VOCs vs. Natural VOCs – by Bernhard Lembeck
The current hype to ban or at least reduce VOLATILE ORGANIC COMPOUNDS (VOCs) has befallen the paint industry and the paint consumer alike and the latter is probably in need of explanation what VOCs are all about.
We at ProNature also use some VOCs namely: Genuine Gum Turpentine and Orange Peel Oil Gum Turpentine consists mostly of the chemical compound pinene which is a bicyclic terpene also known as a monoterpene. There are two structural isomers found in nature: α-pinene and β- pinene. As the name suggests, both forms are important constituents of pine resin; they are also found in the resins of many other conifers, and more widely in other plants. Both are also used by many insects in their chemical communication system. Orange Peel Oil consists predominantly of another terpene called d-Limonene. d-Limonene is a biodegradable solvent occurring in nature as the main component of peel oil and biodegrades
completely within 28 days. In common with other terpenes, both of above represent a major sink for the undesirable troposheric ozone, removing the smog-forming catalyst nitrogen oxides and consuming ozone at an increased rate at night. While the materials are photo-reactive, the benefits of removing ozone and nitrogen oxides outweigh the negative impact from the formation of hydroxyl radicals. Despite using VOCs (mostly to reduce the viscosity of plant oils and to facilitate faster drying) we do, however, maintain that “our” VOCs are:
· natural and thus would have been in the environment even without our help
· natural VOCs are readily biodegradable
· when used correctly do not effect human health
· do not escape paint films long after the paint appears to be dry
In general it needs to be said that even though dealing with 100% natural compounds care should be taken when using them i.e. always use in a well ventilated area. Natural compounds and paints are not odour and emission free and may cause allergies. Current developments at EnviroTouch aim to completely omit VOCs in its next generation products. And whilst we naturally disclose our VOCs and all other ingredients most of the paint industry continues to hide behind the smoke screen of VOC reduction making people believe that their products are now eco-friendly. We tend to forget that replacing VOCs with water does not automatically make a product eco-friendly and definitely not organic. Acrylics are NOT eco-friendly but ProNature products are as our raw materials, even our VOCs, are sustainable and not derived from crude oil.
For all readers interested in even more information on VOCs we added an excerpt courtesy of Wikipedia, the free encyclopedia. Volatile organic compounds (VOCs) are organic chemical compounds that have high enough vapour pressures under normal conditions to significantly vaporize and enter the atmosphere. A wide range of carbon-based molecules, such as aldehydes, ketones, acetates, and other light hydrocarbons are VOCs. The term often is used in a legal or regulatory context and in such cases the precise definition is a matter of law. These definitions can be contradictory and may contain “loopholes”; e.g. exceptions, exemptions, and exclusions. The United States Environmental Protection Agency defines a VOC as any organic compound that participates in a photoreaction; others believe this definition is very broad and vague as organics that are not volatile in the sense that they vaporize under normal conditions can be considered volatile by this EPA definition. The term may refer both to well characterized organic compounds and to mixtures of variable composition.
Sources of VOCs
The most common VOC is methane, a greenhouse gas sometimes excluded from analysis of other VOCs using the term non-methane VOCs, or NMVOCs. Major worldwide sources of atmospheric methane include wetlands, ruminants such as cows, energy use, rice agriculture, landfills, and burning biomass such as wood. Methane is the primary component of natural gas. Common artificial VOCs include paint thinners, dry-cleaning solvents, and most constituents of petroleum fuels (e.g. gasoline and natural gas).
Trees are also an important biological source of VOC; it is known that they emit large amounts of VOCs, especially isoprene and terpenes. Another significant source of VOC emission is crude oil tanking. Both during offloading and loading of crude oil tankers VOC are released to the atmosphere. Lately, there has been an environmental focus on this issue resulting in improved VOC handling on newer tankers, and crude oil loading terminals. Considered a factor in indoor air quality issues such as sick building syndrome, VOCs are generated by photocopiers, carpets, and furnishings as they are used or when components oxidize. One irritant, formaldehyde, is present in hundreds of office components, including wood and laminated furniture, shelving, and wall covers. It also evaporates from paints, varnishes, and chemicals used for sealing and finishing walls. Tobacco smoke can contribute high levels of VOCs.
VOCs including halogenides and sulfides are emitted through human respiration, and formaldehyde is emitted at a lower rate from the surface of the human body.
Vapours of VOCs escaping into the air contribute to air pollution. VOCs are an important outdoor air pollutant. In this field they are often divided into the separate categories of methane ((CH4)2) and non-methane (NMVOCs). Methane is an extremely efficient greenhouse gas which contributes to enhance global warming. Other hydrocarbon VOCs are also significant greenhouse gases via their role in creating ozone and in prolonging the life of methane in the atmosphere, although the effect varies depending on local air quality. Within the NMVOCs, the aromatic compounds Benzene, Toluene and Xylene are suspected carcinogens and may lead to leukemia through prolonged exposure. Some VOCs also react with nitrogen oxides in the air in the presence of sunlight to form ozone.
Although ozone is beneficial in the upper atmosphere because it absorbs UV thus protecting humans, plants, and animals from exposure to dangerous solar radiation, it poses a health threat in the lower atmosphere by causing respiratory problems. In addition, high concentrations of low-level ozone can damage crops and buildings.
Contribution to indoor air pollution Many VOCs found around the house, such as paint strippers and wood preservatives, contribute to sick building syndrome because of their high vapour pressure. VOCs are often used in paint, carpet backing, plastics, and cosmetics. The United States Environmental Protection Agency (EPA) has found concentrations of VOCs in indoor air to be 2 to 5 times greater than in outdoor air. Natural VOCs represent around 80% of the total VOC emissions in the world. The volatile organic compounds and nitrogen oxides that form ozone come from both natural and human activities. Industrial development and motor vehicles are not the only source of air pollution. Natural VOC emissions are a much larger part of total VOC emissions than natural NOx emissions are of total NOx emissions. Additionally, isoprene, which accounts for the largest portion of biogenic VOCs, is highly reactive and one of the most effective VOCs in producing ozone. Natural volatile organic compounds are emitted primarily from forested lands. Natural VOC emissions increase with higher temperatures and intense sunlight. Deciduous trees cause higher emissions than evergreens, but large evergreen forests can have significant emissions. Farming areas are relatively minor sources of emissions of nitrogen oxides in the Mid-Atlantic region. Soil temperature and land use influence the amount of nitrogen emissions produced by organisms in the soil. Natural emissions of nitrogen oxides (NOx) are higher in agricultural areas than in urbanized areas. As noted on page 25, below, however, natural sources account for only about 3% of the total emissions of NOx in the mid-Atlantic region. Because of natural emissions of nitrogen oxides and volatile organic compounds, some ozone is present even in the absence of human activities. Scientists estimate that an average natural background ozone concentration is 25 to 45 parts per billion. This is much lower than the current ozone standard of 125 parts per billion. Thus, natural emissions by themselves would not cause unhealthy ozone levels.