Corrosion Protection and Sustainability: Why Are the Two Concepts Inherently Intertwined

Abstract

Corrosion has a significant impact on the economic and environmental sustainability of metal-based infrastructure and products. This position paper explores the intrinsic relationship between corrosion protection and sustainability, examining the economic costs, environmental impacts and technological strategies involved. While corrosion results in resource waste, energy loss, and increased CO₂ emissions, effective corrosion management can extend the service life of metallic components, thus preserving resources and minimizing environmental burden. The approaches such as Total Cost of Ownership (TCO) and Life Cycle Analysis (LCA) can provide a framework for selecting the most cost-efficient and environmentally friendly corrosion protection method in view of the required lifetime. The paper emphasises the crucial role of material selection, design optimization, recyclability and environmentally friendly coatings. Regulatory pressures and new trends such as machine learning are also discussed. Achieving sustainability goals requires greater awareness, education, interdisciplinary collaboration, and continued innovation in corrosion protection strategies.

1. Metals and Economical and Environmental Cost of Corrosion

For over 5000 years, since the Bronze Age, humans have utilized metals in daily activities. We have mastered techniques to extract, purify, alloy, cast, forge, heat treat, and machine metals to achieve desired properties like size, shape, hardness, strength, and conductivity. Metals are vital in many applications: they provide strength and durability in construction, while in transportation, including cars and airplanes, metals ensure safety and efficiency through lightweight designs. Additionally, metals are essential in agricultural machinery, enhancing productivity through tools that withstand heavy-duty use. In domestic settings, metal appliances contribute to functionality and longevity, while electrical wiring and circuit boards are vital for modern technology, enabling power distribution, energy storage and communication. Taken as a whole, metal parts are indispensable in creating the infrastructure and tools that define our modern existence.

Aside from noble metals like gold, platinum, and palladium, which have highly positive electrode potentials, most technically important metals naturally oxidize to form stable compounds such as oxides, sulphides, or carbonates. These compounds demonstrate greater thermodynamic stability, meaning that energy input is required to extract the metals from their oxidized forms in ores [1,2]. Corrosion then refers to the undesired oxidation of metals leading to the formation of corrosion products that often share a chemical composition similar to, or identical to, the original metal ores [1,2].

In 2023, the global production of primary metals was approximately 1904 million tonnes of steel [3], 71 million tonnes for aluminium [4], and 22 million tonnes for copper [5]. These quantities increase from year to year due to further development. Corrosion significantly impacts the economy, costing 3–4% of global GDP directly and up to 6% or even more when indirect costs are considered [6,7,8,9]. It includes the cost of replacement, repair, production loss, corrosion protection, amongst other effects [10]. Repairs and replacements for corroded structures and products are obviously energy intensive. Nowadays, researchers all over the globe recognize corrosion as both an environmental and sustainability challenge. It causes infrastructure degradation, premature replacement, and resource waste, contributing to carbon emissions. New primary resources are required and all steps in the process of their mining, transport, reduction, and manufacture cause CO₂ emissions [11]. Iannuzzi and Frankel concluded that approximately 15 to 33% of annual steel production is allocated to replacing corroded steel, accounting for 1.6–3.4% of global CO₂ emissions in 2021 [12]. Although these values are based on rather broad estimates and historic data, it does not alter the main conclusions of this analysis. If current practices do not improve, the CO₂ emissions tied to the replacement of corroded steel will even increase. This underscores that corrosion science and improving corrosion management are key to sustainability: extending the service life of components through more corrosion resistant and sustainable materials and protective strategies can conserve resources and reduce greenhouse gas emissions.

2. Corrosion Protection Strategies

The goal of corrosion protection is to ensure that the rate of corrosion degradation will not control the overall lifetime of metallic structures. It is not intended to stop corrosion fully as such a goal would be both unrealistic and pointless. In the long term, thermodynamic driving forces will eventually turn all metallic objects to corrosion products. The time frame is the key issue in controlling the trade-off here [13]. The corrosion resistance needs to correspond to the expected moral and physical lifetime expectancy.

