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Global regulation

The global regulatory framework for air pollution cascades down from World Health Organisation (WHO) Air Quality Guidelines, which offer global guidance on thresholds and limits for key air pollutants that pose health risks.

WHO Guidelines

Regional legislation

Regional legislations set legally binding limits for concentrations of major air pollutants that impact public health. 


Regional and national authorities also set technology based standards for specific sectors. Such limits and standards are transposed into national law. It is the responsibility of national and local authorities to enforce the standards and to manage the performance of point sources.

There is significant disparity in regulation of air pollution from stationary sources from region to region and from application to application. This is illustrated in this overview of the regulatory process and standards within the European Union, United States, China, India and Latin America.

European Union

European Union

The The United Nations Economic Commission for Europe (UNECE) Convention on Long Range Transboundary Air Pollution (CLRTAP) has agreed a number of protocols.

The Gothenburg Protocol sets national emission reduction targets, including for fine particulate matter, to be achieved by 2020.

The Convention has been extended to eight protocols that identify specific measures to be taken by Parties to cut their emissions of air pollutants.

UNECE Convention

The Convention has 51 Parties and has eight protocols: 

1. The 1999 Protocol to Abate Acidification, Eutrophication and Ground-level Ozone (Gothenburg Protocol) and its 2012 amended version 

2. The 1998 Protocol on Persistent Organic Pollutants (POPs) and its 2009 amended version 

3. The 1998 Protocol on Heavy Metals and its 2012 amended version 

4. The 1994 Protocol on Further Reduction of Sulphur Emissions 

5. The 1991 Protocol concerning the Control of Emissions of Volatile Organic Compounds or their Transboundary Fluxes 

6. The 1988 Protocol concerning the Control of Nitrogen Oxides or their Transboundary Fluxes 

7. The 1985 Protocol on the Reduction of Sulphur Emissions or their Transboundary Fluxes by at least 30 per cent 

8. The 1984 Protocol on Long-term Financing of the Cooperative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe (EMEP)



Gothenburg Protocol

Under the Gothenburg Protocol, between 2005 and 2020 the EU member states must jointly cut their emissions of :

- sulphur dioxide by 59%

- nitrogen oxides by 42%

- ammonia by 6%

- volatile organic compounds by 28%

- particles by 22%


Gothenburg Protocol

National Emission Ceilings Directive

The 2001 National Emission Ceilings Directive (NECD) sets national emission ceilings for all Member States. In December 2013 the Commission published the European Clean Air Package including a revision of the NECD. The proposed revised NECD adopts the targets set out in the newly ratified Gothenburg Protocol for 2020 and contains new proposed emission ceilings for 2030, including new controls on methane and the primary emissions of particulate matter (PM 2.5). The proposals will be subject to discussion before any agreement or sign off by Member States.

In terms of industrial air pollution, according to the European Environment Agency, half of the air pollution cost burden was caused by just 1% of installations, mostly in Germany and Eastern Europe. Of the 30 biggest facilities it identified as causing the most damage, 26 were power plants, mainly fuelled by coal in Germany and Eastern Europe.



4th Quality Daughter Directive

The 4th Air Quality Daughter Directive (2004/107/EC) sets targets for levels in outdoor air of certain toxic heavy metals and polycyclic aromatic hydrocarbons. The Ambient Air Quality Directive sets local air quality limits for major air pollutants which may not be exceeded anywhere in the EU. Both are required to be transposed into national law.

Source-specific legislation is designed to limit emissions from specific economic sectors. Two Directives which impact most significantly on stationary installations are the Industrial Emissions Directive (IED) and the Medium Sized Combustion Plants Directive (MSCPD). Smaller combustion plants are regulated under the Ecodesign Directive (2009/125/EC).



Industrial Emissions Directive

- There are around 52,000 large industrial installations in Europe which fall under the IED (2010). 

- The IED applies to combustion plants designed for production of energy with a rated thermal input which is equal to or greater than 50 MW.

- “Best Available Techniques” are defined per sector in reference documents, or “BREFs”, that serve as benchmarks for environmental performance. 

- Under the BREFs, the competent authority needs to take BAT conclusions into account in permitting. According to Art. 15.3, the competent authority needs to set Emission Limit Values (ELVs), ensuring that, under normal operating conditions, emissions do not exceed the emission levels associated with the best available techniques (BATAEL), as laid down in the BAT conclusions.



Medium Combustion Plant Directive

- The Commission has proposed that EU air pollution limits should be extended to around 143,000 smaller energy plants and industry installations from 2025.

- The draft directive on medium-sized combustion plants (MCPs) aims to cut SO2, NOx and particulate emissions from installations with rated thermal inputs of between 1 and 50 megawatts.

- An MCP Directive Impact Assessment provides the following breakdown of the total number number of installations covered: 100,000 combustion plants between 1 and 5 MW; 23,000 plants between 5 and 20 MW 5,000 plants between 20 and 50 MW.

- The NOx pollution limits have been set at a level that requires only combustion-related modifications, not end-of-pipe abatement. 

- There are full exemptions from the SO2 and NOx limits for plants that run for less than 500 hours a year.

- It is estimated that 5% of plants in the 1-5 MW class, 10% of plants in the 5-20 MW class and 40% of plants in the 20-50 MW class are part of IED installations and, therefore, subject to the obligation to be covered by a BAT-based permit.



