Guidance on Emissions to Atmosphere

This Guidance Note was issued in 2004 to advise members of the University on the environmental aspects of emissions to the atmosphere.

Contents

1.0Introduction

2.0Pollutants

3.0Legislation

4.0Sources of pollution

5.0Pollution control

1.0INTRODUCTION

1.1The purpose of this guide is to characterise the most prolific pollutants emitted to the atmosphere by the University, their sources and their potential effects upon individuals and the environment. Means of reducing the quantity of emissions released to the atmosphere by the University and current legislation (which must be complied with in order to avoid the risk of prosecution) are also considered.

2.0 POLLUTANTS

2.1Volatile Organic Compounds (VOCs). Volatile organic compounds are compounds that have a high vapour pressure and low water solubility. Many VOCs are man-made chemicals that are used and produced in the manufacture of paints, pharmaceuticals, and refrigerants. VOCs typically are industrial solvents, such as trichloroethylene; fuel oxygenates, such as methyl tert-butyl ether (MTBE) or by-products produced by chlorination in water treatment, such as chloroform. VOCs are often components of petroleum fuels, hydraulic fluids, paint thinners, and dry cleaning agents. Therefore, during the course of many industrial processes, VOCs are released to the atmosphere. Once released, they undergo a series of complex reactions resulting in the formation of ground-level ozone, which is harmful to human health and the environment.Some VOCs are quite harmful, including benzene, polycyclic aromatic hydrocarbons (PAHs) and 1,3-butadiene.Benzene may increase susceptibility to leukaemia, if exposure is maintained over a period of time, and PAHs may be carcinogenic.

2.2Chlorofluorocarbons (CFCs).CFCs, which may be found in existing refrigeration and air-conditioning systems and halons, which may be found in fire-fighting systems, are commonly known as Ozone Depleting Substances (ODS). The depletion of the ozone layer, which prevents harmful solar (UV-B) radiation reaching the Earth's surface, has been caused by the use of these CFC gases.The danger to humans from UV-B radiation includes damage to the eyes; damage to the immune system and over time can lead to development of skin cancers.

2.3 Greenhouse gases.The atmospheric accumulation of certain gases (the greenhouse gases), produced primarily from burning fossil fuels to generate power, are changing the Earth’s energy balance so that global warming occurs, which may lead to other effects such as a global rise in sea levels. Evidence indicates that in the future, instances of heat related summer deaths may increase and there may also be an increase in fatalities by major disasters caused by gales and coastal flooding.The chief gas contributing to this effect is carbon dioxide, as well as methane, nitrous oxide, hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride.

2.4Particulate matter (PM10).Particles with a diameter of 10 microns (PM10) are the most hazardous of fine particles that can damage human health (dependent on the chemical composition of the particulates), even at concentrations previously thought to be unimportant.PM10 are composed of a wide range of materials from a variety of sources, including:

  • Primary particles arising from combustion processes
  • Secondary particles, mainly sulphate and nitrate formed by chemical reactions in the atmosphere
  • Coarse particles composing of suspended soils and dusts, sea salt, biological particles and particles from construction work

PM10 is among the most harmful of all air pollutants. When inhaled these particles evade the respiratory system's natural defences and lodge deep in the lungs.

Health problems begin as the body reacts to these foreign particles. PM10 can increase the number and severity of asthma attacks, cause or aggravate bronchitis and other lung diseases, and reduce the body's ability to fight infections.Although particulate matter can cause health problems for everyone, children, the elderly, exercising adults, and those suffering from asthma or bronchitis are especially vulnerable to PM10's adverse health effects. Also, recent studies have linked PM10 exposure to the premature death of people who already have heart and lung disease, especially the elderly.

2.5Lead.In the mid-1980s, the main source of lead emissions was identified as traffic, as a result of which, the lead content of petrol is now controlled by legislation.However, although this has vastly reduced the lead concentration in the air, lead still affects air quality in urban areas and along heavily travelled motorways. The effects of lead poisoning may be displayed as chronic effects on the nervous system (especially in children), acute abdominal pain, kidney damage, high blood pressure and many others.

