales after quality complaints, hitting the income of every member of the group.

Workers' health. Members working in damp rooms full of mold spores may suffer allergy symptoms such as coughing, sneezing and itchy eyes, and anyone who waded through floodwater with cuts or scratches is at risk of leptospirosis.

Why washing and running the dryers is not enough

• Running the dryers while the room is still damp. Besides the electrical risk if they have not been checked, hot air can spread spores and musty odors throughout the room.
• Washing floors with water only. This removes mud but does not kill germs carried in by the flood.
• Using strong bleach in production rooms. It can leave a chlorine smell that soaks into the next batch of herbs, which is the last thing you want for a product sold on its natural aroma.
• Repainting walls straight away. If walls are still damp, mold will bleed back through the new paint before long.

The members of a community enterprise usually work very hard after a flood. The goal is to make sure that effort goes into the steps that make a real difference, in the order that prevents having to do them twice.

The recommended recovery sequence

1. Sort and discard wet or moldy raw materials and products, recording them with photos and a list.
2. An electrician checks the building's electrical system, and a technician or the manufacturer checks dryers, grinders and other machinery that were submerged.
3. Remove mud and clean floors, walls, drying trays, racks and drains according to the plant's own production standards.
4. WHD disinfects surfaces throughout the building.
5. WHD ozone-treats the drying room, grinding room, packing room and warehouse while no raw materials or products are present.
6. Ventilate and let the building dry completely.
7. Clean product-contact surfaces again using the plant's standard procedure before production starts.
8. Bring in new raw materials and monitor warehouse humidity closely.

How WHD works in herbal processing plants

1. Site survey. The team walks through every room with the person responsible, checks how high the water rose and where mold and odors are worst, and confirms that raw materials and products have been removed from the space.
2. Preparation advice. We advise on removing mud, discarding damaged sacks and packaging, and covering or moving electronics such as digital scales and dryer control panels.
3. ULV disinfection fogging. Our disinfection service applies CHEMGENE HLD4H as a fine mist across floors, walls, racks, pallets and warehouse corners.
4. Ozone treatment. Rooms are closed and an ozone generator runs at a controlled dose matched to room size, reducing mold spores and breaking down musty odors in the drying room, packing room and warehouse. During treatment there must be no people, animals, plants, raw materials or products in the room.
5. Ventilation. Doors, windows and extraction fans are opened until the ozone has broken down and there is no sharp smell.
6. Re-check and advice. The team checks odor and condition and advises on raising sacks on pallets away from walls and controlling humidity in the warehouse.

Why fogging and ozone work as a pair

Fogging deals with surfaces. Floodwater leaves silt and bacteria on floors, lower walls, table legs, racks and pallets. A fine disinfectant mist reaches the gaps a scrubbing brush cannot.

Ozone deals with air and porous materials. Musty odors and mold spores lodge in plaster, ceilings and the hidden spaces of the building. Because ozone is a gas, it reaches those spaces, helping the drying room get ready for the next batch.

Neither replaces discarding and drying. Damaged items still have to go, and soaked walls need time to dry out. Our team will tell you honestly if any area is not ready yet.

Keeping the next batch of raw material free of mold

• Only accept raw materials that have been dried to the group's moisture standard.
• Place sacks on pallets raised off the floor and away from walls, and do not stack them so tightly that air cannot move.
• Use sealed containers for ground herbal powder.
• Install a humidity meter in the warehouse and record readings daily during the first month.
• Ventilate when the air is dry, and keep the store closed during rain or very humid periods.
• Check sacks by sight and smell every week, and separate any that show mold immediately.

Small habits like these cost very little compared with the value of a warehouse full of dried herbs, and they make it much easier to spot problems early.

Packaging, labels and the washing room

Packaging materials. Tea bag paper, foil sachets, jars, lids and printed labels are easy to forget, but they touch the product directly or carry the brand. Rolls of filter paper, cartons of empty sachets and stacks of labels that got wet or sat in a humid room should be checked carefully. Anything soaked, stained or musty should be discarded. It is far cheaper to reprint labels than to recall a product.

The washing and slicing room. This room uses a lot of water every day, so it is often assumed to be "already wet and fine". After a flood, however, sinks, washing tanks and floor drains may contain mud and sewage that backed up through the pipes. Tanks should be emptied, scrubbed and disinfected, drains flushed and cleared, and the water supply checked before fresh herbs are washed again. If the plant uses well water or a storage tank that was flooded, follow local health guidance on testing or treating the water before use.

Cutting boards and hand tools. Wooden boards and baskets that sat in floodwater are difficult to clean thoroughly and are often better replaced. Stainless steel knives and tools can usually be cleaned and disinfected.

A simple restart checklist for the production team

Before the first batch goes into the dryers, the person responsible for quality can walk through the plant with a short checklist. It takes less than an hour and gives everyone confidence that nothing has been missed.

• All flood-affected raw materials, products and packaging have been discarded and recorded.
• The electrician has signed off the building's wiring, and the technician has checked every dryer, grinder and sealer.
• Floors, walls, drains, trays and racks have been cleaned, and the building has been disinfected and ozone-treated.
• Rooms have been ventilated, there is no musty smell, and walls show no new mold along the old water line.
• Product-contact surfaces have been cleaned again using the plant's standard procedure.
• The warehouse humidity meter is installed and the first readings are recorded.
• Members have been briefed on hygiene, protective equipment and what to report if they notice mold or odor.

