A Story from the Field: A Smell the Librarian Had Never Known

Khun Arunee has worked as a librarian at a public library in Mueang Sing Buri for almost twenty years. She knows the smells of a library by heart: old paper, printing ink, the plastic jackets of new arrivals, the faint dust of the local history shelf. But on the morning the floodwater finally drained away and she opened the door to the stack room at the back of the building, the air that rolled out was something she had never smelled before. It was a heavy, damp mustiness mixed with river mud and the sour, fermented odor of paper that has sat in water.

The stack room is where the library keeps its reserve copies, donated books still waiting to be catalogued, back issues of magazines and the local publications that do not fit on the public shelves. During the 2026 floods, water entered the room to roughly the height of a hand span and stayed for several days. Books on the lowest shelves wicked the water upward until their pages swelled. Cardboard boxes of donations sitting on the floor collapsed into soggy heaps. Within a few days, greenish gray spots of mold started to bloom along the spines.

What worried her even more was that the musty smell began drifting into the reading room at the front. That is where older residents come every morning to read the newspaper and where schoolchildren come in the afternoon to do their homework. One regular reader told her he started sneezing after only a short while at his usual table. Parents kept phoning to ask when their children could come back. Khun Arunee needed answers on two fronts: how to keep library users safe, and how to save the books that could still be saved.

Why a Flooded Stack Room Is a Bigger Problem Than It Looks

Paper Is a Perfect Sponge

Paper, cardboard boxes and hardcovers made from pressed board absorb water and humidity extremely well. Even books on shelves above the waterline never touched the flood directly, yet several days of very high humidity in a closed room leave them damp too. Damp paper is exactly the kind of surface mold loves.

A Closed Room With No Air Movement

Stack rooms are usually designed to be closed, with few windows, to keep out dust and sunlight. In normal times that protects the collection. After a flood, the same design traps moisture for a very long time. Mold spores circulate in the still air and settle on book after book.

Smell and Spores Travel to the Reading Room

Every time the stack room door is opened to carry out boxes, humid air and spores flow into the reading room. Users with allergies or asthma may sneeze, feel congested, cough or experience chest tightness. Young children and older adults are especially sensitive.

Risks to Staff and Volunteers

The people who carry wet books, mop floors and open moldy boxes are exposed to mud, standing water and large amounts of mold spores. Without masks, gloves and boots they face respiratory irritation, skin problems and the risk of leptospirosis, which can enter the body through cuts.

Limited Time and Limited Budgets

Most public libraries have small teams and modest budgets for new acquisitions. Every book that can be saved matters. At the same time, the library needs to reopen quickly, because for many children and older residents it is one of the few free, quiet, safe places in town.

The Most Important First Step: Triage the Books Before Anything Else

Disinfection fogging and ozone treatment do a great deal for the air, the surfaces and the smell. What they cannot do is turn a swollen, water-logged book back into a healthy one. So before the team is called in, the books should be sorted into groups.

• Group 1, dry with no smell and no mold: move these to a dry, well-ventilated room and keep them separate from the other groups.
• Group 2, slightly damp or musty but not swollen: stand them upright and fanned open a little in a shaded, breezy place. Avoid harsh direct sun. Let them dry slowly, then check whether the smell remains.
• Group 3, soaked and swollen or heavily moldy: ordinary books that can be replaced are usually best withdrawn from the collection under the library's own disposal procedures. Keeping them only preserves a source of mold.
• Group 4, rare books, local documents and old photographs: seal them in bags or closed boxes and consult a document conservation specialist. Do not wipe, scrub or put them into an ozone-treated room yourself without expert guidance.

Donated books that were never catalogued usually sit in cardboard boxes on the floor. Open those boxes one at a time in an open area. If a box has collapsed and the books inside have fused into a wet block, do not try to peel the pages apart. That releases spores and tears the paper further. Bag them and set them aside with the books to be withdrawn. Back issues of magazines and newspapers that exist in digital form or can be replaced are not worth heavy rescue effort.

During triage, staff should wear masks, gloves and long sleeves, work in a ventilated area, and photograph and list everything. That record will be needed for official reporting and for any disposal paperwork later.

Understanding Mold on Paper: What You Are Actually Fighting

Mold is not a single organism but a large family of fungi whose spores are present almost everywhere, all the time, in small numbers. Under normal conditions they stay dormant. What wakes them up is moisture. Once relative humidity in a room stays high for a day or two, and especially once a material has actually been wet, spores begin to germinate and send out fine threads into whatever they are sitting on. Paper is made of plant fibers bound with starches and sizing agents, which makes it both absorbent and nutritious from a mold's point of view.