2.6 Sulphur dioxide.Sulphur dioxide is emitted to the atmosphere when fossil fuels are burnt primarily to generate power. It reacts with the water vapour already present, so that precipitation has enhanced acidity.This results in the acidification of receiving waters and consequent damage to ecosystems, especially lakes and forests.Acid rain also accelerates the weathering of building materials.Effects on humans indicate that exposure for asthmatics is significantly more damaging than for other people and premature death through heart disease and bronchitis has been known to occur as a result of severe exposure to sulphur dioxide.

2.7Ground level ozone.Ozone is a secondary pollutant, not directly emitted from manmade sources in any significant quantities.It is formed in the lower atmosphere by the sunlight-initiated oxidation of VOCs in the presence of nitrogen oxides.Ozone measured at a particular location may be the result of a reaction that took place hundreds of kilometres away in the recent past.Evidence suggests that not only does it affect people with impaired respiratory systems, but healthy adults and children as well, and at fairly low concentrations.

Ozone is the prime ingredient of smog in cities and other areas of the country. It interferes with the ability of plants to produce and store food, so that growth, reproduction and overall plant health are compromised.

2.8Carbon monoxide.Carbon monoxide is a product of incomplete burning of hydrocarbon-based fuels and is emitted by vehicles.It primarily affects the air quality in urban areas with heavy traffic.It inhibits the blood’s ability to carry oxygen to body tissues, including vital organs such as the heart and brain, which may lead to drowsiness or even asphyxiation at very high concentrations. It reacts with other pollutants to produce ground-level ozone.

2.9Nitrogen oxides.Nitrogen oxides (NOx) is a collective term used to refer to nitric oxide (NO) and nitrogen dioxide (NO2). Nitrogen oxides are produced from combustion processes from nitrogen in the air and to a lesser extent from nitrogen in fuels. Nitric oxide is rapidly converted to nitrogen dioxide in the air by reaction with ozone and other oxidants. The main source of emissions in the UK is road traffic.

Both nitric oxide and nitrogen dioxide are toxic. Nitrogen dioxide can irritate the lungs and lower resistance to respiratory infections such as influenza. Continued or frequent exposure to concentrations that are typically much higher than those normally found in the atmosphere may cause increased incidence of acute respiratory illness in children.

3.0LEGISLATION

3.1Integrated Pollution Prevention and Control (IPPC).In October 1996, the EuropeanCommission published a Directive on Integrated Pollution Prevention and Control (IPPC). This was introduced into England and Wales by the Pollution Prevention and Control (PPC) Regulations 2000.All sites with listed activities have until 2007 to comply with this legislation.

The IPPC Directive is designed to prevent, reduce and eliminate pollution (of all natures) at source through the efficient use of natural resources.It is intended to help operators of such premises to move towards greater environmental sustainability.

It will replace the current UK system of Integrated Pollution and Control (IPC),

and contains three parts:

  • Part A(1) - This is a permitting system regulating emissions to the air, land and water of potentially more polluting processes. The Environment Agency is the regulator.
  • Part A(2) - This is a permitting system regulating emissions to the air, land and water of processes with a lesser potential to pollute. The Local Authority is the regulator.
  • Part B - This regime covers processes with a lesser potential to pollute. Only emissions to the air are regulated. The Local Authority is the regulator.

Parts A(1) and A(2) will replace the IPC regime of Part 1 of the Environmental Protection Act 1990 and will apply to a wider range of industries. These industries include all installations that are currently regulated under IPC, some installations currently regulated under Local Air Pollution Control (LAPC), and some installations that are not currently under either regime such as landfill sites, intensive agriculture, large pig and poultry units, and food and drink manufacturers. Parts A(1) and A(2) aim to achieve a higher level of environmental protection as a whole and take into account other factors, not covered by IPC, such as waste avoidance or minimisation, energy efficiency, accident avoidance and minimisation of noise, heat and vibrations. Part A(2) may sometimes be referred to as LA-IPPC.

Part B is also known as Local Air Pollution Prevention and Control (LAPPC) and this will replace the older LAPC regime.

It requires operators of relevant installations to apply for authorisation permits, if they do not already hold them, to continue legally operating.Currently, however, there are no known processes within the University which require authorisation to comply with this legislation.Yet, there is a requirement for individuals to be aware of it should there be a change in systems of work in the future.