Keeping this signed checklist with the first batch records shows buyers and inspectors that the restart was handled carefully and systematically.

Buying raw materials from farmers after the flood

Farmers who supply the group may also have been flooded, and their own drying areas and storage may be affected. When restarting purchases, it helps to agree on simple checks: herbs should be harvested from plots where floodwater has receded and the plants are healthy, dried on clean surfaces off the ground, and delivered in clean, dry sacks. Rejecting a batch that smells musty is hard when everyone is struggling, but it protects the whole group. Explaining the reason kindly, and helping farmers improve drying where possible, keeps relationships strong.

Protecting members during the clean-up

In a community enterprise, the people cleaning up are often the same members who will return to production. Keeping them healthy is part of recovery.

• Wear boots and sturdy gloves when handling mud, wet sacks and moldy material.
• Cover cuts and scratches with waterproof dressings, since leptospirosis bacteria can enter through broken skin.
• Wear a mask when removing moldy sacks and sweeping dried mud, which can release dust and spores.
• Wash hands thoroughly before eating and at the end of each work session.
• Keep everyone out of treated rooms during ozone treatment and until ventilation is complete.
• Anyone who develops fever, muscle pain or other symptoms after flood clean-up should see a doctor and mention the flood exposure.

Talking to customers and shops about the recovery

Shops that stock community herbal products, and customers who buy online, often hear about floods in the news and may wonder whether products are affected. A short, honest update can protect your brand. Explain that stock affected by the flood was discarded, that the building was cleaned, disinfected and ozone-treated, that machinery was checked by technicians, and that production restarted only after these steps were complete. Sharing a few photos of the cleaned drying room and organized warehouse helps customers see the care that went into the recovery.

It is also wise to keep batch records showing which products were made after the restart. If a customer has a question later, you can show clearly that their product came from a clean, recovered plant.

Preparing for the next flood season

Prachin Buri sits along a river that can rise quickly in heavy rain. Planning ahead reduces losses next time.

• Keep the most valuable raw materials and finished goods on upper racks or in a higher part of the building.
• Agree on a trigger, such as an official flood warning, for moving stock and switching off machinery.
• Keep a list of machinery with model and serial numbers, and the contacts of technicians who can check them quickly.
• Store sealed plastic containers and spare pallets ready for emergency use.
• Plan with WHD in advance so disinfection and ozone treatment can be scheduled quickly once water recedes.

10 reasons Prachin Buri herbal producers choose WHD

1. We say plainly that moldy raw materials must be discarded. We do not sell services to rescue things that should not be used.
2. ULV disinfection fogging reaches pallet gaps, the space under racks and drying room corners.
3. Ozone treatment breaks down musty odors in drying rooms and warehouses, so the scent of herbs becomes the plant's main smell again.
4. We use CHEMGENE HLD4H for surface disinfection.
5. Ozone is only used in rooms without raw materials or products, for safety.
6. A clear division of work: dryers and machinery are checked by technicians or manufacturers, and WHD handles the space.
7. Controlled ozone doses, with advice on covering control panels and electronics.
8. Scheduling that fits the group's timetable for receiving new raw materials.
9. An optional mosquito spraying service around the building while water is still standing.
10. Easy to reach by phone and LINE, covering Mueang Prachin Buri and nearby districts.

Before and after recovery

Customer voice (example scenario)

"At first I could not bear to throw the raw material away and wanted to dry it again. The team explained that moldy material should not be used, so we discarded it and kept a record. After the technician checked the dryers, the team disinfected and ozone-treated the whole plant while the rooms were empty. Now the smell of lemongrass and turmeric is back, and our members feel confident starting work again."

— Prasert, chair of a herbal processing community enterprise, Mueang Prachin Buri (example scenario)

Frequently asked questions

Q: Can moldy raw material be ozone-treated and used again?
A: We do not recommend it. Raw material that touched floodwater or grew mold should be discarded. Ozone is for treating the space and air in the building, not for rescuing damaged material.

Q: Can raw material in sealed containers that stayed dry still be used?
A: It should be checked against the plant's standards and the regulator's requirements. If the container did not touch water and shows no sign of moisture or mold, the person responsible for quality makes the decision.

Q: Does WHD inspect or repair hot-air dryers?
A: No. Electrical and machinery checks are for a technician or the equipment manufacturer. WHD handles disinfection fogging and ozone treatment of the space.

Q: How long after ozone treatment can production restart?
A: The space must be ventilated until the ozone has broken down and there is no sharp smell, and product-contact surfaces must be cleaned again using the plant's procedure. The team will advise on timing after the survey.

Q: Do we need permission from any agency before restarting?
A: It depends on each producer's license type. Please ask the provincial public health office or your regulator directly.

Q: Do you serve plants in other districts of Prachin Buri?
A: Yes. Contact us on LINE @whd268 to arrange a survey.

Bring the scent of herbs back to your plant

Book a survey of your processing plant, drying room and raw material store in Mueang Prachin Buri and nearby areas.

Book Ozone Treatment - Click Here

See Disinfection Service - Click Here

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

Related links

• Ozone odor and chemical residue removal
• Master Ozone Generator
• CHEMGENE HLD4H spray, 750 ml
• All articles

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