How to Monitor PM2.5 in Factories and Warehouses During Haze Malaysia

How to Monitor PM2.5 in Factories and Warehouses During Haze Malaysia

During haze episodes in Malaysia, air pollution can affect not only residential homes and offices but also factories, warehouses, manufacturing facilities, logistics centres and industrial workplaces.

Industrial buildings often have different air quality challenges from ordinary offices.

Large roller shutter doors, loading bays, ventilation openings, vehicle movements and production activities may influence indoor particulate concentrations.

Outdoor haze particles may enter through open loading areas, while manufacturing processes may generate additional airborne dust or fine particles.

As a result, indoor PM2.5 in factories and warehouses can vary significantly between different locations and operating conditions.

Monitoring particulate trends can help facility managers investigate changes in air quality and identify areas requiring further assessment.

This guide explains how to monitor PM2.5 in Malaysian industrial facilities, select suitable monitoring locations, record measurements and understand the limitations of portable air quality instruments such as the Temtop S1 Up.

MTM Precision Sdn Bhd supplies portable air quality monitoring and industrial testing instruments for factories, warehouses, offices and commercial facilities throughout Malaysia.

1. Why Is PM2.5 Monitoring Important in Factories and Warehouses?

Factories and warehouses may be affected by both outdoor and indoor particulate pollution.

During haze, fine airborne particles can enter industrial buildings through:

Loading bay doors

Roller shutter entrances

Ventilation openings

Building leakage

Frequently opened access doors

Outdoor air intake systems

At the same time, industrial activities may contribute additional particles.

Examples include packaging operations, vehicle movements, material handling and certain manufacturing processes.

Monitoring can help facility managers understand how particulate concentrations change between areas and operating periods.

PM2.5 monitoring is useful for observing fine particle trends, but it does not identify every industrial airborne hazard.

2. What Is PM2.5?

PM2.5 refers to airborne particles with an aerodynamic diameter of 2.5 micrometres or smaller.

These particles may originate from combustion sources or form through atmospheric chemical reactions.

Common sources include:

Forest and peatland fires

Open burning

Vehicle exhaust

Industrial combustion

Diesel-powered equipment

Certain manufacturing activities

Welding and other thermal processes

Secondary atmospheric particle formation

PM2.5 concentration is commonly expressed in micrograms per cubic metre (µg/m³).

Exposure to elevated fine particulate concentrations is associated with respiratory and cardiovascular health effects.

However, a PM2.5 measurement does not reveal the chemical composition or toxicity of the particles.

A portable PM2.5 monitor measures or estimates a particle size fraction, not the identity of the airborne material.

3. Why Can Factories Be Affected by Outdoor Haze?

Many factories operate in buildings with frequent movement of workers, vehicles and materials.

Unlike sealed laboratory environments, industrial facilities may have large openings and substantial air exchange with the outdoors.

During haze, outdoor particles may enter through these pathways.

The degree of infiltration depends on:

Outdoor pollution concentration

Building construction

Door opening frequency

Ventilation arrangement

HVAC filtration

Wind conditions

Indoor airflow patterns

For example, a warehouse with frequently opened loading doors may experience different particulate conditions from an enclosed administrative office in the same building.

Industrial PM2.5 monitoring should consider building operations and outdoor pollution conditions together.

4. Outdoor Haze vs Industrial Dust - What Is the Difference?

Outdoor haze and industrial dust can both affect workplace air quality.

However, their sources and particle characteristics may differ.

ComparisonOutdoor haze particlesIndustrial process particlesTypical sourceFires, combustion and atmospheric processesManufacturing, handling and industrial operationsParticle sizeMay include substantial PM2.5May include fine and coarse particlesEntry pathwayOutdoor infiltration or ventilationGenerated inside the workplaceDistributionInfluenced by outdoor conditions and building airflowInfluenced by equipment and work activitiesMonitoringSuitable ambient particulate measurementsMay require process-specific and occupational measurementsMain control approachInfiltration management and filtrationSource control, engineering controls and appropriate ventilation

A high PM2.5 reading does not establish whether particles originated from outdoor haze or an industrial process.

Additional investigation may be required.

5. PM2.5 vs PM10 vs Total Dust in Industrial Environments

Industrial facilities may need to monitor several different particulate categories.

PM2.5

Fine particles with an aerodynamic diameter of 2.5 micrometres or smaller.

PM10

Particles with an aerodynamic diameter of 10 micrometres or smaller.

Inhalable Dust

An occupational sampling convention covering particles that may enter the nose and mouth during breathing.