3.2The Environment Act 1995.The Environment Act 1995 introduced the requirement to establish the National Air Quality Strategy (NAQS), which set new Air Quality Objectives (AQOs), to be met by 2005, for each of the following pollutants:

Table 1: Air Quality Objectives

Pollutant / Standard / Objective for 2005
Benzene / 5ppb running annual mean / 5ppb running annual mean
1,3-butadiene / 1ppb running annual mean / 1ppb running annual mean
Carbon monoxide / 10ppm running 8 hour mean / 10ppm running 8 hour mean
Lead / 0.5µg/m3 annual mean / 0.5µg/m3 annual mean
Nitrogen dioxide / 150ppb - one hour mean
21ppb - annual mean / 150ppb - one hour mean
21ppb - annual mean
PM10 (particulate matter) / 50µg/m3 running 24 hour mean / 50µg/m3 running 24 hour mean
(measured as 99th percentile)
Sulphur dioxide / 100ppb - 15 minute mean / 100ppb - 15 minute mean
(measured as 99.9th percentile)
Ozone / 50ppb running 8 hour mean / 50ppb running 8 hour mean
(measured as 97th percentile)

Under the provisions of the Act, local authorities have the duty to review the air quality in their areas where AQOs are being breached or are at risk of being breached.They may do this by designating (Local) Air Quality Management Areas (AQMAs) to remedy any problems.Currently, Cambridge City does not fall into this category.

3.3The Solvents Emissions Directive (SED).Solvents are regulated by EU Council Directive 1999/13/EC, the Solvents Emissions Directive, which was enacted into Pt 1 of the Environmental Protection Act 1990 and the Pollution Prevention and Control Regulations 2000 in March 2002.This Directive sets Emission Limit Values (ELVs) for VOCs from the use of organic solvents, and its purpose is:

  • To reduce air pollution by reducing releases of volatile organic compounds to the environment;
  • To require safer substitutes for solvents known to be carcinogens, mutagens, or toxic. It is also a prerequisite of the COSHH regulations to substitute wherever reasonably practicable.

Generally, processes or sites that operate above the solvent consumption threshold will need to either:

  • Meet an ELV in waste gases and a fugitive emission limit value; or
  • Meet the total ELV; or
  • Implement a solvent reduction scheme to reduce emissions from the installation equal to those that would be achieved by meeting the total emission limit value.

However, there are stricter requirements for those activities using potentially more harmful substances such as halogenated VOCs, or VOCs that are classified as carcinogenic, mutagenic or toxic to reproduction.

3.4Regulation on Ozone Depleting Substances.A new EU regulation which came into force on 01 Oct 2000, Regulation on Ozone Depleting Substances 2037/2000, banned production and use of the substances, and aids to speed up their removal.

Controlled substances for supply and use bans are CFCs, carbon tetrachloride, 1,1,1-trichlorethane, halons, hydrobromofluorocarbons and other fully halogenated chlorofluorocarbons.

3.5The Kyoto Protocol.Under the Kyoto Protocol, the UK has a legally binding target to reduce emissions of the six major greenhouse gases by 12.5%, relative to 1990 levels over the period 2008 – 2012.It has also set a domestic goal to cut carbon dioxide emissions by 20% below 1990 levels by 2010.

3.6The Clean Air Act 1993. The Clean Air Act 1993 allowed Councils to establish Smoke Control Areas to improve air quality by the burning of cleaner fuels in these areas by controlling domestic and industrial smoke. These help the UK to meet air quality standards for sulphur dioxide and particulates set by European law. Under the Environmental Protection Act 1990 smoke emitted from a domestic chimney outside a smoke control area is also covered by nuisance provisions.

3.7Part III Environmental Protection Act 1990 (EPA 90).EPA 90 as amended by the Noise and Statutory Nuisance Act 1993, contains the main legislation on statutory nuisance and allows for action to be taken by either local authorities or individuals.The following are deemed to be statutory nuisances when prejudicial to health, if they become a nuisance or if they interfere with a persons’ legitimate use of land such as neighbours in their homes and gardens:

  • Smoke emitted from premises
  • Fumes or gases from private dwellings
  • Dust, steam, smell or other effluvia from industrial, trade or business premises

4.0SOURCES OF EMISSIONS

4.1Bonfires. Existing legislation does not prohibit bonfires in the UK.However, under certain circumstances, smoke from a bonfire can be considered a statutory nuisance and dealt with under the Environmental Protection Act (EPA)1990.The smoke would have to be sufficient enough to warrant the closing of windows, and the bonfires would have to be a regular occurrence for it to be considered a problem.

