Jira is the HR manager of a consulting firm, responsible for 68 employees on the twelfth floor of an office building in Sathorn. She compiles the monthly leave statistics, which made her the first person to notice something was wrong.

In the first quarter, average sick leave was 1.2 days per employee, entirely normal. In the second quarter it reached 2.8 days. In the third quarter it hit 3.4. What stood out was that the reported symptoms were not influenza but a strangely repetitive cluster.

• Nasal congestion and frequent sneezing, only while at the office
• Afternoon headaches and unusual fatigue
• Dry, stinging eyes and throat irritation
• A dry cough that disappeared over the weekend
• Itchy rashes on the forearms that rest on desks and chair arms

What convinced Jira this was not coincidence came during a two-week work-from-home period while the electrical system was upgraded. Sick leave dropped to almost zero, then climbed straight back the moment everyone returned to the office.

She took the data to the management meeting and was approved to investigate the building environment properly.

What Jira had found has a formal name: Sick Building Syndrome, a condition where occupants experience health symptoms associated with being in a specific building, which improve on leaving it.

The common causes in Thai offices are several, and almost all involve things nobody can see.

1. Wall-to-wall carpet that has never been deep cleaned. Office carpet is the single largest dust reservoir in a workplace, and many are more than five years old with nothing but surface vacuuming.
2. Task chair upholstery used eight hours a day. It accumulates perspiration, shed skin and moisture at levels most people never consider.
3. Fabric-covered walls and meeting room chairs. Large surface areas that are almost never in the routine cleaning schedule.
4. Central building air conditioning. It recirculates the same air and distributes particles across every zone.
5. Windows that cannot open. Modern office buildings are sealed, so natural ventilation simply does not exist.

In this environment, dust mites and allergens accumulate continuously, with no mechanism to reduce them other than deep cleaning.

Further reading on indoor air quality and occupational health is available from the World Health Organization and the Department of Disease Control.

Jira translated a health issue into the language executives act on: cost.

Cost of sick days. Sixty-eight employees taking an average of 2.2 additional sick days per quarter compared with Q1 equals nearly 150 lost working days in a single quarter.

Cost of reduced output. People who come in while symptomatic rarely perform at full capacity, a cost invisible in the accounts but very real in delivery.

Cost of delivery delays. A consultancy works in teams to fixed deadlines. When a team member disappears at short notice, the whole project slips.

Cost of attrition. Three employees resigned in six months, and one cited in the exit survey that the workplace environment was damaging their health.

Cost to employer brand. A company that says it cares about its people while its office makes them ill is a gap that younger employees notice very quickly.

Set against the price of one deep cleaning programme, the decision was made in the room.

Jira confirms the company employs two daily cleaners. So why was it insufficient?

1. Daily work targets what is visible. Bins, desks, walkways and washrooms, all necessary, none of it deep cleaning.

2. A standard office vacuum only reaches the surface. Dense commercial carpet needs far greater suction to lift contaminants from the base of the pile.

3. Bag vacuums exhaust fine dust back into the room. In a sealed office on central air conditioning, that dust spreads across the entire floor.

4. Chair upholstery is almost never scheduled. Despite being the surface in contact with employees for eight hours a day.

5. Meeting rooms are booked constantly. With no free window for deep cleaning, many companies keep postponing until it never happens at all.

The firm engaged the dust mite removal, carpet and upholstery cleaning service with full disinfection from World Health Disinfection, scheduled for a Saturday so operations were unaffected.

The team used the SIRENA System dust mite vacuum, combining water filtration with HEPA filtration down to 0.02 microns. The critical point for a sealed office is that all dust is captured in water rather than pushed back into the central air conditioning.

Scope covered the wall-to-wall carpet across the entire floor, 68 task chairs, chairs and fabric wall panels in three meeting rooms, the reception sofas, and every curtain, finishing with medical-grade disinfection throughout.

Jira says what silenced the management team was the photograph of the tank after the central office carpet was cleaned. The water had turned grey-black with thick sediment, from carpet that had been vacuumed daily for six years.

The team proposed a cycle matched to how an office is actually used.

1. Every six months: full carpet and all task chair upholstery.
2. Every three months: heavily used meeting rooms and client reception areas.
3. Every twelve months: curtains and fabric wall panels.
4. Immediately: after refurbishment, an office move, or a respiratory outbreak within the organisation.

A cycle like this makes budgeting predictable and lets management tie a clear indicator, sick leave rate, to the investment.

• Offices with wall-to-wall carpet more than three years old
• Sealed office buildings on central air conditioning
• Companies with abnormally high sick leave and no clear outbreak
• Clinics and hospitals with upholstered waiting areas
• Schools and tutoring centres with carpeted classrooms
• Banks, customer service centres and showrooms with reception sofas

Organisations wanting comprehensive coverage can combine this with the disinfection spraying service to address allergens and pathogens in a single programme.

Do we need to close the office?

How long will the carpet be out of use?

Is there a report for management?

Does this genuinely reduce sick leave?

How long does a large floor plate take?

Do you handle provincial sites or multiple branches?

For most HR and facilities teams the problem is not knowing what to do. It is showing leadership why the budget is justified. Jira set out the approach that worked in her meeting.

Step one: pull at least four quarters of sick leave data, then split it into leave with and without a medical certificate. A rise in the group without certificates usually reflects low-grade chronic symptoms linked to the environment.

Step two: find a natural comparison period, such as a work-from-home stretch, a long holiday, or a temporary relocation to another floor. If sick leave drops in those windows, you have a strong piece of evidence.

Step three: run a five-question survey. Ask only where symptoms occur, at what time, and when they improve. Short surveys get much higher response rates and produce sharper data.

Step four: convert it to money. Multiply lost working days by the average daily cost of an employee, then set that against the cost of one deep cleaning programme. That number usually argues the case for you.

Step five: propose it as a pilot. Ask for one floor or one zone first and measure against an untreated zone. This lowers the perceived risk and is approved far more readily than a whole-building request.

Step six: capture before and after photographs every time, especially the tank water after carpet cleaning, because it communicates instantly without any technical explanation.

When technicians survey an office building, the items found to be absent from any deep cleaning plan are almost always the same set.

• Under desks and along cable runs, where a standard vacuum cannot reach past desk legs and cable trays.
• Carpet at lift lobbies and entrances, which receives more shoe-borne soiling than anywhere else in the building.
• Chairs in rarely used meeting rooms. The less a room is used, the less anyone thinks about it, while dust settles just the same.
• Fabric wall panels and acoustic boards, large surfaces that trap dust extremely well and are almost never cleaned.
• Staff break-area sofas, heavily used at breaks and usually carrying food debris as well.
• Carpet under photocopiers and filing cabinets, which accumulates both paper dust and toner particles.
• Fabric blinds and light-control shades, usually classified as decor rather than cleaning.

Including these in the scope from the start is what makes the outcome measurably different from daily cleaning, and materially improves the chance of hitting the indicator HR has set.

In an office building on central air conditioning, particles exhausted by a vacuum in one zone can travel across the entire floor within a short time.

Is there equipment certification documentation?

Can we set up an annual contract?

Does a company representative need to be present throughout?

How are areas with IT equipment handled?