VOCs in industry: how to manage them

When we think of air pollution, many people picture industrial chimneys, cars, or particulate matter. However, there is a group of pollutants that often go unnoticed because they are not always visible or detectable by smell, yet they can play a very significant role in air quality: Volatile Organic Compounds, known as VOCs.

In recent years, the term has gained visibility in industrial sectors, municipal environmental management, and air quality policy design, but what exactly are VOCs?

What are VOCs?

Volatile Organic Compounds (VOCs) are carbon-based organic substances that evaporate easily and are released into the atmosphere during the use of solvents, formulation mixtures, cleaning, application, or drying processes.

The MITECO approach describes them as organic compounds that are in a gaseous state at room temperature or have high volatility, and it adopts a common technical criterion: considering compounds with a vapor pressure ≥ 0.01 kPa at 20 ºC (or equivalent volatility) as VOCs.

Volatile is not just an adjective; it is a physical-chemical property that explains why, in industry, VOCs appear primarily where there is:

• Application of coatings (painting, varnishing, lacquering).
• Dry cleaning.
• Adhesives and resins.
• Printing and graphic arts.
• Degreasing and solvent cleaning.
• Mixing and formulation.
• Drying (ovens, tunnels, booths).

Many VOC emissions do not exit through chimneys as visible smoke; they are evaporations and diffuse emissions that occur during the normal operation of a facility.

Why are they a problem for air quality?

In the presence of sunlight and nitrogen oxides (NOx), VOCs can contribute to the formation of tropospheric ozone, or ground-level ozone. This is important because, while ozone in the stratosphere protects us from solar radiation, ground-level ozone is a pollutant that can have negative effects on health and vegetation.

That is why VOC management is not just about odors or chemical products; it is about air quality on a territorial scale, and this is where VOCs become especially relevant from an environmental perspective.

Furthermore, these processes are linked to the phenomenon known as Photochemical smog, that polluting haze that can appear over certain cities or industrial areas under specific conditions.

Solvent Management Plan

If your industrial activity involves the use of organic solvents, there is a high probability that you are generating VOC emissions. This is where the Solvent Management Plan comes in; this document is the tool that allows you to translate solvent usage into emissions, with precise figures and full traceability.

In Spain, the primary legislation is Royal Decree 117/2003 of January 31, on the limitation of emissions of volatile organic compounds due to the use of solvents in certain activities, which regulates the limitation of VOC emissions resulting from the use of organic solvents in specific activities and facilities.

Although many companies view it as merely an administrative document, the Solvent Management Plan is essentially a mass balance—a framework for calculating solvent inputs and outputs over a specific period (usually a calendar year). This is explained directly in the MITECO guide . The goal of the plan is to verify compliance with VOC emission limits and keep them under control, rather than just "reducing for the sake of it." Furthermore, the Andalusian Regional Government technical guide clearly states that the Solvent Management Plan allows for the identification of solvent inputs and outputs, thereby quantifying emissions, and the Community of Madrid summarizes it clearly: it allows for the calculation of fugitive emissions, which are otherwise difficult to determine.

In industry, VOC emissions are not just what comes out of a chimney; often, the biggest problem lies in fugitive emissions, such as:

• Evaporation during application or drying.
• Equipment cleaning.
• Transfers.
• Downtime with open containers.
• Storage leaks.
• Purges, spills, or product impregnation.

If you don't have a Solvent Management Plan, these emissions go unnoticed. That is why this plan is crucial; it forces you to answer the following question with data: of Where is the solvent I buy going?

Royal Decree 117/2003 specifies which facilities are required to comply, based on two criteria:

• The activity is listed in Annex I.
• Consumption thresholds in Annex II are exceeded.

Calculated precisely through a Solvent Management Plan, the plan breaks down solvent usage into:

Inputs

• Solvent in raw materials (paints, inks, adhesives, cleaners).
• Solvent recovered or reused on-site.

Outputs

• Captured and treated emissions (if an abatement system is in place).
• Fugitive emissions (evaporation into the environment).
• Solvent in the final product.
• Solvent-containing waste (rags, sludge, contaminated containers).
• Solvent destroyed or treated off-site.

This allows you to obtain indicators that help manage your facility, such as actual consumption, efficiency, or the percentage of VOCs emitted and retained.

So, how does a Solvent Management Plan benefit a company?

1. Regulatory compliance: Royal Decree 117/2003 aims to prevent or reduce the environmental and health effects of VOC emissions, and the Solvent Management Plan is the technical document that allows you to justify compliance with quantitative data.
2. Process control: In many industries, the Solvent Management Plan can help identify leaks caused by:
   • Operational habits.
   • Anomalous consumption.
   • Excessive cleaning.
   • Evaporation losses.
3. Identifying improvements: reducing VOCs often means reducing solvent consumption, which leads to monetary savings, environmental benefits, and better regulatory compliance.

VOCs are a perfect example of an environmental issue that often goes unnoticed until limits are reached, inspections occur, or air quality impacts arise. This is the reality:

VOCs are a clear example of how air pollution is not always visible. Sometimes the challenge lies in what cannot be perceived with the naked eye but has real consequences for air quality, health, regulatory compliance, and the environmental improvement of industries and cities.

At Ideas Medioambientales, we help you develop and justify your Solvent Management Plan, tailored to your specific operations and the framework of RD 117/2003. We work with you to collect data on consumption and raw materials, organize technical information, perform the solvent balance, and document it clearly and robustly for audits, inspections, or environmental procedures.

You might be interested in: Industrial environmental technical staff: regulations, reports, and much more than just paperwork

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