Volatile organic compound

Volatile organic compounds (VOCs) in paint are considered harmful to the environment and especially for people who work with them on a regular basis. Exposure to VOCs has been related to organic solvent syndrome, although this relation has been somewhat controversial.[15] In the US, environmental regulations, consumer demand, and advances in technology led to the development of low-VOC and zero-VOC paints and finishes. These new paints are widely available and meet or exceed the old high-VOC products in performance and cost-effectiveness while having significantly less impact on human and environmental health. Volatile organic compounds (VOCs) are organic chemicals that have a high vapor pressure at ordinary, room-temperature conditions. Their high vapor pressure results from a low boiling point, which causes large numbers of molecules to evaporate or sublimate from the liquid or solid form of the compound and enter the surrounding air. An example is formaldehyde, with a boiling point of Ц19 ∞C (Ц2 ∞F), slowly exiting paint and getting into the air. VOCs are numerous, varied, and ubiquitous. They include both human-made and naturally occurring chemical compounds. Most scents or odors are of VOCs. VOCs play an important role in communication between plants. [1] Some VOCs are dangerous to human health or cause harm to the environment. Anthropogenic VOCs are regulated by law, especially indoors, where concentrations are the highest. Harmful VOCs are typically not acutely toxic, but instead have compounding long-term health effects. Because the concentrations are usually low and the symptoms slow to develop, research into VOCs and their effects is difficult. Formaldehyde is an organic ompound with the formula CH2O. It is the simplest form of aldehyde, hence its systematic name methanal. The common name of the substance comes from its similarity and relation to formic acid. A gas at room temperature, formaldehyde is colorless and has a characteristic pungent, irritating odor. It is an important precursor to many other chemical compounds, especially for polymers. In 2005, annual world production of formaldehyde was estimated to be 23 million tonnes (50 billion pounds).[3] Commercial solutions of formaldehyde in water, commonly called formalin, were formerly used as disinfectants and for preservation of biological specimens. In view of its widespread use, toxicity and volatility, exposure to formaldehyde is a significant consideration for human health.[4] On 10 June 2011, the US National Toxicology Program described formaldehyde as "known to be a human carcinogen". Formaldehyde is more complicated than many simple carbon compounds because it adopts different forms. One important derivative is the cyclic trimer metaformaldehyde or trioxane (CH2O)3. There is also an infinite polymer called paraformaldehyde. When dissolved in water, formaldehyde combines with water to form methanediol or methylene glycol H2C(OH)2. The diol also exists in equilibrium with a series of oligomers (short polymers), depending on the concentration and temperature. A saturated water solution, that contains about 40% formaldehyde by volume or 37% by mass, is called "100% formalin". A small amount of stabilizer, such as methanol, is usually added to limit oxidation and polymerization. A typical commercial grade formalin may contain 10Ц12% methanol in addition to various metallic impurities.