That is why a stack room after a flood can change so quickly. On day one the books simply look wet. By day three or four there may be fuzzy white or gray patches on the edges of the pages. By the end of the first week, colonies can be visible on spines, covers and even on the cardboard of shelving labels. Each colony releases fresh spores into the air, which then land on drier books and wait for their chance. The musty smell people notice is produced by the mold itself as it grows, which is why the smell is a useful warning sign even before spots become visible.

This also explains why drying and air quality matter as much as cleaning. If the humidity in the room stays high, any book left in it is at risk, even one that was never touched by water. The goal of professional treatment is therefore to bring down the spore load in the air, treat the surfaces of the room, and give the library a clean, dry starting point from which staff can bring the collection back.

Protecting Staff and Volunteers During the Cleanup

Library teams are often small, and when disaster strikes, friends of the library, students and neighbors volunteer to help. Their goodwill is precious, and their health deserves to be protected properly.

• Masks: a well-fitting mask rated for fine particles is far better than a cloth mask when handling moldy books and boxes.
• Gloves and long sleeves: they reduce skin contact with mold and with mud that may carry bacteria.
• Boots: floodwater and mud can carry the bacteria that cause leptospirosis. Cover any cuts completely, and anyone who develops fever and muscle pain in the weeks after cleanup should see a doctor and mention the flood exposure.
• Short shifts: rotate people so nobody spends hours inside the stack room. Take breaks outside in fresh air.
• Keep sensitive people out: volunteers with asthma, severe allergies or weakened immunity, and pregnant women, should take on tasks outside the moldy rooms, such as listing books or managing the drying area.
• Wash up: wash hands and change clothes before eating, drinking or going home.

Why the Usual Fixes Are Not Enough

• Fans blowing through the stack room: surfaces dry faster, but spores are blown onto the books that were still fine and out into the reading room.
• Bleach on the shelves: the fumes are harsh for staff, a drip on a book can damage or discolor the paper, and it does nothing about spores in the air.
• Air freshener sprays or bowls of charcoal: they may mask the smell briefly, but the moisture and mold that cause it remain.
• Putting damp books back on the shelves too soon: books that are still wet inside will grow new mold and pass it to their neighbors.
• Repainting walls immediately: concrete walls that sat in water keep releasing moisture for a long time. New paint blisters and the mold returns.

Each of these is understandable. People want to do something, quickly, with what they have. But a library is a room full of material that holds moisture, and it needs a plan that deals with the air, the structure and the collection separately.

The Solution: Chemgene HLD4H Disinfection and Controlled Ozone Treatment for Libraries

World Health Disinfection offers a professional disinfection fogging service using CHEMGENE HLD4H through ULV foggers, together with an ozone shock treatment service for enclosed rooms. In a library, the team adapts its methods to a space filled with paper.

• Disinfection of floors, walls, metal shelving and structure after books have been moved out. Disinfectant is not sprayed directly onto books.
• Ozone treatment of rooms that can be sealed to reduce airborne mold spores and break down the odor molecules embedded in the room.
• Controlled dose and duration matched to the room size. Ozone is a reactive gas, and prolonged high exposure can affect some materials.
• Rare books, photographs and important documents should always be removed before treatment.

Step-by-Step Process in a Library

1. Survey with the librarian: check how high the water reached, which rooms have mold, how air flows between the stack room and the reading room, and where computers are located.
2. Advice on triage and cleaning: help plan which groups of books move out first, which get bagged, and how to remove mud safely.
3. Remove or cover electronics: computers, printers, scanners and self-checkout units should be moved out or covered completely.
4. Disinfection fogging: the mist is applied to floors, walls, shelving, tables, chairs, restrooms and high-touch points.
5. Ozone treatment: the stack room and reading room are sealed and the ozone generator runs for the time the team specifies. No people, pets or plants may be in the room.
6. Ventilation: doors and windows are opened and the rooms aired thoroughly. The team confirms when it is safe to go back in.
7. Re-check and a plan for returning books: the team checks odor and mold spots and advises on returning the dry books to the shelves section by section.

10 Reasons Libraries Choose Professional Disinfection and Ozone Treatment

1. Fewer mold spores in the air: ozone treatment improves the air in both the stack room and the reading room.
2. Musty odor reduced at the source: not just covered with perfume.
3. Mist that reaches behind the shelves: ULV fogging gets into the gaps between shelving and walls and under cabinets.
4. A disinfectant used across many hygiene settings: CHEMGENE HLD4H is suitable for many surface types.
5. No spraying directly onto books: lower risk to paper and ink.
6. Ozone controlled for paper-heavy rooms: with clear advice to remove valuable items first.
7. Help planning the triage: staff do not have to guess which books to keep.
8. Faster reopening: children and older residents can return with confidence.
9. Aftercare guidance: including using the Chemgene 750 ml spray on reading tables and the circulation desk.
10. Dust mite care for carpets and cushions: children's reading corners with rugs or floor cushions can be supported by our dust mite removal service.

