Factory Smell Only Appears in the Afternoon How to Find the Cause Malaysia

Factory Smell Only Appears in the Afternoon How to Find the Cause Malaysia The factory smells normal in the morning. Then sometime after lunch, workers begin saying: “The smell is back.” By 3 PM, the complaint becomes stronger. By evening, it may disappear again. This pattern is extremely useful. The question is no longer simply: “What gas detector should we buy?” The better question is: What changes before the smell appears? An afternoon-only odour problem may be connected to: Production Schedule → Chemical Use → Temperature → Ventilation → Outdoor Conditions → Wastewater Activity → Loading Operations → Process Accumulation The investigation should therefore follow: Time → Process → Location → Possible Source → Measurement → Trend → Corrective Action → Re-Test 1. The Time Pattern Is a Clue If the smell occurs at approximately the same time every day, something may also be changing at approximately the same time. Ask: What starts before the smell appears? Does production increase? Is a chemical process started? Does cleaning begin? Does wastewater treatment change? Do trucks arrive? Does the factory become hotter? Does ventilation change? Time can lead you toward the source. 2. Build a Simple Timeline Instead of writing: “Smell in afternoon.” record: 8:00 AM No complaint 10:00 AM No complaint 12:00 PM Mild 2:00 PM Noticeable 3:00 PM Strong 5:00 PM Reducing Then add: What was happening in the factory at each time? This turns a vague complaint into a troubleshooting timeline. 3. Don't Measure Only in the Morning This is one of the easiest ways to miss the problem. If the complaint occurs at: 3 PM but measurement is performed at: 9 AM a normal result does not prove that the afternoon problem does not exist. Measure during the actual complaint period. 4. Establish a Morning Reference Morning measurements can still be valuable. Use them as a baseline. Depending on the suspected problem, measure appropriate: VOC Relevant Gas PM Temperature Humidity CO Air Velocity Then compare again when the smell appears. 5. Compare Morning vs Afternoon Now the factory can ask: Which parameter changed? For example: Morning VOC → Lower Afternoon VOC → Higher or: Morning Air Velocity → Normal Afternoon Air Velocity → Lower or: Morning Temperature → Lower Afternoon Temperature → Higher The pattern creates direction. 6. Temperature Can Affect Odour Complaints As the factory becomes hotter during the afternoon, some processes or materials may behave differently. The objective is not to assume: “Heat causes every smell.” Instead, compare: Temperature trend with: Odour timing to see whether they move together. 7. Production Load May Increase After Lunch Some factories operate differently throughout the day. For example: Morning → Partial production Afternoon → Full production If the odour appears only at full load, investigate the process operating during that period. 8. Chemical Use May Follow a Schedule Perhaps: Painting begins at 1 PM. Cleaning occurs after lunch. Solvent mixing occurs at 2 PM. Chemical transfer happens once per shift. This can explain why workers only notice the smell during certain hours. Ask for the actual process schedule. 9. Identify the Chemical Before Selecting the Detector If the suspected source involves a chemical process, ask: What chemical is being used? Can the SDS be provided? Then determine whether appropriate investigation involves: VOC screening Specific gas measurement or another suitable method. Do not assume one gas detector identifies every chemical odour. 10. VOC Can Be Useful for Appropriate Screening If volatile organic compounds are relevant to the process, suitable VOC measurements may help compare: Morning versus: Afternoon or: Process OFF versus: Process ON The important value is the comparison under defined conditions. 11. But VOC Does Not Identify Every Chemical A general VOC instrument should not automatically be interpreted as: “This number tells us exactly which solvent is present.” The chemical process and instrument capability must be understood. 12. Afternoon Ventilation Performance May Change A factory may have good airflow in the morning. Then: More machines start More extraction systems operate Doors close Air-conditioning load increases Filters become loaded Building pressure changes The air movement pattern may therefore change. 13. Measure Air Velocity Where ventilation is part of the investigation, an anemometer can help compare appropriate: Morning Airflow versus: Afternoon Airflow at relevant: Supply Exhaust Hood Louvre Work Area This may reveal a ventilation-related pattern. 14. Outdoor Air Can Also Change During the Day The source may not be inside the factory. Possible external influences include: Traffic Nearby construction Neighbouring industrial activity Loading operations Outdoor dust Where useful, compare: Indoor affected area with: Outdoor reference during the complaint period. 15. Wastewater Processes Can Create Time-Based Complaints Suppose the smell appears near: ETP / wastewater treatment every afternoon. Ask: Does pumping occur at that time? Is wastewater transferred? Is sludge disturbed? Does treatment activity change? Where an atmospheric hazard such as HS is identified as relevant, appropriate gas measurement may be required. 16. Loading Bay Activity Can Create Another Pattern Suppose trucks arrive mainly between: 2 PM and 5 PM. Workers then complain about exhaust smell inside the warehouse. Possible pathway: Truck Schedule ↓ Relevant Gas / PM Measurement Where Appropriate ↓ Indoor vs Loading Bay Comparison ↓ Airflow Investigation ↓ Ventilation / Idling Controls ↓ Re-Test Again, time leads to the source. 