Air Quality Monitoring for Offices and Factories During Haze Malaysia
Meta Description: Learn how offices, factories and warehouses in Malaysia can monitor PM2.5 during haze, identify particle entry points and check ventilation and filtration performance.
Air Quality Monitoring for Offices and Factories During Haze Malaysia
Severe haze can affect more than outdoor visibility. Fine particles may enter offices, factories and warehouses through ventilation systems, loading bays, roller shutters, doors and gaps in the building.
Malaysia’s official Air Pollutant Index (API) provides essential information about outdoor air quality across a particular area. However, it does not show the exact conditions inside an individual office, production area, control room or warehouse.
A portable PM2.5 air quality monitor gives facility managers location-specific measurements that can help identify affected areas and evaluate existing filtration measures.
Why Workplaces Need Indoor Air Monitoring
Indoor pollution levels are not always the same throughout a building.
An enclosed management office may have relatively low PM2.5, while a nearby loading area may experience much higher concentrations. Conditions may also change when deliveries arrive, doors open or ventilation systems begin operating.
Workplace monitoring can help answer questions such as:
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Is outdoor haze entering the building?
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Which work areas have the highest PM2.5?
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Are office air purifiers reducing fine particles?
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Does the ventilation system introduce polluted outdoor air?
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Do loading activities cause particulate spikes?
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Are filter replacements producing an improvement?
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Is a control room better protected than the production floor?
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Does indoor air quality worsen during a particular shift?
Without local readings, facility teams may rely only on smell or visibility—neither of which can accurately determine PM2.5 concentration.
What Is PM2.5?
PM2.5 refers to airborne particles with a diameter of 2.5 micrometres or smaller.
During haze, these particles may originate from forest and peat fires, open burning, traffic or other combustion sources.
Industrial premises may also contain particulate matter produced by internal activities, including:
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Cutting and grinding
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Welding
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Material handling
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Packaging
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Diesel equipment
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Forklift movement
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Combustion processes
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Dusty raw materials
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Cleaning and sweeping
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Vehicle exhaust near loading areas
A general PM2.5 monitor can detect the presence and concentration of fine particles, but it may not identify their source or chemical composition.
Where occupational exposure to a specific substance is suspected, a more formal assessment and application-specific sampling method may be required.
API and Workplace PM2.5 Are Different Measurements
The official API represents regional outdoor air quality. A portable PM2.5 monitor measures particles at the instrument’s immediate location.
| Official API | Workplace PM2.5 Reading |
|---|---|
| Regional outdoor indication | Local measurement |
| Based on official stations | Taken inside or around the premises |
| Displayed as an index | Normally displayed in µg/m³ |
| Supports public advisories | Supports workplace investigation |
| Does not represent every room | Represents the selected measurement point |
Businesses should continue checking official API updates and follow directions from the relevant Malaysian authorities.
Portable monitoring provides additional information about the actual workplace.
Areas That Should Be Monitored
Offices
Recommended locations include:
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Reception
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Open-plan office
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Meeting rooms
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Management offices
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Server rooms
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Pantry areas
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Rooms close to external doors
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Spaces with air purifiers
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Areas with frequent complaints
Factories
Consider checking:
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Production areas
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Quality-control rooms
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Control rooms
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Maintenance workshops
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Worker rest areas
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Canteens
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Administration offices
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Areas near extraction systems
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Locations close to outdoor openings
Warehouses
Important points may include:
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Loading bays
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Roller-shutter entrances
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Packing areas
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Storage zones
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Dispatch areas
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Forklift routes
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Security posts
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Enclosed offices inside the warehouse
Testing multiple locations helps identify where particles are entering or accumulating.
Establish a Representative Baseline
Before making changes to the building, collect baseline readings.
Record PM2.5 under normal operating conditions, including:
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Number of occupants
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Doors and windows
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Ventilation status
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Air-conditioning operation
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Air purifier operation
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Production activities
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Loading activities
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Weather and outdoor haze conditions
The baseline can later be compared with readings taken after:
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Closing doors
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Adjusting ventilation
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Increasing purifier fan speed
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Replacing filters
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Relocating the purifier
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Sealing gaps
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Changing operating procedures
Without a baseline, it is difficult to demonstrate whether an improvement has actually occurred.
Correct PM2.5 Monitor Placement
Place the instrument in a representative occupied area at a suitable height.
Avoid positioning it:
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Directly in front of an air purifier
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Under an air-conditioning outlet
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Next to an open door
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Beside an operating machine
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Near vehicle exhaust
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Inside a cabinet
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Directly beside a local dust source
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Where it may be exposed to water, heat or physical damage
If the goal is to investigate a suspected pollution entry point, take one reading near that point and another in the main occupied area.
This comparison can reveal whether the local source affects the wider room.
Suggested Workplace Monitoring Procedure
Step 1: Review the Official API
Record the current API for the area, together with the date and time.
Step 2: Plan the Measurement Points
Select representative rooms, work areas and possible particle-entry points.
Step 3: Measure Under Normal Conditions
Allow the instrument to stabilise and record the PM2.5 reading without changing the workplace setup.
Step 4: Document Operating Conditions
Note the status of doors, ventilation, production equipment, air-conditioning and air purifiers.
Step 5: Introduce One Change
Close a door, start the purifier or adjust ventilation. Avoid changing several factors simultaneously if you want to identify which action caused the improvement.
