Volatile Organic Compounds
Volatile organic compounds (VOCs) encompass a very wide range of organic compounds characterized by high vapour pressure at lower temperatures, which gives them significant volatility already at room temperatures. According to the current legislation, a volatile organic compound (VOC) is any organic compound, including a fraction of the creosote, which has, at the temperature of 293.15K a vapour pressure of 0.01 kPa or greater, or the equivalent volatility under the conditions of temperature and pressure under which it is used. This group comprises over 10,000 currently known compounds, such as methane, benzene, xylene, propane and butane.
Although they can be naturally occurring as well, from the legislative viewpoint, the important VOCs are those arising from different anthropogenic activities. They have a wide industrial application, primarily as organic solvents, which means they can be found in many paints, coatings and adhesives – and consequently, in many objects and products we use every day. Typical activities where they are used include printing, paints and coatings manufacture, coating activities, production of construction materials, production of furniture and wood products, as well as dry cleaning. Some of the best-known compounds used for these purposes are acetone, benzene, ethylene glycol, formaldehyde, methylene chloride, perchloroethylene, toluene and xylene. It is important to note that products manufactured in VOC-using processes can often be a source of VOC emissions themselves, in their further use, such as paints, lacquers or adhesives, but also furniture, flooring and hygienic and cosmetic products. Since VOCs evaporate already at room temperatures, they are present in the living and working environment.
Effects on health and the environment
The intensity of health and environmental effects of volatile organic compounds primarily depends on the type of compound, its concentration and exposure time. Long-term indoor exposure can cause fatigue, headache, nausea, eye, nose and throat irritation in sensitive persons, but also damage the central nervous system and other organs. Not all VOCs show harmful health effects, but some can have carcinogenic and mutagenic effects or affect reproduction.
Environmental impacts of volatile organic compounds are primarily seen in the decreased air quality, but they can also be found as water and soil pollutants. In the atmosphere, they lead to the formation of the harmful ozone and photochemical smog in the lower layers of the atmosphere, and contribute to formation of acid rain and greenhouse gases. In the presence of sunlight, VOCs produce ozone by reacting with nitrogen oxides and carbon monoxide. In the troposphere, ozone increases the formation of fine particles in the air, and the mixture of ozone, particles and other gaseous pollutants is known as smog. In addition to lowering visibility, substances in smog can affect the plant health, lowering yields of seeds and pollination efficiency, and they can have harmful effects on respiratory systems of humans and animals.
In the European union, the key legislative instrument for the reduction of industrial emissions of VOCs is the Industrial Emissions Directive (IED) (2010/75/EU), or, more precisely, its Chapter V. This chapter lists the special requirements for industrial installations using volatile organic compounds in their production processes.
Industrial Emissions Directive (IED) largely draws from the previous Directive, the Directive on VOC Emissions from organic solvents (1999/13/EC) adopted in 1999. They differ only in that the provisions, definitions and deadlines prescribed in the previous directive are now harmonized with other IED chapters.
Provisions of Chapter V of the Directive pertain to 20 types of activities which use organic solvents, and operators who manage installations where such activities take place are obliged to undertake all necessary measures to comply with them. Technical provisions pertaining to installations and activities using organic solvents are listed in Annex VII of the Directive.
In the Republic of Serbia, the key document in this field is the Regulation on the list of industrial installations and activities for which volatile organic compounds emissions are controlled, on the values of volatile organic compounds emissions at a certain solvent consumption and total emission limit values, as well as an emissions reduction scheme (“Official Gazette of the RS”, no. 100/11). Implementation of the Regulation began on 1 January 2013, and it prescribes the obligations of operators engaged in one or more of 20 activities relevant for volatile organic compounds emissions, which exceed the prescribed annual thresholds for solvent consumption. All key provisions regarding the list of activities, substitution of certain substances with less hazardous alternatives, selection of a reduction scheme, manner of elaborating an annual solvent mass balance, monitoring and reporting obligations, annual consumption threshold and annual emission limit values for flue gas and emission limit values for fugitives for each activity are all prescribed in the Regulation. The Regulation is available at the website of the Ministry of Environmental Protection:
as well as at the Project website, in the INFO CENTRE/Legislation section.
Obligations of the operators arising from the legislation
In line with the Regulation, operators in the Republic of Serbia, who perform one or more activities using organic solvents and exceed the solvent consumption threshold prescribed in Annex 2 of the Regulation (VOC operators) are obliged to:
- Monitor and submit data to the Environmental Protection Agency, by filling in and submitting a form provided in Annex 3 of the Regulation. The form includes administrative and technical information on the company, activities performed, and quantities and types of used solvents;
- Ensure that volatile organic compound emissions from installations remain within the range of the allowed emission limit values for waste gas and for fugitive emissions, or within total emission limit values prescribed in the Regulation (Annexes 5 and 6 of the VOC Regulation).
Substitution of hazardous substances
Hazardous substances or mixtures that are classified as carcinogenic, mutagenic or toxic for reproduction based on the volatile organic compounds they contain, i.e., those with hazard statements H340, H350, H350i, H360d or H360f, or those with risk phrases R45, R46, R49, R60 or R61 must be substituted, whenever possible, with less harmful substances or mixtures without delay. In addition, operators using compounds with the aforementioned hazard statements or risk phrases must comply, as soon as possible, with emission limit values for such compounds prescribed in Article 8 of the Regulation.
Emission reduction scheme
The operator may decide to apply a reduction scheme to achieve a reduction in emissions to ensure that they comply with the values prescribed in Annex 5 and Annex 6 of the Regulation.
The purpose of a reduction scheme is to allow the operator to achieve, by other means, a reduction in emissions equivalent to the one that would be achieved using emission limit values. This may usually be achieved by substituting solvents with a high content of volatile organic compounds with those that are low-VOC or VOC-free (such as water-based solvents), or by changing the technological process so that the organic solvents are used in far lower quantities, or not used at all.
The reduction scheme should be specifically designed for the particular installation in line with the requirements provided in Annex 7 of the Regulation, i.e., the implementation of these measures should ensure that the prescribed annual emission limit values are not exceeded, in line with the calculation that is a constituent part of this Annex. Operators who decide to apply a reduction scheme are obliged to notify the competent Ministry of that fact and submit the scheme they apply.
Annual solvent mass balance
The installation operator is obliged to elaborate an annual solvent mass balance for organic solvents in line with the procedure from Annex 4 of the Regulation. The purpose of elaborating this balance is to check compliance of VOC emissions from the installations against emission limit values prescribed in Annex 5 and Annex 6, or target emission values prescribed in Annex 7. In addition, based on the calculation of the annual solvent mass balance, the operator may identify opportunities for further consumption decrease. The calculation includes the data on solvent consumption, its reuse, emissions of VOCs into air and water, as well as VOC emissions from waste and final products.
The annual solvent mass balance is elaborated every year for the previous year and kept for two years. VOC operators should regularly submit the data from their annual solvent mass balance to the Environmental Protection Agency. The form that the operators fill in and submit to the Agency, which is in the form of an Excel spreadsheet (VOC Regulation form) is available on the Agency’s website:
At the last page of this table, there is an image that may significantly help operators to understand the definitions from Annex 4 of this Regulation, based on which the annual solvent mass balance is elaborated.