17. Data Logging Becomes Very Valuable Here An afternoon-only problem is exactly where logging can outperform random spot checks. For supported parameters, a logger can record environmental changes throughout the day. Then compare the graph with: Production schedule Worker complaint time Chemical use Ventilation operation 18. Overlay Process Events With Measurement Data Imagine the record shows: 8 AM Production starts 12 PM Temperature rises 1 PM Coating starts 2 PM VOC begins increasing 3 PM Worker complaints peak This is much more informative than: “VOC = X at 3 PM.” The timeline provides context. 19. Example: Solvent Smell Appears at 2 PM Every Day Factory complaint: “Workers smell solvent every afternoon.” Possible pathway: Map Time Pattern ↓ Check Production / Chemical Schedule ↓ Identify Chemical & Review SDS ↓ Morning Baseline ↓ Afternoon VOC / Relevant Measurement ↓ Check Extraction Airflow ↓ Locate Source ↓ Corrective Action ↓ Repeat During Same Afternoon Period The verification should reproduce the original condition. 20. Example: Smell Appears When Factory Gets Hot Customer: “The smell becomes stronger when the factory gets hotter.” Possible pathway: Temperature / Humidity Trend ↓ Identify Materials / Process ↓ Relevant VOC / Gas Measurement ↓ Ventilation Airflow ↓ Compare Morning / Afternoon ↓ Corrective Action ↓ Re-Test Do not assume temperature is the cause until the relationship is investigated. 21. Example: Smell Appears Near ETP Every Afternoon Possible pathway: Record Wastewater Operation Schedule ↓ Identify Potential Atmospheric Hazard ↓ Appropriate Specific Gas Measurement ↓ Compare Time / Location ↓ Ventilation Investigation Where Relevant ↓ Operational / Engineering Control ↓ Continue Monitoring as Required Now Environmental Monitoring connects to Water & Wastewater. 22. Example: Warehouse Smells of Exhaust After 3 PM Possible pathway: Check Truck / Forklift Schedule ↓ Identify Fuel / Source ↓ Relevant CO / PM Measurement Where Appropriate ↓ Indoor / Outdoor Comparison ↓ Airflow Mapping ↓ Ventilation Investigation ↓ Corrective Action ↓ Repeat During Peak Logistics Period This connects Environmental + Safety + Warehouse Operations. 23. What If the Smell Is Strong but the Meter Shows Nothing? Do not immediately conclude: “There is no problem.” Ask: Are we measuring the correct parameter? A detector measuring: CO will not automatically detect: VOC and a VOC meter does not automatically identify: Every specific toxic gas. The measurement technology must match the suspected substance. 24. What If the Reading Changes Only Sometimes? Now logging or repeated time-based measurements may be more appropriate than one spot check. The objective is to capture: When Where and: Under what operating condition the change occurs. 25. Corrective Action Must Be Verified at the Same Time Suppose the factory repairs the exhaust. Testing only at: 9 AM does not prove that the: 3 PM complaint has been solved. Repeat measurements during the original problem period. This is true before / after verification. What Instruments Might Be Needed? Depending on the suspected source, a solution may include: VOC Meter For suitable VOC screening and trend comparison. Specific Gas Detector Where an identified gas requires measurement. Multi-Gas Detector Where its installed sensors match the identified hazards. PM2.5 / PM10 Meter For appropriate particulate screening. Temperature & Humidity Meter For environmental condition comparison. Environmental Data Logger For suitable time-based monitoring. CO Meter For appropriate occupied-space ventilation investigations. Anemometer For ventilation and extraction troubleshooting. The correct instrument follows: Time + Process + Source + Chemical + Location Don't Search Only for “Factory Smell Detector” There is no universal instrument for: “Something smells every afternoon.” The stronger questions are: What happens before the smell starts? Which process begins? Which chemical is used? Does temperature rise? Does airflow change? Do trucks arrive? Does wastewater activity change? The timing itself is part of the measurement solution. From Afternoon Complaint to Root Cause The better approach is: Complaint Appears at Certain Time ↓ Build Timeline ↓ Match Production / Chemical / Logistics Events ↓ Establish Earlier Baseline ↓ Measure During Complaint ↓ Compare ↓ Check Ventilation / Source ↓ Correct ↓ Re-Test at Same Time ↓ Keep Trend Data This is how an intermittent factory problem becomes measurable. One Afternoon Smell Can Connect Multiple MTM Solutions Environmental VOC → PM → Temperature → Humidity → CO Safety Specific Gas → Multi-Gas Facility Airflow → Ventilation → Extraction Monitoring Data Logging → Time Trend → Before / After Water & Wastewater ETP → HS / Relevant Gas Where Identified MTM is not simply supplying: “A smell detector.” The stronger positioning is: Tell us when the problem happens. We help determine what changes at that time. Factory Odour, Air Quality & Time-Based Environmental Monitoring Solutions Malaysia MTM Precision supports: Manufacturing plants Production departments EHS teams Safety officers Chemical processes Warehouses Wastewater facilities Facility managers Maintenance departments with measurement solutions covering: VOC Specific Gas PM2.5 / PM10 CO Temperature Humidity Airflow Ventilation Data Logging Environmental Trend Monitoring Smell Only Appears at Certain Times? Tell MTM: What time does it start? What production process begins before that? Which chemicals are used? Does the factory become hotter? Does ventilation change? Do trucks or forklifts become more active? Is wastewater activity involved? Does the smell disappear after production stops? MTM can help build the measurement pathway around the actual time pattern. MTM Precision Sdn Bhd Showroom & Service Centre No. 29-1 & 29-2, Jalan Bandar 18, Pusat Bandar Puchong, 47160 Puchong, Selangor, Malaysia WhatsApp: +6016-660 7346 Email: mtmpre@yahoo.com Website: www.mtmpre.com.my Don't just ask “What is the smell?” Ask “What changes before the smell appears?” Time → Process → Measurement → Source → Correction → Re-test.