Although there are numerous Smokeless Control Areas throughout Cambridge, which are areas where only smokeless fuel can be burnt, the Clean Air Act 1993 does not cover bonfires.Additionally, there may be products or substances in the bonfire which remain unchanged in the ash and may cause contamination of the ground on which the ash lies i.e. wood coated with lead based paint. Alternative means of waste disposal should be considered before planning a bonfire, but should it be deemed to be the ultimate solution, Cambridge City Council should be contacted for advice (tel: 01223 457880) prior to lighting the bonfire.

4.2Boiler houses.The Clean Air Act 1993 allowed the Council to establish Smoke Control Areas to improve air quality by the burning of cleaner fuels in these areas (for further details see: .The Clean Air Act 1993 controls domestic and industrial smoke, and in doing so it helps the UK to meet air quality standards for sulphur dioxide and particulates set by European law. Accordingly, it is an offence to burn fuels which release dark smoke into the atmosphere.For further information see: .

4.3Fume cupboards.A fume cupboard is a type of Local Exhaust Ventilation (LEV), designed to protect individuals from exposure to chemical fumes, gases and chemical aerosols.In the event of a requirement to install a new fume cupboard, guidance should be sought from the Design Guide and Consultants Brief for University Services and Construction Works, published by EM.

The vapours produced by the activities within the ducted fume cupboards are extracted and diluted before being discharged to the atmosphere. This minimises the exposure of airborne contaminants, but misuse or faulty units will drastically reduce the effectiveness of a fume cupboard.They are not to be used as disposal routes for toxic, noxious or flammable waste gases or vapours.

To ensure compliance with EPA 90, all users have a legal requirement to use the best practicable means for preventing the emission into the atmosphere of noxious or offensive substances, and for rendering harmless and inoffensive any substances emitted.

Where possible, noxious emissions should be removed during the course of the experiment by processes such as scrubbing or chemical absorption.

Prior to using a fume cupboard for the first time, all personnel should seek guidance from the University Chemical Safety Adviser.

4.4LEV (other than fume cupboards). The main function of a LEV system is to reduce the concentration of hazardous fumes, dusts and vapours in the working atmosphere to a level where they do not present a risk to the health of workers. Examples of LEV other than fume cupboards include dust collectors, biological safety cabinets, welding hoods, canopy hoods, benchhoods and downdraft hoods. In order to be effective, a LEV system must be well designed and constructed, properly used and maintained in good condition. Performance and efficiency can be impaired by blockages and/or leaks in the ductwork or by the build up of contaminants.

Simple but important points in working with a local exhaust ventilation system include:

  • Do not put yourself between the source and the exhaust hood, as then you will breathe in contaminants as they are drawn into the hood.
  • Do not block the fresh air supply to the workplace.
  • Do not block or obstruct the opening of the exhaust hood.
  • Protect ventilation ducts from damage and holes.
  • Where practicable, work close to the exhaust hood to improve capture of vapours and fumes.
  • Be aware of special precautions required when ventilating potentially explosive or corrosive vapours.
  • Prevent recirculation of exhaust air back into the workplace.
  • Arrange for the inspection of the ventilation system every 14 months to ensure it is operating as designed, and to comply with legislation.

4.5Construction sites.There is the potential for construction sites to produce substantial quantities of particulate matter, i.e. dust, during all phases of the development.Project managers should be aware of this, especially during hot and dry weather spells, and should ensure that dust levels are regularly monitored throughout the working day, as it is difficult to suppress particulate matter when it becomes airborne.It will be necessary to demonstrate that both nuisance dust and fine particle emissions from construction sites are adequately controlled and are within acceptable limits, in order to avoid prosecution under Part III of the Environmental Protection Act 1990 or the IPPC regime.