Control and monitor air emissions

Which regulator controls your emissions

In England and Wales, industrial activities that produce emissions are classified into three categories under the Environmental Permitting (England and Wales) Regulations 2016. The category determines your regulator:

Part A(1) - Environment Agency regulated

The most potentially polluting activities, including large combustion plants, oil refineries, chemical manufacturing, waste incineration, and metals processing. The Environment Agency (or Natural Resources Wales) regulates emissions to air, water, and land through an integrated environmental permit.

Part A(2) - Local authority regulated (LA-IPPC)

Medium-scale industrial activities regulated by your local authority under Local Authority Integrated Pollution Prevention and Control. These permits control emissions to air, water, and land.

Part B - Local authority regulated (LAPPC)

Activities that primarily cause emissions to air only. Your local authority regulates these under Local Air Pollution Prevention and Control (LAPPC). Common Part B activities include:

• Vehicle respraying and paint application
• Timber and furniture manufacturing
• Petrol vapour recovery (fuel storage and unloading)
• Dry cleaning using solvents
• Cement batching
• Coating and printing processes
• Foundries and metalwork below Part A thresholds
• Crematoria

The full list of regulated activities is set out in Schedule 1 to the Environmental Permitting Regulations 2016.

Emission limits in your permit

Your permit sets specific emission limit values (ELVs) for the pollutants your activity releases. These are legally binding conditions. Common pollutants with limits include:

• Particulate matter (PM10, PM2.5) - dust, smoke, and fine particles
• Nitrogen oxides (NOx) - from combustion processes
• Sulphur dioxide (SO2) - from burning sulphur-containing fuels
• Volatile organic compounds (VOCs) - from solvents, paints, and coatings
• Carbon monoxide (CO) - from incomplete combustion
• Heavy metals - from metalworking and waste treatment

ELVs are expressed as concentrations (mg/m3) or mass emission rates (kg/hour or tonnes/year). Your permit specifies which format applies. Exceeding any limit is a permit breach and must be reported to your regulator immediately.

Best available techniques (BAT)

Permit conditions are based on best available techniques for your sector. BAT reference documents (BREFs) and process guidance notes describe the techniques and emission levels your regulator expects. You must demonstrate you are using BAT to control emissions.

Monitoring your emissions

Your permit specifies what monitoring you must carry out and how frequently. There are two main approaches:

Continuous emissions monitoring systems (CEMS)

Large Part A installations often require continuous monitoring of key pollutants using automated instruments fitted to the stack. CEMS must be:

• Certified under the MCERTS scheme (the Environment Agency's Monitoring Certification Scheme)
• Calibrated and quality-assured in accordance with EN 14181
• Subject to regular annual surveillance testing

Periodic stack testing (manual monitoring)

Most Part B activities and smaller Part A installations require periodic stack emission testing rather than continuous monitoring. Testing must be carried out by an MCERTS-accredited organisation to ensure results meet regulatory standards.

Typical testing frequencies are:

• Annual for most regulated pollutants
• More frequently if your regulator has concerns about compliance
• After significant changes to plant, fuel, or operating conditions

Stack tests measure pollutant concentrations and flow rates from the chimney or vent. Results are compared against your permit limits. You must keep test reports and make them available to your regulator on request.

MCERTS requirements

The Environment Agency's Monitoring Certification Scheme (MCERTS) sets quality standards for emissions monitoring. Under MCERTS:

• Monitoring equipment must be MCERTS-certified
• Laboratories analysing stack samples must be MCERTS-accredited
• Organisations carrying out manual stack testing must hold MCERTS accreditation
• Individual technicians need MCERTS competence certification

Using non-MCERTS methods without prior written agreement from your regulator may mean your monitoring results are not accepted for compliance assessment.

Abatement equipment

If your raw emissions exceed permit limits, you need abatement equipment to reduce pollutant concentrations before they leave the stack. Common types include:

• Bag filters and cyclones - for particulate removal
• Scrubbers (wet or dry) - for acid gases and SO2
• Activated carbon adsorption - for VOCs and organic compounds
• Selective catalytic reduction (SCR) - for NOx reduction
• Thermal and catalytic oxidisers - for destroying VOCs

Your permit may specify which abatement techniques to use. You must maintain abatement equipment in good working order at all times. Equipment failures must be reported to your regulator and may require you to reduce or stop operations until the equipment is repaired.

Reporting requirements

All permit holders must report to their regulator. Requirements vary by permit type:

Part B (LAPPC) reporting

• Submit monitoring results as specified in your permit (typically annually)
• Report any breaches of emission limits within 24 hours
• Notify your local authority of changes to plant, processes, or operating hours
• Keep records of operating hours, raw materials used, and abatement equipment maintenance

Part A reporting

• Submit annual monitoring reports to the Environment Agency or NRW
• Report breaches immediately and follow up in writing
• Some sites must report to the UK Pollutant Release and Transfer Register (PRTR)
• Large combustion plants have additional reporting under the Industrial Emissions Directive (retained in UK law)

Inspections and enforcement

Your regulator will inspect your premises, sometimes without prior notice. Inspectors can:

• Enter your premises at any reasonable time
• Take samples and measurements
• Inspect and copy records
• Require you to provide information
• Seize equipment or materials if there is a risk of serious pollution

Obstruction of an inspector is a criminal offence.

If enforcement action is taken, your regulator may issue:

• Compliance notice - requiring you to take specific steps by a deadline
• Enforcement notice - requiring corrective action for permit breaches
• Suspension notice - stopping operations until issues are resolved
• Revocation notice - withdrawing your permit entirely
• Prosecution - for serious or repeated breaches, carrying unlimited fines and potential imprisonment