PM2.5 Explained: What It Is, Where It Comes From and Why It Matters for Indoor Air Quality
PM2.5 Explained: What It Is, Where It Comes From and Why It Matters for Indoor Air QualityCategory: Indoor Air Quality Knowledge CentreReading Time: 810 MinutesPrimary KeywordPM2.5Secondary KeywordsWhat is PM2.5PM2.5 MalaysiaIndoor PM2.5PM2.5 MonitorPM2.5 Meter MalaysiaIndoor Air Quality MonitoringKey TakeawaysBefore exploring the details, here are the most important facts about PM2.5:PM2.5 refers to airborne particles measuring 2.5 micrometres (纰) or smaller.These particles are invisible to the naked eye and can remain suspended in the air for extended periods.PM2.5 may originate from both outdoor and indoor sources.Monitoring PM2.5 helps organisations understand indoor particulate conditions as part of a broader Indoor Air Quality (IAQ) programme.Professional IAQ assessments usually evaluate PM2.5 together with PM10, CO, TVOC, HCHO, temperature, and humidity.What Is PM2.5?PM2.5 is the abbreviation for Particulate Matter 2.5.The "2.5" refers to the particle's aerodynamic diameter, which is 2.5 micrometres or smaller.For comparison:Human hair 6080 纰PM10 10 纰PM2.5 2.5 纰Because PM2.5 particles are extremely small, they can remain airborne for long periods and move easily through indoor environments.PM2.5 is one of the most widely monitored parameters in professional indoor air quality assessments.Where Does PM2.5 Come From?PM2.5 originates from a wide variety of sources.Outdoor SourcesExamples include:Road trafficDiesel enginesIndustrial emissionsConstruction activitiesSeasonal hazeOpen burningWildfire smokeNatural dustOutdoor particles may enter buildings through:DoorsWindowsVentilation systemsFresh-air intakesIndoor SourcesIndoor PM2.5 may be generated by:CookingCleaningOffice printersBuilding maintenanceRenovation workDust from occupant movementMaterial handlingEvery building has different particulate profiles depending on its activities.Why Is PM2.5 Important?Routine PM2.5 monitoring provides valuable environmental information.It allows organisations to: Compare different indoor locations Observe environmental trends Evaluate building performance Support facility management Monitor haze impacts Assess renovation activities Establish environmental recordsRather than relying on visual observations, PM2.5 measurements provide objective environmental data.Which Industries Monitor PM2.5?PM2.5 monitoring is commonly performed in:Commercial OfficesMeeting roomsOpen officesReceptionConference roomsHealthcareHospitalsClinicsMedical laboratoriesHealthcare officesEducationSchoolsUniversitiesLibrariesTraining centresManufacturingFactoriesWarehousesQuality laboratoriesProduction officesCommercial BuildingsHotelsShopping mallsRetail outletsGovernment buildingsResidentialHomesCondominiumsApartmentsNewly renovated housesPM2.5 vs PM10FeaturePM2.5PM10Maximum Particle Size2.5 纰10 纰Typical SourcesCombustion, haze, trafficDust, construction, road particlesIndoor MonitoringYesYesUsed in IAQ AssessmentsYesYes Professional environmental assessments usually monitor both parameters together.How Is PM2.5 Measured?Modern IAQ instruments typically use laser particle sensor technology to estimate airborne particle concentrations.Measurements can be recorded:In real timeAcross multiple roomsDuring different operating periodsBefore and after renovationDuring haze eventsAs part of routine facility inspectionsLong-term trend analysis is generally more valuable than relying on a single measurement.Best PracticesFor reliable PM2.5 monitoring:Select representative indoor locations.Avoid placing monitors immediately beside doors or air-conditioning outlets unless evaluating those areas.Measure during normal building operation.Compare readings between rooms.Monitor regularly to identify trends.Review PM2.5 together with other IAQ parameters.Common MistakesMany organisations: Measure only once. Measure only one room. Monitor only PM2.5. Ignore ventilation. Do not compare historical data.A structured IAQ programme provides much more meaningful environmental information.Frequently Asked QuestionsIs PM2.5 the same as dust?No. PM2.5 refers specifically to fine airborne particles measuring 2.5 纰 or smaller. Dust may include particles of many different sizes.Can PM2.5 enter buildings?Yes. Outdoor particles can enter through ventilation systems, windows, doors, and fresh-air intakes.Should PM2.5 be monitored with PM10?Yes. Monitoring both provides a broader understanding of particulate conditions.Is PM2.5 monitoring suitable for offices?Yes. Offices, schools, hospitals, hotels, factories, and commercial buildings commonly include PM2.5 monitoring as part of their IAQ programmes.Why Choose MTM Precision?MTM Precision Sdn. Bhd. is a trusted supplier of professional Indoor Air Quality (IAQ) monitoring instruments and environmental monitoring solutions in Malaysia.We support organisations across commercial buildings, manufacturing, healthcare, education, laboratories, government agencies, and environmental consulting by providing reliable monitoring equipment, technical guidance, and application support.Our solutions include:Indoor Air Quality MonitoringPM2.5 & PM10 MonitoringCO MonitoringTVOC & HCHO MonitoringBuilding IAQ AssessmentsPost-Renovation Air Quality TestingESG & Green Building MonitoringContact MTM PrecisionMTM Precision Sdn. Bhd.Showroom & Service CentreNo. 29-1 & 29-2, Jalan Bandar 18Pusat Bandar Puchong47160 PuchongSelangor, Malaysia Website: www.mtmpre.com.my Email: mtmpre@yahoo.com WhatsApp: +6016-660 7346Recommended ProductsTemtop M2000 2nd Ideal for CO, PM2.5, PM10, HCHO, temperature, and humidity monitoring.Temtop LKC-1000S+ 2nd Ideal for PM2.5, PM10, TVOC, HCHO, AQI, temperature, and humidity monitoring.
09 Aug 2026