Before and After

A Voice from the Library

"What helped most was that the team did not just spray and leave. They helped us think through which groups of books had to come out first. Our old provincial publications were set aside so nothing touched them. After the ozone treatment and ventilation, the musty smell stopped drifting into the reading room, and the kids are back doing their homework."

— Khun Arunee, public librarian, Mueang Sing Buri (illustrative scenario)

A Step-by-Step Reopening Plan After the Service

• Day one after the service: keep the building ventilated all day and check the smell in the reading room and stack room.
• First week: reopen the front reading room first. Keep the stack room ventilated and keep an eye on the spots that had mold.
• Return books shelf by shelf: start with the fully dry group, keep books away from walls, and leave the bottom shelf empty until the walls are truly dry.
• Use moisture absorbers: and, if possible, place a hygrometer in the stack room so staff can read the humidity daily.
• Reopen the children's corner: once rugs and cushions have been washed or replaced.

Reopening in stages lets the library serve its community again quickly while still protecting the parts of the building that need more time to dry out completely.

Electronics, Equipment and Ozone: What to Move and What to Cover

A modern public library is not only books. There are public computers, a staff workstation, printers and photocopiers, a scanner for digitizing local documents, perhaps a projector in the activity room and a sound system for storytelling sessions. Ozone is a reactive gas, so the team always discusses equipment before treatment.

• Portable electronics such as laptops, tablets, cameras and external drives should be moved to a room that will not be treated.
• Large fixed equipment that cannot easily be moved is covered, and the ozone dose and run time are controlled to suit the room.
• Anything that was submerged must be checked by a qualified technician before it is powered on. Ozone treatment is not a substitute for an electrical safety check.
• Rubber items such as old mouse pads, rubber stamps and elastic bands on archive boxes can be affected by ozone over time and are best removed.

Communicating With the Community While the Library Is Closed

When a library closes after a flood, people worry. Parents wonder where their children will study. Older readers miss their daily newspaper routine. A short, honest update helps keep trust while the work is going on.

• Post a notice at the entrance and on the library's social media page explaining that the building is being cleaned, disinfected and treated for mold, and give an expected reopening window rather than a promise of an exact date.
• Explain that the reading room will open first and that some collections will return gradually.
• Ask borrowers who had books at home during the flood to check them, and to bring back any wet or moldy copies in a sealed plastic bag rather than putting them in the return box.
• Thank volunteers publicly. Recognition encourages people to help again with the next stage, such as relabeling and reshelving.

Libraries are trusted public spaces. Showing that the cleanup is being handled carefully, with attention to health as well as to the books, is part of rebuilding that trust after a hard season.

Frequently Asked Questions

Q: Will ozone treatment restore books that have grown mold?
A: Ozone reduces airborne spores and musty odor in the room, but it does not repair swollen or heavily stained books. Those should be withdrawn or sent to a specialist.

Q: Can valuable old books stay in the room during treatment?
A: This is not recommended. Always remove them first and consult a document conservation specialist about drying and mold management.

Q: Do the library computers need to be moved?
A: They should be moved out or completely covered. If they were touched by floodwater, have a technician check them before switching them on.

Q: How long will the library need to close?
A: Disinfection and ozone treatment can usually be completed in one day once triage and mud removal are done. Full reopening depends on how quickly the building dries.

Q: Can disinfectant be sprayed onto the books?
A: The team does not spray books directly, because adding moisture is bad for paper.

Q: Can staff remain in the building during ozone treatment?
A: They can work in parts of the building that are not being treated, but must not enter a treated room until the team has ventilated it and confirmed it is safe.

Q: Should we treat books that borrowers return damp?
A: Keep them sealed in a plastic bag away from the main collection, let staff assess them during triage, and withdraw any that are swollen or moldy rather than reshelving them.

Q: How do we know the stack room is dry enough to restock?
A: A simple hygrometer helps. Wait until humidity readings stay stable at normal indoor levels for several days, the walls feel dry, and there is no returning smell.

Q: Which areas do you serve?
A: Mueang Sing Buri, In Buri, Phrom Buri, Bang Rachan, Tha Chang, Khai Bang Rachan and nearby districts.

Let the Library Smell of Paper and Knowledge Again

Services for public libraries, school libraries and public agencies in Sing Buri Province

Book Ozone Treatment – Click Here

View Disinfection Service – Click Here

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

Related Articles and Links

• Ozone treatment for odors and chemical residue
• Dust mite removal service
• Master Ozone Generator
• All articles
• External sources: WHO: Floods and health and Thailand Department of Health

#LibraryOzoneTreatment #MoldyBooks #MoldRemoval #MustyOdorRemoval #PostFloodDisinfection #DisinfectionService #Chemgene #SingBuri

Keywords: library ozone treatment after flood, moldy books, library stack room, library disinfection, musty odor removal, Mueang Sing Buri, Sing Buri 2026