Engineering materials differ widely in corrosion resistance, and these differences play a significant role in sustainability metrics such as carbon footprint, material efficiency, and service life. Materials with superior corrosion resistance often have higher embodied energy compared to those more susceptible to corrosion, so the sustainability benefit of their extended service life must outweigh the initial energy and carbon investment [14]. For example, it is estimated that production of steel requires only 7 kWh/kg, whereas it is 49 kWh/kg for aluminum [15]. Nowadays, hybrid material designs, including a protective coating of a metal substrate or a polymer liner inside a metal pipe, are increasingly used to combine the durability of polymeric and ceramic materials with the strength, formability and recyclability of metals, demonstrating the multi-faceted approach needed to balance corrosion performance with sustainability [16,17,18]. Establishing such “cradle to the grave” considerations are essential for designing corrosion protection measures. But we need to close the circle and consider a “cradle to the cradle” view. For example, steel is almost completely recyclable with recycling rates exceeding 80–90% [19,20,21]. Even though steel corrodes, the material loop can be closed to a large extent by recycling scrap.

Another crucial issue in corrosion protection is the prediction of the expected lifetime. Especially in view of safety, as accurate as possible estimation of the period of time when a structure or product is safe is as important as the actual protection. While uniform corrosion leads to gradual thinning manageable by planned maintenance, irregular forms of corrosion are less predictable. For example, pitting corrosion and stress corrosion cracking in alloys like stainless steel or aluminium in chloride-rich environments can cause sudden failures [22,23,24,25]. Corrosion fatigue of alloys used in aircraft, wind turbine blades, and similar components can reduce their lifespan, necessitating frequent replacements [26,27,28]. Understanding these degradation mechanisms and addressing them through proper measures such as material selection, coatings, and cathodic protection is therefore pivotal to extending service life. Thanks to centuries of empirical search and decades of systematic scientific research, there is now a battery of methods for corrosion control available. We have learned a lot about creating efficient barriers between the metal surface and the corrosive environment in the form of metallic, organic, or other coatings, selecting metals with proven resistance, applying external cathodic or anodic current turning the metal surface into an immune or passive state, designing parts in a way to avoid accumulation of corrosive species, and applying efficient corrosion inhibitors [1]. Use of corrosion monitoring able to provide real-time information about actual situation and thus apply immediate countermeasures is also growing rapidly [29,30].

The corrosion behaviour of each material class must be considered alongside its production footprint and end-of-life management. Sustainable designs aim to use sufficient corrosion resistance to meet the required lifespan while minimizing environmental impact. Indeed, determining the optimal method for corrosion protection is complex; it requires consideration of metal composition, structural geometry, application environment, associated failure risks, and anticipated lifetime. The level of knowledge also strongly varies over particular technical fields. In aerospace, automotive, or petrochemical industries, corrosion engineers are naturally members of construction and maintenance teams, and the available corrosion protection knowledge is efficiently implied in the design of parts or the whole assembly and reflected in operating rules. The former two fields have also invested enormous means into developing trustable tools of corrosion testing to make sure that any new material or design would work properly in service. In contrast, the building and food processing industries still often contact corrosion engineers only after a problem occurs, which results in significantly higher costs and unnecessary losses. It is well documented that the application of a proper corrosion protection approach in the design phase is preferable because it is the least costly. It is no surprise then that economists estimate that 15 to 35% of the worldwide corrosion losses could be avoided if only all already known corrosion protection insights were properly applied [6,11,31].

A good corrosion protection system can help us obtain the most from metal at the lowest economic and environmental cost. It is easy to both underprotect and overprotect a structure. Each corrosion protection method has a certain cost, advantages, and disadvantages. This is schematically demonstrated in Figure 1 [31]. Inefficient corrosion protection leads to high corrective, repair, and replacement cost, whereas a too expensive anticorrosion approach is wasteful.