Respirable Dust

An occupational sampling convention covering particles capable of penetrating into the gas-exchange region of the respiratory system.

Total Dust

A term used in certain sampling methods that should be interpreted according to the relevant method.

These categories are not interchangeable.

In particular, PM2.5 is not the same as occupational respirable dust.

An instrument displaying PM2.5 does not automatically provide measurements of inhalable dust, respirable crystalline silica or other workplace exposure parameters.

6. Can Temtop S1 Up Be Used in Factories?

The Temtop S1 Up Air Quality Monitor can be considered for general PM2.5 observations in suitable indoor environments, subject to its manufacturer's operating specifications.

Potential applications include:

Factory administrative offices

Enclosed meeting rooms

Staff rest areas

General warehouse air quality observations

Preliminary haze-related particulate monitoring

Comparison of indoor PM2.5 trends

However, the instrument should not automatically be considered suitable for:

Explosive atmospheres

Hazardous classified areas

Extreme dust concentrations

High-temperature industrial environments

Corrosive atmospheres

Formal occupational exposure compliance measurements

Certified personal dust exposure sampling

Always verify the instrument's measurement range, environmental operating limits and intended application before using it in an industrial facility.

7. Selecting Factory PM2.5 Monitoring Locations

A single measurement point may not represent an entire factory.

Industrial buildings may contain several areas with different particle sources and airflow conditions.

Useful monitoring locations may include:

Monitoring locationPurposeFactory officeObserve PM2.5 in an enclosed occupied areaProduction areaInvestigate general particulate trends where instrument use is suitableWarehouse storage areaObserve indoor particulate conditionsLoading bayInvestigate changes associated with outdoor air entryStaff rest areaObserve conditions in a regularly occupied spaceEntrance corridorObserve particulate changes near building access points

Monitoring points should be selected according to the investigation objective.

Avoid placing the monitor directly in an exhaust outlet, dust plume or other unsuitable location unless the instrument is specifically designed for that application.

Representative monitoring locations provide more useful information than measurements taken only where concentrations appear highest or lowest.

8. How to Monitor PM2.5 Near Loading Bays

Loading bays may experience frequent outdoor air exchange.

During haze, outdoor fine particles can enter when doors are opened.

Vehicle movements may also influence local particulate conditions.

A practical observation procedure includes:

Step 1 - Record the Initial PM2.5

Measure in a representative indoor area.

Step 2 - Record Door Conditions

Note whether loading bay doors are open or closed.

Step 3 - Record Vehicle Activity

Document nearby vehicle movements and relevant operating conditions.

Step 4 - Repeat Measurements

Use consistent monitoring intervals.

Step 5 - Compare Trends

Observe whether concentrations change during different loading activities.

Step 6 - Investigate Possible Sources

Consider outdoor haze infiltration and local industrial activities.

A PM2.5 monitor alone cannot conclusively distinguish diesel exhaust particles from outdoor haze particles.

9. How to Monitor PM2.5 in Warehouse Storage Areas

Warehouse storage areas may have different particulate conditions depending on the materials handled and the building layout.

Potential influences include:

Outdoor haze infiltration

Forklift activity

Packaging operations

Material movement

Dust resuspension

Ventilation

Cleaning activities

For general PM2.5 observations, choose a representative location away from direct mechanical damage and unsuitable environmental conditions.

Record the instrument location and operational conditions.

A warehouse PM2.5 reading should be interpreted together with the activities taking place at the time of measurement.

10. How to Monitor PM2.5 in Factory Offices

Factory offices may be affected by outdoor haze and nearby production activities.

For example, an office connected to a manufacturing area may experience particle movement through doors and ventilation pathways.

A general monitoring procedure includes:

Place the PM2.5 monitor in a representative occupied location.

Allow the instrument to stabilise.

Record the concentration in µg/m³.

Note air-conditioning and ventilation operation.

Record door and window conditions.

Repeat measurements at consistent intervals.

Review changes during different operating periods.

Avoid placing the monitor directly beside air-conditioning outlets or air purifier discharge points when the objective is to observe general room conditions.

Factory office PM2.5 monitoring can support particulate trend awareness but does not replace a complete indoor air quality assessment.

11. How to Monitor PM2.5 During Different Factory Shifts

Industrial operations may change between shifts.

For example:

Morning loading activity may increase vehicle movements.

Afternoon production may involve different equipment.

Night shifts may operate with different ventilation settings.

Cleaning activities may occur outside normal production hours.

