What type of substance is it?
Total VOCs are a large group of liquids and gases many of which are colourless and odourless. The liquids easily vaporise at room temperature - i.e. they are 'volatile'. VOCs are of general concern because of their ability to react with other pollutants (such as nitrogen oxides) in the lower atmosphere to form ozone. High concentrations of ozone at ground level can harm human health, damage crops and affect materials such as rubber. Some VOCs may be directly harmful to human health (e.g. as carcinogens), contribute to global warming (e.g. methane) or destroy stratospheric ozone needed to shield the earth's surface from harmful ultra violet radiation (such as methyl bromide).
How is it released?
Paints, natural gas, petrol, road transport and industrial processes are the major sources of these compounds, however some are also produced in by natural biological processes.
Detailed information
Scientific name:
Total VOCs
Other names:
Total VOC is the generic term for the sum of all Volatile Organic Compounds. The group includes individual VOCs such as methane, benzene, polycyclic aromatic hydrocarbons (PAHs) and 1,3-butadiene
CAS Number:
(not available)
VOCs are often grouped into methane (CH4) and other non-methane VOCs (often called NMVOCs). VOCs also include the group of compounds called polycyclic aromatic hydrocarbons (PAHs) and Dioxins.
Some VOCs are used as solvents for industrial processes, paints and varnishes. Methane is the major component of natural gas, which is used as a domestic and industrial fuel.
A group of chemicals that contain the element carbon in their molecular structure - i.e. they are 'organic'. They easily vaporise at room temperature and most of them have no colour or smell. VOCs include the following chemical groups: alcohols, aldehydes, alkanes, aromatics, halocarbons and ketones and halogenated derivatives of these substances.
Where is it released?
The main sources of methane are leaks from natural gas supplies. Other VOCs are released principally from the burning of fossil fuels, in particular the burning of petrol in road transport. VOCs are often present in solvents, for example in paints and aerosol sprays. Dry cleaning, the production of alcoholic drinks and arable farming are less significant sources of release. Some VOCs are also produced naturally by trees and other plants, making up around 3% of total emissions. The smell associated with conifer forests is due to the release of natural VOC compounds from the needles and resin.
Local environmental effects
Many VOCs are involved in reactions that form ground-level ozone, which can damage to crops and many materials as well as potential effects on human health.
Global environmental effects
Methane contributes to global warming and also reacts with other pollutants to produce ground-level ozone.
Possible health concerns
Excessive exposure to some chemicals in this diverse group may affect health, with the possible effects depending on the particular chemical. The Environment Agency aims to ensure that there is no appreciable risk of adverse effects from environmental exposures.
Legislation
Why was this substance selected for the Pollution Inventory?
Included in : European Pollutant Emission Register (EPER) reporting requirements; United Nations Economic Commission for Europe (UNECE) Convention on Long-Range Transboundary (LRTAP) reporting requirements.
Standard risk phrases for the pure substance
The standard risk phrases provided here are generally those used by suppliers of chemicals to describe substances - for example on packaging materials. The most important source of these phrases are the CHIP Regulations - Chemicals (Hazard Information and Packaging for Supply) - provided by the Health and Safety Executive. Some substances do not have CHIP risk phrases and in these circumstances we have used other risk phrases, the sources of which are indicated.
Because this is a large family of chemicals rather than a single substance, it is not possible to provide risk phrases, which are generally provided for a single substance whose properties can be precisely determined.
Controlling legislation and international agreements
Releases of VOCs are controlled under the UK Pollution Prevention and Control Regulations, which implement the EC Directive on Integrated Pollution Prevention and Control (IPPC). The UK is also committed to reduce VOC emissions under its Air Quality Strategy. The European legislation that controls VOC release includes EC Directive 99/13/EC on Solvents; Directive 84/360/EEC Combating of air pollution from industrial plants and the Ambient Air Quality Daughter Directive. The main international legislation covering VOCs are the UN/ECE Convention on Long-Range Transboundary Air Pollution and Basel Conventions.
These factsheets have been compiled to provide users with information on the Pollution Inventory substances and represent our best efforts to summarise a large number of disparate and sometimes conflicting data sources. We emphasise that this information describes potential hazards rather than actual effects and that the Environment Agency seeks to regulate releases to minimise emissions and hence any risk of detrimental effects occurring.