Non-road Mobile Machinery

Despite the very broad range of engines used by non-road machinery, only a very small proportion of the engines have a power greater than 560 kW. Taking all of the non-road engines used in construction, mining, agriculture and general industry together, it is estimated that greater than 99.9% of these non-road engines are less than 560 kW. The remaining 0.1% is used predominantly at remote sites in quarry and mining equipment.

European Directive 97/68/EC covers diesel fuelled engines for common NRMM. It became effective from 1 January 1999 for certain types of engines. Stage I (1 January 1999) and stage II (1 January 2001), covers diesel fuelled engines between 37 and 560 kW. The second directive, 2002/88/EC, extends the scope of 97/68/EC to cover spark ignited engines (petrol engines) up to 18 kW and held and non-handheld equipment. Stage I (and stage II) became effective in August 2004 with some exemptions for certain applications. A third directive, 2004/26/EC, extends the scope of 97/68/EC to cover diesel fuelled engines from 19 kW to 560kW for common NRMM.



Non-road Mobile Machinery

The different stages in the 2004/26/EC directive are as follows: 

- Stage III A covers engines from 19 to 560 kW including constant speed engines, railcars, locomotives and inland waterway vessels.

- Stage III B covers engines from 37 to 560 kW including, railcars and locomotives. 

- Stage IV covers engines between 56 and 560 kW. 

- Stage IV was effective from 1 January 2014. 

Stage III/IV requirements are harmonized to a large degree with the US Tier 3/4 standards. 



Each EU country nominates a ‘Competent Authority’ to operate a system of registration and permitting under the various Directives listed above. Using the example of the IED, the general principles governing the basic obligations of the operator, include:

- All the appropriate preventive measures are taken against pollution

- BATs are applied 

- No significant pollution is caused

United States

United States

The Clean Air Act (CAA) is the comprehensive federal law that regulates air emissions from stationary sources. It authorizes the EPA to establish NAAQS. NAAQS have been set for six common "criteria pollutants": particulate matter; ozone; sulphur dioxide; nitrogen dioxide; carbon monoxide and lead. Under the CAA States are required to adopt enforceable plans to achieve the air quality standards. State plans must also address control emissions that drift across state lines and harm air quality in downwind states. The law calls for new stationary sources to be built with best technology, and allows less stringent standards for existing stationary sources.



National Ambient Air Quality Standards

NAAQS have been set for six common "criteria pollutants": 

- particulate matter

- ozone

- sulphur dioxide

- nitrogen dioxide

- carbon monoxide

- lead


Under the CAA States are required to adopt enforceable plans to achieve the air quality standards. State plans must also address control emissions that

drift across state lines and harm air quality in downwind states. The law calls for new stationary sources to be built with best technology, and allows less stringent standards for existing stationary sources.



Criterian Pollutants

Major Sources and Area Sources

As described by the EPA, Section 112 of the Clean Air Act addresses emissions of hazardous air pollutants. The 1990 Clean Air Act Amendments revised Section 112 to require issuance of technology-based standards for major sources and certain area sources. "Major sources" are defined as a stationary source or group of stationary  sources that emit or have the potential to emit 10 tonnes per year or more of a hazardous air pollutant or 25 tonnes per year or more of a combination of hazardous air pollutants. An "area source" is any stationary source that is not a major source. Though emissions from individual area sources are often relatively small, collectively their emissions can be of concern - particularly where large numbers of sources are located in heavily populated areas.

Maximum Achievable Control Technology

For major sources, Section 112 requires that EPA establish emission standards that require the maximum degree of reduction in emissions. These emission standards are commonly referred to as "maximum achievable control technology" or "MACT" standards. Eight years after the technology-based MACT standards are issued for a source category EPA is required to review those standards to determine whether any residual risk exists for that source category and, if necessary, revise the standards to address such risk.



Menu of Control Measures

The Menu of Control Measures (MCM) provides state, local and tribal air agencies with the existing emission reduction measures as well as relevant information concerning the efficiency and cost effectiveness of the measures. Each agency will be able to use this information in developing emission reduction strategies to assure they attain and maintain the National Ambient Air Quality Standards.





China’s State Council released its Action Plan for Air Pollution Prevention and Control (Action Plan) on 12 September 2013 The Action Plan sets the road map for air pollution control for the five years with a major focus on three key regions:

  • Beijing-Tianjin-Hebei area (Jing-Jin-Ji)
  • Yangtze River Delta (Shanghai area - YRD)
  • Pearl River Delta (Guangdong - PRD)


Action plan



The Air (Prevention and Control of Pollution) Act was passed by Parliament in 1981. The first ambient air quality standards were adopted in 1982 by the Central Pollution Control Board (CPCB) and revised in 1994 and again in 2009.

Agencies responsible for air quality standard creation and monitoring include CPCB and several State Pollution Control Boards (SPCBs).

All of these entities fall under the control of the Ministry of Environment and Forest (MoEF).

Air act CPCB MoEF



Latin America

Latin America

According to a 2012 report by the Clean Air Institute approximately two thirds of the Latin American countries have National Ambient Air Quality Standards.

In particular, La Paz (Bolivia) is notable for having local standards in line with WHO guidelines

CIA report