Comparing measurements between shifts can help identify recurring particulate patterns.

However, measurements should be taken under reasonably comparable conditions.

Differences between shifts may reflect both operational activities and changing outdoor haze conditions.

12. Example Factory PM2.5 Monitoring Record

The following figures are hypothetical examples.

They are not actual Temtop S1 Up measurements or factory test results.

TimeMonitoring locationExample PM2.5Operating condition8:00 AMFactory office24 µg/m³Office occupied9:00 AMWarehouse35 µg/m³Normal storage activity10:00 AMLoading bay58 µg/m³Frequent door openings11:00 AMWarehouse41 µg/m³Material handling12:00 PMFactory office27 µg/m³Normal operation2:00 PMLoading bay62 µg/m³Loading activity

These examples illustrate how concentrations may vary across different areas.

However, the numbers do not identify the exact source or chemical composition of particles.

A monitoring record becomes more useful when PM2.5 readings are accompanied by location, time and operating conditions.

13. How to Compare Indoor and Outdoor PM2.5 at Industrial Sites

An industrial facility may wish to investigate whether indoor fine particles are influenced by outdoor haze.

A meaningful comparison requires PM2.5 concentration measurements expressed in compatible units.

For example:

Outdoor PM2.5: 50 µg/m³

Indoor warehouse PM2.5: 35 µg/m³

These are hypothetical values.

The indoor-to-outdoor ratio is:

I/O Ratio = Indoor PM2.5 / Outdoor PM2.5

35 / 50 = 0.70

This indicates that the measured indoor concentration is 70% of the measured outdoor concentration for the selected comparison.

However, the ratio alone does not establish the source of particles or the effectiveness of building filtration.

Instrument differences, measurement timing and local activities may influence the result.

Do not use Malaysia's API value as though it were an outdoor PM2.5 concentration in this calculation.

14. Malaysia API vs Factory PM2.5 Readings

Malaysia's Air Pollutant Index (API) is an official outdoor air quality indicator.

PM2.5 concentration is a separate measurement expressed in µg/m³.

For example:

Official outdoor API: 160

Factory indoor PM2.5: 40 µg/m³

These numbers cannot be compared directly.

The API is calculated using prescribed pollutant measurements and index methods.

The factory PM2.5 reading represents a fine particulate concentration at the instrument's location.

For official outdoor haze information, refer to Malaysia's Department of Environment.

Official APIMS website: https://apims.doe.gov.my/

Factory managers should use official API information for regional outdoor air quality awareness and suitable monitoring instruments for local particulate observations.

15. Can PM2.5 Monitoring Identify Industrial Dust Sources?

Not conclusively.

A PM2.5 monitor may indicate that fine particle concentrations have increased.

However, it cannot automatically determine whether the particles originate from:

Outdoor haze

Diesel exhaust

Welding fumes

Manufacturing processes

Packaging activities

Combustion equipment

Other sources

Source identification may require additional information or specialised measurements.

For example, welding fume assessment may require occupational hygiene sampling and evaluation of relevant metal constituents.

Similarly, crystalline silica exposure requires appropriate occupational sampling and analysis methods.

A PM2.5 reading should not be used as a substitute for substance-specific industrial hygiene assessment.

16. PM2.5 Monitoring vs Occupational Dust Exposure Assessment

This distinction is particularly important for Malaysian factories.

General PM2.5 Monitoring

Measures or estimates fine particulate concentration at a location.

It may help observe environmental trends.

Occupational Dust Exposure Assessment

Evaluates worker exposure using appropriate sampling methods, equipment and occupational hygiene procedures.

Depending on the hazard, assessment may involve:

Personal sampling

Inhalable dust sampling

Respirable dust sampling

Substance-specific laboratory analysis

Time-weighted exposure calculations

Relevant occupational exposure limits

In Malaysia, employers should consider applicable occupational safety and health requirements and obtain competent professional advice when required.

A consumer-grade PM2.5 monitor cannot establish compliance with occupational dust exposure limits.

17. Can Temtop S1 Up Replace Personal Dust Sampling?

No.

Personal dust sampling is designed to evaluate exposure in a worker's breathing zone using a defined occupational sampling method.

A portable general-purpose PM2.5 monitor typically measures particulate conditions at its location.

The two methods serve different purposes.

For example, a worker performing a dusty task may experience exposure that differs significantly from the PM2.5 concentration measured elsewhere in the factory.

Furthermore, occupational sampling may target particle fractions or substances that a PM2.5 monitor does not measure.