The convergence of machine learning and predictive maintenance algorithms—coupled with real-time sensor data and cloud-based analysis—has advanced our capabilities in early corrosion detection and failure prediction in recent years. Machine learning models such as deep neural networks or ensemble algorithms are nowadays applied to analyze corrosion data and environmental factors [32,33,34]. These approaches are used to forecast corrosion rates and structural degradation, particularly when modeling corrosion progression as a time-series prediction problem with real-time sensor inputs [35]. The improved accuracy of corrosion forecasting directly enhances risk assessment and lifecycle management, as data-driven insights support improved risk-based inspection planning and more accurate remaining life predictions, helping extend asset lifespans while preventing failures.

To design a corrosion protection system that ensures the minimum overall cost of corrosion, knowledge of corrosion mechanisms and experience with both good practice and failures are needed. The former approach is typically provided by corrosion science. Corrosion scientists are at the forefront of the search for new and original corrosion protection methods or trying to gain a deep understanding into the underlying mechanisms. The role of a corrosion engineer is to wear dirty boots and look for solutions to imminent problems, often based on a combination of fundamental understanding and empirical knowledge. In an ideal situation, there is a close link between the two: corrosion engineer identifying a novel problem and bringing it to light, a corrosion scientist obtaining a proper explanation, and both testing immediate and long-term solutions.

3. Total Cost of Ownership

Achieving sustainability in corrosion management requires a holistic, life cycle perspective. Selecting materials or protection strategies involves trade-offs between initial embodied impacts and long-term durability. The most sustainable choice is generally highly context dependent. Relatively recently, two concepts entered the field of corrosion protection. Total Cost of Ownership (TCO) is a common-sense approach that turned into a useful tool in the design of corrosion protection. There is indeed a cost and service lifetime difference if a fence is made of nonprotected carbon steel, zinc-coated steel, zinc-coated and painted steel, or stainless steel. The concept considers not only the investment costs but all associated costs incurred during the use such as repair, lost production, environmental, maintenance and other costs of available solutions and allows for selection of the optimal one in view of the planned service life [36,37]. For a decade, zinc-coated steel can be fully acceptable, whereas a 50-year lifetime expectancy can hardly be attained without combining metallic and organic coating layers. Some simplified data serving as a highly generalized example are given in

Table 1. Relative lifetime and cost of selected corrosion protection measures; data from [39].

Material	Expected Lifetime, Years	Relative Price Per Sheet of 1 m2, 1 mm Thick	Price Per m2 and Year
Carbon steel	3–5	1	0.20–0.30
Painted steel	10+	1.3–2	0.13–0.20
Zinc-coated steel	10+	1.8	0.18
Zinc-coated and painted steel	30+	2–3	0.01–0.07
Stainless steel AISI 304	50+	11–20	0.22–0.40

. They imply that (1) even no corrosion protection can be an option if a very short service life is required and (2) some corrosion protection means can simply be too expensive for a given application. However, it needs to be pointed out that TCO analyses require in practice integration with sensitivity assessments, discount rates, maintenance schedules, failure risk modelling, and uncertainties of input data on service life projections and maintenance costs as all these factors can affect material selection decisions [38].

An example in Figure 2 schematically compares the price of a storage tank installed in a marine climate made of (1) low-corrosion-resistant metal requiring protection with organic paint with the expected lifetime of 25 years and (2) metal resistant to corrosion without any additional corrosion protection. After the 25-year period, the degraded paint needs to be removed by sand blasting and the tank repainted. Although the investment cost is higher for the tank made of the corrosion resistant alloy, savings on the paint application compensates it, and if a 100-year service life is required, the initially more expensive solution is preferable.

4. Life Cycle Analysis

Obviously, achieving sustainability in corrosion protection involves balancing the initial carbon investment in superior materials and corrosion protection measures against the later carbon expenditure for maintenance and replacements. A newer concept, Life Cycle Analysis (LCA), focuses on the environmental impact of human activities. In a minute manner, it looks into all steps of material production, treatment, transport, installation, maintenance, and end-of-the-life operations to obtain as precise as possible image of the cumulative environmental impact [40,41,42,43]. When the formal concept of sustainability was introduced in the late twentieth century as a response to environmental degradation and resource depletion, it was of interest to few only. Slowly but steadily, it grew into a major topic of global discussion. The number of people, institutions, and companies recognising it as a fully relevant if not even principal concern of decision-making keeps increasing.