Step 6: Repeat the Measurement
Measure again at the same location using the same instrument position and waiting period.
Step 7: Review the Trend
Compare the before-and-after results and repeat the test when outdoor haze conditions change.
Example Monitoring Record
| Time | Location | PM2.5 | Door Status | Filtration | Activity |
|---|---|---|---|---|---|
| 9:00 a.m. | Main office | 41 µg/m³ | Closed | Purifier on | Normal occupancy |
| 9:30 a.m. | Meeting room | 33 µg/m³ | Closed | Purifier on | Unoccupied |
| 10:00 a.m. | Warehouse centre | 72 µg/m³ | Open | None | Loading |
| 10:15 a.m. | Loading bay | 105 µg/m³ | Open | None | Truck unloading |
| 11:00 a.m. | Control room | 29 µg/m³ | Closed | Air-conditioned | Two workers |
These figures are examples only. Interpretation should consider the instrument, measurement method, local conditions and applicable guidance.
How to Check an Office Air Purifier
A PM2.5 monitor can help determine whether an air purifier is reducing particles in an office.
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Close external windows and doors where practical.
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Place the PM2.5 monitor in a representative area.
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Record the initial reading.
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Switch on the purifier.
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Maintain consistent room conditions.
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Record readings at regular intervals.
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Compare the results.
Keep the monitor away from the purifier’s clean-air outlet. Otherwise, it may display a low reading that does not represent the room as a whole.
If there is little improvement, check:
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Purifier capacity relative to room size
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Filter condition
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Fan-speed setting
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Purifier location
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Door-opening frequency
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Outdoor-air intake
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Building leakage
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Internal particle sources
Air-Conditioning Is Not the Same as Air Purification
A common misconception is that an air-conditioned office must have clean air.
Air-conditioning controls temperature, but its effect on PM2.5 depends on:
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System design
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Filtration efficiency
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Filter condition
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Outdoor-air intake
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Air leakage
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Maintenance
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Recirculation rate
Some systems may reduce particles, while others may introduce outdoor air or recirculate existing contaminants.
A direct PM2.5 measurement helps facility managers evaluate actual conditions instead of assuming that the system is providing sufficient filtration.
Does the Workplace Also Need CO₂ Monitoring?
Possibly—but CO₂ and PM2.5 measure different problems.
CO₂ monitoring can help assess ventilation and occupancy. A high CO₂ reading may suggest that an occupied space needs further ventilation review.
PM2.5 monitoring detects fine particles associated with haze, smoke and other particulate sources.
During severe haze, increasing outdoor ventilation may introduce more particles. Facility managers therefore need to balance indoor-air management requirements carefully and follow professional or official guidance where necessary.
A multi-parameter monitor may be helpful when both ventilation and particulate pollution must be investigated.
Spot Checks vs Continuous Data Logging
Spot Checks
Suitable for:
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Comparing rooms
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Finding particle entry points
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Testing an air purifier
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Checking conditions after complaints
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Conducting routine inspections
Continuous Data Logging
Suitable for:
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Monitoring an entire shift
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Identifying pollution spikes
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Comparing different working periods
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Documenting haze events
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Reviewing night and weekend conditions
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Evaluating filtration changes
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Maintaining facility records
For larger offices and industrial premises, data logging provides stronger evidence than occasional screen readings.
Common Monitoring Mistakes
Measuring Only in the Management Office
Conditions may be very different in production and warehouse areas.
Taking Measurements Directly Beside a Particle Source
This may be useful for identifying the source but may not represent worker exposure across the area.
Ignoring Changes in Work Activity
Loading, cleaning and production processes can affect readings.
Comparing Results Taken Under Different Conditions
The same location should be tested using consistent placement and procedures.
Assuming Haze Is the Only Source
Indoor industrial processes may also contribute to particle levels.
Using a General Monitor for Compliance Testing
A portable air quality monitor is useful for screening and investigation. It may not replace prescribed occupational hygiene sampling, regulatory methods or professional exposure assessments.
Selecting a Workplace Air Quality Monitor
Useful functions may include:
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PM2.5 measurement
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PM10 measurement
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Data logging
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Adjustable alarms
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Portable battery operation
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Temperature and humidity
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Computer or app connectivity
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Downloadable records
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Clear numerical display
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Protective carrying case
A portable instrument such as the Temtop LKC-1000S may be used for particulate spot checks in offices and general indoor locations.
For continuous workplace monitoring, select a model with suitable logging capacity and data-export functions.
Measure Before Making Assumptions
Air quality can differ significantly between two rooms in the same building.
During severe haze, workplace monitoring helps businesses:
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Identify affected areas
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Locate particle-entry points
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Evaluate air purifiers
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Review filtration performance
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Compare offices and production areas
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Document changes throughout a shift
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Support facility-maintenance decisions
A monitor does not remove pollutants and should not replace official instructions or a formal occupational exposure assessment. It provides practical, location-specific data that helps facility teams make better-informed decisions.
Contact MTM Precision
Contact MTM Precision for assistance selecting an air quality monitor for offices, factories and warehouses during haze in Malaysia.
MTM Precision Sdn. Bhd.
Showroom & Service Centre
No. 29-1 & 29-2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia
🌐 Website: www.mtmpre.com.my
📧 Email: mtmpre@yahoo.com
📱 WhatsApp: +6016-660 7346
01 Sep 2026