Use appropriate occupational hygiene equipment and methods when evaluating worker exposure or regulatory compliance.

18. How to Reduce Outdoor Haze Infiltration in Factories

Potential measures include:

Manage Unnecessary Door Openings

Reduce avoidable outdoor air entry where operationally practical.

Maintain Building Seals

Inspect obvious gaps around doors and windows.

Review HVAC Filtration

Verify the filtration capability of existing systems.

Maintain Filters

Follow manufacturer maintenance instructions.

Review Airflow

Consider how outdoor air enters and moves through the building.

Monitor PM2.5 Trends

Observe particulate changes after practical improvements.

However, industrial facilities may require substantial ventilation for worker safety, process control and equipment operation.

Never block required industrial ventilation or safety systems merely to reduce haze-related PM2.5 readings.

19. How to Manage Indoor Industrial Particle Sources

Outdoor haze is only one possible contributor to factory particulate pollution.

Indoor industrial sources may require dedicated engineering controls.

Examples include:

Local exhaust ventilation

Process enclosure

Dust collection systems

Appropriate housekeeping

Equipment maintenance

Material handling controls

Suitable filtration

The correct control depends on the process and airborne hazard.

For example, controlling welding fumes requires different considerations from managing general warehouse dust.

Source control and suitable engineering measures should take priority over relying only on general room air monitoring.

20. Can Air Purifiers Be Used in Warehouses?

Portable air purifiers may help reduce airborne particles in suitable enclosed areas.

However, large warehouses can have substantial air volumes.

A small domestic purifier may provide limited whole-building impact.

Important factors include:

Warehouse volume

Verified particle CADR

Existing ventilation

Door opening frequency

Airflow distribution

Industrial dust sources

Equipment suitability

Maintenance requirements

For large industrial spaces, a properly designed filtration or ventilation system may be more appropriate than several small domestic purifiers.

Industrial air-cleaning equipment should be selected according to building volume, pollution sources and applicable safety requirements.

21. Example of Air Purifier Sizing for a Warehouse Office

Consider a warehouse administrative office measuring:

Length: 6 metres

Width: 5 metres

Ceiling height: 3 metres

Room volume:

6 × 5 × 3 = 90 m³

At an illustrative target of five equivalent clean-air changes per hour:

Required Particle CADR = 90 × 5 = 450 m³/h

This is a preliminary mathematical estimate.

The appropriate target depends on existing filtration, ventilation and actual pollution conditions.

A recirculating air purifier does not automatically provide fresh outdoor air.

Air purifier CADR calculations should not be treated as a replacement for industrial ventilation design.

22. How to Use Temtop S1 Up for General Industrial PM2.5 Observation

A practical monitoring procedure includes:

Step 1 - Define the Objective

Decide whether the goal is to observe haze infiltration, compare rooms or investigate general particulate trends.

Step 2 - Check Instrument Suitability

Confirm that the location is within the instrument's operating limits and is not a hazardous classified area.

Step 3 - Select Representative Locations

Choose suitable monitoring points based on the investigation objective.

Step 4 - Record Initial PM2.5

Allow the instrument to stabilise according to the manufacturer's instructions.

Step 5 - Document Operating Conditions

Record:

Time

Location

Door position

Ventilation operation

Nearby activities

Outdoor haze conditions

Step 6 - Repeat Measurements

Use consistent intervals where practical.

Step 7 - Review Trends

Investigate recurring increases or differences between areas.

Step 8 - Escalate When Necessary

If the concern involves worker exposure to hazardous dust or fumes, arrange appropriate professional assessment.

Temtop S1 Up may support general particulate observations but should not be represented as certified occupational exposure monitoring equipment.

23. Common Mistakes in Factory PM2.5 Monitoring

Mistake 1 - Measuring Only One Location

A large factory may have different particulate conditions across multiple areas.

Correct approach: Select representative monitoring points.

Mistake 2 - Ignoring Outdoor Haze

Outdoor pollution may influence indoor readings.

Correct approach: Record relevant outdoor conditions.

Mistake 3 - Assuming All PM2.5 Comes From Production

Outdoor infiltration and other sources may contribute.

Correct approach: Investigate multiple possible sources.

Mistake 4 - Comparing API With PM2.5 Concentration

API is an index, not a direct concentration.

Correct approach: Use comparable PM2.5 measurements.

Mistake 5 - Using a Consumer Monitor for Occupational Compliance

General PM2.5 monitors do not replace occupational sampling methods.

Correct approach: Use appropriate industrial hygiene assessment.

