Malaysia is once again facing an important reminder that clean air cannot be taken for granted.

In August 2026, haze affected multiple parts of the country. On 21 August, Serian, Sarawak recorded an Air Pollutant Index (API/IPU) of 227 — classified as very unhealthy. A day later, 11 locations were still recording unhealthy air quality, including Kuching, Samarahan, Sri Aman, Miri and Bukit Rambai in Melaka.

The Department of Environment (DOE/JAS) reported that deteriorating air quality in Sarawak was associated with haze moving from various directions. Regional hotspot activity has also been significant; on 20 August, 288 hotspots were detected in Kalimantan and 53 in Sumatra.

For Malaysian industries, however, the current situation raises a bigger question:

While we cannot control every source of ambient air pollution, how effectively are we controlling the emissions generated within our own facilities?

Understanding Air Pollution: Outdoor Air Is Only Part of the Story

Malaysia uses the Air Pollutant Index (API/IPU) to communicate ambient air quality and its potential effects on health. DOE categorises API readings as:

• 0–50: Good
• 51–100: Moderate
• 101–200: Unhealthy
• 201–300: Very Unhealthy
• Above 300: Hazardous

The API is an indicator of ambient outdoor air quality.

Inside an industrial facility, however, employees can face additional contaminant sources generated directly by production activities.

These can include:

Dust from grinding, sanding, crushing and material handling; fumes from welding and thermal processes; mists from machining and spraying; vapours and gases from chemicals and solvents; and particulate emissions from combustion and other manufacturing processes.

This is where proper industrial ventilation, Local Exhaust Ventilation (LEV) and Air Pollution Control Systems (APCS) become critical.

Haze Outside + Industrial Contaminants Inside = A Stronger Reason to Review Your Controls

The key lesson is simple:

Environmental air quality and occupational exposure control are related concerns, but they require different control strategies.

An API reading does not tell you whether your welding hood is capturing fumes effectively or whether your dust extraction system is maintaining its required airflow.

Those questions must be answered through proper industrial hygiene and engineering assessments.

Where Does Industrial Air Pollution Come From?

Different manufacturing processes generate different contaminants.

• A welding station may produce welding fumes.
• A woodworking facility may generate fine and coarse dust.
• A chemical mixing process may release vapours.
• A spray-painting operation can generate mist, overspray and volatile compounds.
• A grinding operation can mechanically propel particles away from the source.

Because the contaminants behave differently, there is no universal LEV design that works for every process.

Effective control starts by understanding:

Process → Contaminant → Source → Capture → Treatment → Discharge

Get the first part wrong and everything downstream can become less effective.

Your LEV System Is the First Line of Defence

Local Exhaust Ventilation is designed to capture contaminants as close as practicable to the point where they are generated, before they spread through the workplace.

A typical LEV system consists of:

Hood → Ducting → Air Cleaner → Fan → Stack

Each component has a specific function.

The hood captures the contaminant. The duct transports it. The air-cleaning device removes or treats contaminants where required. The fan creates the necessary airflow. The stack provides the final discharge path.

But there is an important catch:

A running LEV fan does not automatically mean an effective LEV system.

• Filters can become loaded.
• Ducts can leak or become obstructed.
• Fan performance can deteriorate.
• Processes can change.
• Hoods can be moved further from the source.
• Airflow can gradually decrease without operators noticing.

This is why inspection, performance verification and preventive maintenance matter.

Air Pollution Control Is Also a Compliance Issue

Industrial emissions in Malaysia are regulated under the Environmental Quality Act 1974 and its subsidiary regulations.

The Environmental Quality (Clean Air) Regulations 2014 establish requirements relating to industrial air emissions and air pollution control. DOE's Air Division is responsible for functions including the control of sources of air pollution and the administration of requirements under the Environmental Quality Act and related regulations.

For occupational exposure inside the workplace, engineering controls such as LEV also form an important part of controlling hazardous chemical exposure.

This means air pollution management should not be treated simply as:

“Something we deal with when DOE or DOSH comes for an inspection.”

It should be part of normal plant engineering and risk management.

Is Your Existing LEV or APCS Actually Performing?

This is one of the most important questions for plant managers, HSE teams and maintenance departments.

Consider these warning signs:

• Visible dust escaping from a hood may indicate inadequate capture.
• Fumes moving toward the operator can indicate poor hood positioning or insufficient airflow.
• Increasing differential pressure across filters may indicate loading or restriction.
• Frequent filter replacement can point to process or system problems that deserve investigation.
• Abnormal fan vibration, noise or current may indicate mechanical deterioration.
• Repeated worker complaints about dust, fumes or odour should never simply be normalised.

And perhaps the most dangerous situation is when:

Everything appears normal, but nobody has verified the actual airflow performance.

From Compliance to Prevention: What Industries Should Do

Current air pollution concerns provide a timely opportunity for factories to review their own emission and exposure-control systems.

A practical approach includes reviewing the contaminant-generating processes, assessing existing LEV and APCS condition, measuring airflow and pressure performance, checking hoods, ducts, filters and fans, reviewing maintenance history, and identifying whether the system still matches current production conditions.

For older systems, upgrading selected components may sometimes be more practical than immediately replacing the entire installation.

The objective should be:

Measure first. Understand the problem. Then engineer the appropriate solution.

How ZABSI Can Help Industries Manage Air Pollution at Source

ZABSI Industrial Ventilation provides engineering support across the lifecycle of industrial ventilation and air pollution control systems.

Our services include:

• LEV Consultation & Site Assessment
• LEV Design & Engineering
• LEV Installation / EPCC
• Testing & Commissioning
• LEV Inspection & Performance Verification
• Monthly, Quarterly & Annual Preventive Maintenance
• Dust Collector & APCS Maintenance
• Troubleshooting, Repair & System Upgrading
• Industrial Hygiene and Exposure-Control Support

Rather than looking at the fan, filter or duct individually, our approach considers the complete system and the process it is intended to control.

This allows industries to identify whether they need maintenance, optimisation, modification or a completely new system.

Don't Wait Until Pollution Becomes Visible

The current haze reminds us of something important:

We notice air pollution when we can see it.

But many industrial contaminants are not always visible.

A worker may stand beside an underperforming extraction system every day without realising that control performance has deteriorated.

A facility may continue operating because the fan is still running.

Then an assessment reveals that airflow is no longer sufficient.

That is why good air pollution management should begin before complaints, breakdowns or regulatory findings occur.

Protecting air quality starts with controlling what you can control — at the source.

Need to Review Your LEV or Air Pollution Control System?

If your facility generates dust, fumes, mist, vapours or other airborne contaminants, ZABSI can help assess your existing control system and recommend the appropriate next step.

Whether you require an LEV inspection, preventive maintenance, system upgrade or complete LEV design and installation, our team can support you from concept to compliance.

ZABSI Industrial Ventilation
📞 018-9530803
📧 sales@zabsi.com
🌐 www.zabsi.com

Engineering Workplace Compliance