For example, in the oil and gas industry, LCA can be used to compare a carbon steel pipeline with regular inhibitor injection and replacement after 20 years, against a corrosion-resistant alloy pipeline that lasts over 40 years without inhibitors. The outcome depends on the specific environmental and application conditions and the frequency of required interventions. In such a case, a moderate approach such as using carbon steel with high-performance coating and occasional cathodic protection (CP) can provide a balanced solution. This method avoids the significant initial impact of expensive highly corrosion-resistant alloys while reducing the need for frequent repairs in unprotected systems. The implementation of CP itself adds another facet to the sustainability picture. Spending a small amount of energy on CP over time is more carbon-efficient than the impact of major repairs or reconstruction, in particular when using electric energy generated from a renewable source [14].

Evidently, any corrosion protection action requires energy and resources, therefore increasing the environmental burden. However, if such an action significantly prolongs the useful life of the product, the total result is highly desirable from a sustainability point of view. If a bridge with neglected corrosion protection is replaced every 20 years instead of investing some additional resources into reliable corrosion protection, it cannot be considered as a wise choice. A study by M. Gagné explored the life cycle cost and performance for steel bridges in marine and industrial environments, considering a three-layer paint system composed of a zinc-rich primer, epoxy intermediate, and polyurethane topcoat [44]. The performed LCA is based on a “cradle-to-grave” approach, including raw material extraction and coating production, surface preparation and application, scheduled maintenance and recoating, end-of-life removal and disposal. The findings showed that these coatings provided 14–20 years of protection before maintenance was needed and offered lower TCO over a 45-year span, despite higher initial environmental impact. This research emphasizes how LCA helps balance long-term sustainability and cost in infrastructure maintenance.

It needs to be noted that the LCA concept is still rather young and thus constantly developing. Consequently, parallel studies on the same subject may provide contrasting outputs due to selection of the methodology (process-based, economic input–output-based, and hybrid-based) and entry data collection [45,46]. In addition, different scopes are being applied. Some studies use a “cradle-to-grave” approach, while others include recycling, reuse, and remanufacturing within a “cradle-to-cradle” framework to address aspects of the circular economy. Finally, data availability for particular corrosion protection measures is still limited.

5. Other Environmental, Social and End-of-The Life Considerations

The above-discussed considerations are leading infrastructure owners to evaluate life cycle carbon metrics alongside cost and safety when selecting corrosion mitigation strategies. This trend has been embraced early by the corrosion community as the corrosion protection and sustainability goals are intrinsically aligned. Sustainable development aims to meet the needs of the present without compromising the ability of future generations to meet their own needs [47]. Corrosion protection ensures the long-term durability of infrastructure, buildings, and other critical assets essential for future generations. As corroded structures need to be replaced, new raw metal extraction is required with a variety of negative impacts on the environment. In addition, the whole production chain of new materials requires energy. Beyond carbon and energy, recyclability and toxicity are important sustainability metrics in material selection for corrosion resistance. Corrosion products are not necessarily harmful, but copper, nickel, and other metals oxidize to species that can contaminate soil, water, and air, posing risks to ecosystems and human health [48,49,50,51,52]. Not all degraded structures and objects can or are being recycled. For example, a galvanized steel structure can be recycled at the end of its life cycle [53]. Conversely, a fibre-reinforced polymer equivalent may require disposal via landfill or incineration if suitable recycling technologies are not available [54]. Accordingly, despite the composite’s excellent corrosion durability, its end-of-life disposal burden could render it less sustainable overall compared to a protected metal that integrates well into the circular economy. Another consideration is that specific corrosion protection technologies introduce contaminants that hinder recycling. For instance, electronics and batteries often use coatings or corrosion inhibitors containing brominated or fluorinated chemistry that can complicate recycling [55,56,57].