Mistake 6 - Ignoring Instrument Operating Limits

Industrial environments may expose equipment to unsuitable conditions.

Correct approach: Verify specifications before use.

Mistake 7 - Blocking Industrial Ventilation During Haze

Ventilation may be essential for controlling hazardous process emissions.

Correct approach: Maintain required safety ventilation.

24. Frequently Asked Questions

Why should factories monitor PM2.5 during haze?

Monitoring can help facility managers observe fine particulate trends and investigate possible outdoor haze infiltration.

Can outdoor haze enter a warehouse?

Yes. Fine particles may enter through loading bays, doors, ventilation openings and building leakage.

Is PM2.5 the same as industrial dust?

Not necessarily. Industrial dust may include different particle size fractions and chemical substances.

Can Temtop S1 Up be used in a warehouse?

It may be used for general PM2.5 observations in suitable environments within its operating specifications.

Can Temtop S1 Up measure occupational respirable dust?

It should not be treated as an occupational respirable dust sampling instrument.

Can PM2.5 readings identify welding fumes?

No. PM2.5 measurements alone cannot identify specific metal fumes or their composition.

Is Malaysia API the same as factory PM2.5?

No. API is an official outdoor air quality index, while PM2.5 is a particulate concentration.

Can an air purifier reduce warehouse PM2.5?

Suitable filtration may help, but performance depends on building volume, airflow, pollution sources and equipment capacity.

Do factories need professional dust exposure assessment?

Where workplace hazards and applicable requirements warrant it, appropriate occupational hygiene assessment should be arranged.

Where can I buy a PM2.5 monitor in Malaysia?

Customers can contact MTM Precision Sdn Bhd in Puchong, Selangor, for Temtop S1 Up pricing and current stock availability.

25. Buy PM2.5 Air Quality Monitoring Instruments for Factories Malaysia

MTM Precision Sdn Bhd supplies portable air quality monitoring and industrial testing instruments for manufacturing, warehousing and commercial applications throughout Malaysia.

For suitable general indoor PM2.5 monitoring applications, the Temtop S1 Up Air Quality Monitor is one product option.

Potential applications include:

Factory office PM2.5 observation

Warehouse particulate monitoring

Indoor haze trend monitoring

Loading bay particulate comparisons

Staff rest area monitoring

General indoor air quality awareness

Air purifier performance observation

Preliminary investigation of particulate changes

Customers may contact MTM Precision for:

Temtop S1 Up pricing

Current stock availability

Product specifications

Portable PM2.5 monitor selection

General industrial air quality instrument enquiries

Warehouse and factory monitoring applications

Industrial testing instrument comparisons

For specialised occupational dust, gas or hazardous-area monitoring requirements, customers should identify the exact measurement parameters and applicable standards before selecting equipment.

MTM Precision serves customers throughout Selangor, Kuala Lumpur, Johor, Penang, Melaka, Negeri Sembilan, Perak, Pahang, Kelantan, Terengganu, Kedah, Perlis, Sabah and Sarawak.

Contact MTM Precision Sdn Bhd

Showroom & Service Centre

No. 29-1 & 2, Jalan Bandar 18,

Pusat Bandar Puchong,

47160 Puchong, Selangor, Malaysia.

Tel: 03-8080 7172

WhatsApp: +6016-660 7346

Email: mtmpre@yahoo.com

Website: www.mtmpre.com.my

Need a PM2.5 Monitor for Your Factory or Warehouse?

Contact MTM Precision for Temtop S1 Up pricing, current stock availability and assistance selecting a suitable portable monitoring instrument.

You may send us your factory application, monitoring location, required measurement parameters or existing instrument model through WhatsApp for an initial recommendation.

Conclusion

Monitoring PM2.5 in factories and warehouses during haze in Malaysia can help facility managers understand changes in fine particulate concentrations across different industrial areas.

Outdoor haze may enter through loading bays, ventilation systems and building openings, while indoor manufacturing and logistics activities may contribute additional particles.

A portable PM2.5 monitor such as the Temtop S1 Up can support general particulate observations in suitable environments.

However, PM2.5 monitoring does not identify every industrial dust hazard and cannot replace professional occupational exposure assessment.

An effective industrial air quality approach combines appropriate monitoring, source control, engineering measures, suitable ventilation and professional assessment where required.

For Factory PM2.5 Monitor Malaysia, Warehouse Air Quality Monitoring Malaysia and Temtop S1 Up Malaysia enquiries, contact MTM Precision Sdn Bhd in Puchong, Selangor.