"Total volatile organic compounds" as the group of compounds are not generally used. TVOC is a grouping of a wide range of organic chemical compounds to simplify reporting when these are present in ambient air or emissions. Many substances, such as natural gas, could be classified as volatile organic compounds (VOCs). VOCs are reserved for characterisation of such substances in polluted air, that is, VOCs generally refer to vapours of gases given off by compounds rather than the liquid phase.
Substance name: TVOCs
Synonyms: volatile organic compounds (VOC), non-methane volatile organic compounds (NMVOC).
For the purpose of NPI reporting, Total VOC are defined as any chemical compound based on carbon chains or rings with a vapour pressure greater than 0.01 kPa at 293.15 K (i.e. 20°C), that participate in atmospheric photochemical reactions.
Specifically excluded are:
- carbon monoxide;
- benzene hexachloro;
- n-dibutyl phthalate;
- ethylene glycol;
- di-(2-ethylhexyl) phthalate (DEHP);
- 4,4-methylene bis 2,4 aniline (MOCA);
- Phenol; and
The chemical properties of TVOCs vary widely.
The National Pollutant Inventory (NPI) holds data for all sources of Total volatile organic compounds in Australia.
The health effects depend on the specific composition of the volatile organic compounds (VOCs) present, their concentration and the length of exposure. General effects of exposure to VOCs include: irritation to the eyes, nose and throat; headaches; loss of coordination; nausea; and damage to the liver, kidney and central nervous system. Some VOCs can cause cancer in animals, and some are suspected or are known to cause cancer in humans. Build up of VOCs in indoor environments have been associated with 'sick building syndrome'.
Entering the body
TVOCs are present as a gas or vapour and can enter the body by inhalation.
Exposure to TVOCs occurs by breathing contaminated air. TVOCs may build up in indoor environments as a result of the greater number of sources and lower rates of ventilation.
Workplace exposure standards
Safe Work Australia sets the workplace exposure standards for airborne contaminants. There are no workplace exposure standards for TVOCs
Drinking water guidelines
There is no guideline for TVOCs in the Australian Drinking Water Guidelines.
TVOCs are a known causative agent of photochemical smog. Other environmental effects depend on the composition of the VOCs, the concentration and length of exposure. Some VOCs can have serious effects on animals and plants. Effects may also occur due to secondary impacts, such as the impacts of smog. In liquid form TVOCs may also impact on water and soil.
Entering the environment
TVOCs are carried by air. TVOCs generally refer to compounds in vapour or gas phase.
Where it ends up
TVOCs cover a large number of substances and have varying fates in the environment. TVOCs are degraded by sunlight and eventually break down to simpler compounds. TVOCs are essential for smog formation and they react with oxides of nitrogen to produce ozone.
The following ambient air quality standards were established for photochemical oxidants (as ozone) in 1999:
- Averaging period of 1 hour, a maximum of 0.10 parts per million, with a maximum allowable exceedence of 1 day per year.
- Averaging period of 4 hours, a maximum of 0.08 parts per million, with a maximum allowable exceedence of 1 day per year.
Sources of emissions
TVOCs are produced from a wide range of industrial processes. Significant sources are processes producing or using solvents, paints or use of chemicals. Major point sources of TVOCs in Australian cities are petrol refining, fuel storage and the manufacturing industry, including: industrial machinery, vehicles and transport equipment; iron, steel and other metals; chemical products; wood products; plastic products; paper products; cement, lime and plaster products; ceramic products; oil, fat, petroleum and coal products; glass products; leather products; textiles and woven fabrics; electrical equipment and appliances; and food preparation.
Diffuse sources and industry sources included in diffuse emissions data
TVOCs are released from painted surfaces, fabrics, carpets, printed paper and material, household cleaners, cosmetics and fibreboard products. Petrol stations are significant emitters of TVOCs.
TVOCs are produced from a wide range of biological processes.
TVOCs are produced from vehicle exhausts and from fuel tanks.
TVOCs may be emitted from fabrics, carpets, fibreboard, plastic products, glues, solvents, household cleaners, printed material, methylated spirits, paints and paint products (such as thinners or varnishes), disinfectants, cosmetics, degreasing products, hobby products and in fuels.
Sources used in preparing this information
- Intergovernmental Panel on Climate Change (2001), Climate Change: Working Group 1: The Scientific Basis (Chapter 4), accessed July 2007
- National Pollutant Inventory (1999), Contextual Information.
- National Pollutant Inventory (2006), NPI Definition for Volatile Organic Compounds.
- Office of the Australian Safety and Compensation Council, Exposure Standards: total volatile organic compounds, accessed July 2007.
- Technical Advisory Panel 1999, Final Report to the National Environment Protection Council.
- Safe Work Australia, Workplace exposure standards for airborne contaminants, accessed March 2019.
- National Health and Medical Research Council (NHMRC), Australian Drinking Water Guidelines (2011) - Updated October 2017, accessed May 2018.