The trend towards environmentally friendly corrosion protection focuses on reducing environmental impact by using coatings that lack persistent organic pollutants and inhibitors free of heavy metals. This ensures that materials can be more safely managed or recycled at the end of their life cycle. The European Union’s REACH regulation has effectively phased out hexavalent chromium for most applications by 2024, reflecting an understanding that the long-term environmental and health risks of chromate-based corrosion protection outweigh its advantages [58]. Such regulatory pressure has driven innovation in alternative solutions. Volatile organic compound (VOC) emission limits have led to using waterborne or high-solid coatings in industrial finishing [59,60]. In the United States, the Toxic Substances Control Act (TSCA) has driven demand for hazardous air pollutant (HAPs)-free corrosion protection systems, particularly in industrial coatings, to comply with stringent air quality standards [61]. In China, the use of short-chain chlorinated paraffins (SCCPs)—once common in metalworking fluids and corrosion-resistant coatings—has been severely restricted under the Measures for the Environmental Management Registration of New Chemical Substances (MEE Order No. 12, formerly MEP Order No. 7), due to their persistence and toxicity [62]. These regulatory constraints are now pushing manufacturers to adopt more environmentally friendly alternatives such as phosphate-free inhibitors, organic corrosion protection agents, and silane-based systems [63]. Another example is the ban on organotin antifouling coatings in the marine industry since the 2000s, which led to the development of copper-based and biocide-free foul-release coatings, which reduce ocean toxin burden [64,65].

These examples illustrate two general observations: first, that regional regulations often require tailored product formulations and corrosion protection technologies to meet local compliance standards; and second, that the pace, complexity, and volume of regulatory updates—the so-called regulatory index—varies significantly between jurisdictions. While the EU tends to lead with comprehensive and precautionary frameworks, the U.S. emphasizes risk-based assessments, and China is rapidly evolving its system with increasing enforcement and localization requirements. For globally operating companies, navigating this dynamic landscape demands both agility and innovation in corrosion protection technologies. Thus, environmental regulations and sustainability goals are reshaping corrosion protection technologies and management, driving innovation toward safer and more sustainable solutions.

Another aspect that needs to be considered is the balance between embodied energy vs. operational energy. Reducing operational energy by lightweighting in the automotive and aerospace industry saves fuel [11,66]. Cleaner heat exchanger surfaces save pumping energy for air conditioning devices [67]. In our efforts to achieve decarbonization, industries started examining the relationship between corrosion control and energy efficiency. In the energy sector itself, sustainable corrosion management ensures reliability of renewable energy assets. For example, a wind turbine that resists corrosion will operate for its full design life, maximizing the clean energy it produces relative to the resources invested. There is thus a direct link between corrosion prevention and resource efficiency.

Corrosion in the context of sustainability also requires considering the full global and social context. While developed countries can invest in costly corrosion-resistant materials and strategies, developing regions typically prolong the lifespan of their infrastructure using more affordable corrosion protection approaches or through maintenance. Each approach involves distinct environmental trade-offs. Knowledge sharing through international standards, best-practice guidelines and scientific societies is helping to bridge these gaps. Organizations such as the International Organization for Standardization (ISO) and Association for Materials Protection and Performance (AMPP), amongst others, have included sustainability in corrosion standards, promoting the extension of the lifespan of structures and the implementation of safe and environmentally friendly practices. Scientific organizations like European Federation of Corrosion (EFC) play an essential role in sharing knowledge and information about corrosion mitigation in different industries, by aiming to advance the science of corrosion and protection of materials by promoting cooperation and educate the next generation of corrosion scientists and engineers.

6. Conclusions and Outlook

Evidently, there is a close relationship between corrosion protection and sustainability. When implemented correctly with consideration for environmental impact, corrosion protection plays a significant role in advancing global sustainability objectives. An integrated approach involving materials science, electrochemistry, environmental science, and policy is needed to further improve corrosion mitigation. Addressing the full life cycle of products requires input from corrosion scientists and engineers. Design and material selection decisions benefit from this perspective, which is likely to increase demand for professionals trained in corrosion-related fields.

Even with the use of advanced artificial intelligence tools, substantial work remains, such as developing complex materials with desirable properties and lower environmental impacts, ensuring durability, and facilitating recyclability at end-of-life. Increasing awareness that corrosion control contributes to environmental stewardship may help conserve resources, reduce waste, and decrease greenhouse gas emissions related to repair and reconstruction activities.