Answer:
VOCs (volatile organic compounds)
Explanation:
VOCs are organic chemicals whose base is carbon and evaporate at room temperature and pressure generating vapors, which can be precursors of ozone in the atmosphere. In addition to carbon, hydrogen, fluorine, oxygen, chlorine, bromine, nitrogen or sulfur can be found in its composition.
They have volatile, fat-soluble, toxic and flammable properties (in their meanings of risks). On the other hand they are very good solvents and very effective for dissolving paints, and for degreasing materials.
VOCs come from different natural and artificial sources, although their greatest production is carried out in industrial activities.
Activities where it is possible to find VOCs
:
- Paints and varnishes
- Footwear industry (for paints, solvents and glues)
- Steel industry (degreasing parts using solvents)
- Wood industry (lacquer and varnish solvent: turpentine, toluene)
- Cosmetic industry (as dispersant)
- Pharmaceutical industry
- Dry cleaning industry
A large part of the volatile organic compounds present in the atmosphere come from a natural origin of both the decomposition of organic matter (such as methane), by ruminants (methane as well), and of plant origin such as essential oils and saponins constituted by terpenes.
They have a seemingly contradictory double slope, on the one hand as stratospheric ozone destroyers and on the other hand as tropospheric ozone precursors.
As ozone destroyers, Volatile Organic Compounds can influence the degradation of the ozone layer such as 1,1,1-trichloroethane and carbon tetrachloride. The Kyoto and Montreal protocol contemplate actions to reduce the emissions of these compounds into the atmosphere so as to avoid their effect on stratospheric ozone.
