The results of an LCA study provide a comprehensive overview of the environmental impact of a product or process. Within this analysis, different impact categories are distinguished, each describing a specific type of environmental impact. In this article, we explain more about the impact category Acidification. We will clarify what this category entails and how to interpret the results.
Context: what are impact categories in an LCA?
When conducting a life cycle assessment (LCA), the environmental impact of a product or process is assessed. This impact is divided into different impact categories, such as climate change, land use, ecotoxicity, and acidification.
Each impact category has its own indicator to quantify its environmental impact. Acidification is measured in SO₂ equivalents (SO₂-eq), which express the level of acidification caused by emissions such as sulfur dioxide (SO₂), nitrogen oxides (NOₓ), and ammonia (NH₃).
Want to learn more about impact categories? Read our article here.
What does the impact category acidification mean?
The impact category Acidification describes the acidifying effects of certain emissions into the air. These emissions undergo chemical reactions in the atmosphere before being deposited on soil and water.
Acidification can occur due to the release of sulfur and nitrogen compounds (for example, from the combustion of fossil fuels), which react with water vapor in the atmosphere, leading to acid rain.
Acidification has several negative environmental consequences, such as:
- Soil acidification – A decrease in soil pH, which disrupts nutrient uptake in plants and damages ecosystems.
- Water acidification – Increased acidity in rivers and lakes, threatening biodiversity, particularly fish populations and aquatic ecosystems.
- Damage to vegetation and forests – Acid rain affects leaves and needles, disrupting photosynthesis.
- Accelerated corrosion – Infrastructure, buildings, and artworks can deteriorate more quickly due to acidifying substances.
The impact of acidification
The impact of acidification is typically expressed in SO₂ equivalents (SO₂-eq), meaning that different acidifying substances are converted based on their effect relative to sulfur dioxide (SO₂), which is used as the standard reference. Some LCA methodologies, such as the Product Environmental Footprint (PEF) method, express acidification in moles of atomic hydrogen (mol H⁺ eq).
What falls under the impact category Acidification?
The impact category Acidification can be further divided into three subcategories:
Acidification – airborne emissions
This category focuses on the emission of air pollutants that cause acidification, such as:
- Sulfur dioxide (SO₂) from fossil fuel combustion and industry.
- Nitrogen oxides (NOₓ) from combustion processes, including transportation and power plants.
- Ammonia (NH₃) from agriculture, particularly livestock farming and fertilizers.
These substances react with water vapor in the atmosphere, forming acid deposition (such as sulfuric acid and nitric acid).
Acidification – terrestrial (soil acidification)
This subcategory includes processes that directly contribute to soil acidification, such as:
- Excessive nitrogen deposition from fertilizers and agricultural activities.
- The loss of basic minerals in the soil, leading to nutrient depletion.
- Acid drainage from mining activities, which mobilizes heavy metals.
Acidification – aquatic (water acidification)
This subcategory focuses on the impact of acidifying substances on water bodies, including:
- Run-off of acidifying substances from agriculture and industry into rivers and lakes.
- The breakdown of buffering minerals in water, leading to lower pH levels.
- Damage to aquatic ecosystems, such as the decline of fish populations.
What can you gain from insights into your environmental impact in this impact category?
By understanding your environmental impact in the impact category acidification, you can develop strategies to reduce your impact and operate more sustainably.
Optimising business processes
An LCA identifies which processes or components contribute the most to acidification. With these insights, you can take action, such as:
- Switching to low-sulfur fuels to reduce SO₂ emissions.
- Implementing more efficient combustion techniques to lower NOₓ emissions.
- Installing air scrubbers in industrial facilities to filter acidifying emissions.
Reducing environmental impact
You can take targeted steps to mitigate acidification by focusing on:
- Reducing nitrogen use in agriculture through precision fertilization.
- Using more sustainable energy sources, such as wind and solar energy, instead of fossil fuels.
- Establishing circular production chains that generate fewer emissions.
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Lowering your environmental impact can also create market opportunities. Sustainable production processes and low acidification effects can provide a competitive advantage in tenders and environmental certifications.
Regulatory compliance
- Improved compliance with emission standards: Many environmental regulations set limits on acidifying emissions. An LCA helps monitor and meet these standards.
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The impact category Acidification in an LCA helps you understand the effects of acidification on soil, water, and air. This insight can be used to reduce emissions, make business processes more sustainable, and comply with environmental regulations.
Want to know how your product scores on acidification, and what steps you can take to reduce your impact? Contact us!
