Market evolution: Caustic soda liquid (CN 281512) — 2015–2025

Introduction

Caustic soda in aqueous solution (CN 281512) is a fundamental inorganic chemical used across a wide range of industries, including alumina refining, pulp and paper, water treatment, and organic chemicals manufacturing. As a bulk commodity produced predominantly via chlor-alkali electrolysis, its trade dynamics are closely tied to energy costs, industrial demand cycles, and the co-product relationship with chlorine.

This report examines the evolution of EU external trade in caustic soda liquid over the period 2015–2025. Over this decade, the EU has undergone a significant structural shift: it transitioned from a marginal net exporter to a notable net importer, import prices have risen steeply, and the geographic composition of trade partners has been substantially reconfigured — all against a backdrop of declining domestic production volumes and a major price shock in 2022 linked to the European energy crisis.

The analysis is based on trade data for CN 281512 reported by the European Union to non-EU partners.

1. From marginal exporter to structural importer: a deteriorating trade balance

The EU's trade balance has swung decisively into deficit

Throughout the period under review, the EU's trade balance for caustic soda liquid has been negative in most years and has widened substantially. In 2015, the trade deficit stood at approximately €89 million. By 2025, it had roughly doubled to around €179 million. The deficit peaked at an estimated €443 million, highlighting the severity of the imbalance in some intermediate years.

The net import reliance ratio — defined as (imports − exports) / production — shifted from −2.0% in 2015 to +4.8% in 2025, confirming that the EU moved from a position of slight self-sufficiency (with a marginal export surplus) to one of measurable dependence on external supply. At its peak, net import reliance reached 13.2%.

Volumes have grown only modestly while values have surged

A striking feature of the period is the divergence between quantity and value trends. EU import volumes rose by only 9.2% (from 1.29 million tonnes to 1.41 million tonnes), while import values jumped by 81.0%. This implies that the average import price increased by 65.8%, from approximately €158 per tonne in 2015 to €262 per tonne in 2025. Similarly, export volumes grew by 23.6% (from 666,000 to 824,000 tonnes), but export values rose by 65.0%, with the unit price climbing from €172 to €230 per tonne (+33.5%).

This price effect reflects several overlapping factors: rising global energy costs (caustic soda production is electricity-intensive), post-pandemic supply chain disruptions, and the structural repricing of European chlor-alkali output following the 2022 energy crisis.

Domestic production volumes have contracted while their value has risen

EU production of caustic soda (measured in kg NaOH) declined from 8.18 billion kg in 2015 to 6.24 billion kg in 2025 — a drop of 23.8%. Yet over the same period, the reported production value rose by 89.1%, from €1.47 billion to €2.78 billion, peaking at €4.93 billion. This further confirms the dominant role of price increases rather than volume growth in driving nominal trade values upward.

The contraction in output likely reflects the permanent closure of older mercury-cell plants under EU environmental regulations, the rising cost of electricity in Europe, and demand-side weakness in certain downstream sectors (e.g., paper and pulp).

2. Geographical realignment of trade flows and rising import concentration

The United States has become the EU's dominant import supplier

The most dramatic shift in the EU's import landscape has been the rise of the United States. US-origin imports surged from €49 million in 2015 to €186 million in 2025 (+279%), making the US by far the EU's largest single supplier of caustic soda liquid by value. At their peak, US imports reached €246 million. This growth reflects the competitive advantage of US chlor-alkali producers, who benefit from lower natural gas and electricity costs.

Norway, the EU's second-largest supplier, also grew its shipments (+34% to €98 million), benefiting from cheap hydropower-based production. By contrast, imports from the United Kingdom collapsed by 65% (from €55 million to €19 million), likely reflecting Brexit-related trade frictions and the UK's own production adjustments.

Chinese imports, while still small in absolute terms in 2025 (€3.1 million), show extraordinary growth from a near-zero base. Their volatility is extremely high (coefficient of variation of 2.24), suggesting sporadic, opportunistic shipments rather than a stable supply relationship. Ukrainian imports have effectively ceased, falling to essentially zero by 2025 — consistent with the disruption of Ukraine's industrial base following the 2022 Russian invasion.

The US import concentration has driven up the overall HHI

The rising dominance of the United States is also reflected in the Herfindahl-Hirschman Index (HHI) for imports by value, which increased from 2,671 in 2015 to 3,351 in 2025 (+25.5%). An HHI above 2,500 is generally considered to indicate a highly concentrated market. The import HHI by volume followed a similar trajectory, rising from 2,724 to 3,519 (+29.2%).

By contrast, the export HHI decreased over the period (from 1,573 to 1,211 for value-based concentration), indicating that EU exporters have diversified their destination markets. This is visible in the growth of exports to Switzerland (+882% to €25 million), the United Kingdom (+261% to €45 million), and Türkiye (+76% to €27 million), while traditional exports to the United States declined by 50%.

EU member-state trade roles reflect industrial geography

Among EU member states, the Netherlands, Belgium, and France are the largest exporters to non-EU partners, consistent with their large chlor-alkali production bases and port infrastructure. Hungary and Belgium show the highest revealed comparative advantage (RSCA of 0.56 and 0.42, respectively, in 2025), indicating strong export specialisation in this product.

On the import side, Finland (€71 million), Italy (€57 million), and Sweden (€46 million) are the largest EU importing member states. The fact that several Nordic countries appear among the top importers — despite Norway being a major supplier — reflects the cross-border integration of Scandinavian chemical supply chains, with Finland and Sweden often lacking sufficient domestic chlor-alkali capacity to meet local demand.

3. The 2022 energy crisis as a structural inflection point

A pronounced price shock centred on 2022

The data clearly identify 2022 as a year of exceptional price disruption. The top shock events detected in the data are:

All three of the most significant shock events are price shocks centred on 2022. This is consistent with the impact of the European energy crisis triggered by Russia's invasion of Ukraine. Since chlor-alkali electrolysis is extremely electricity-intensive, the spike in European power prices in 2022 drove up the marginal cost of EU-produced caustic soda, simultaneously raising both domestic prices and the prices EU producers charged for exports.

The abnormality scores — which measure how far a given observation deviates from its historical trend — are remarkably high for the Bosnia & Herzegovina export shock (413.6), indicating a price movement vastly outside normal variation.

Import prices surged to their highest level in the series

EU import prices peaked in 2022 at approximately €451 per tonne, nearly three times the 2015 level of €158. While prices have since corrected, the 2025 level of €262 per tonne remains 66% above 2015, suggesting a permanent upward repricing rather than a temporary spike.

Similarly, the supplementary unit price (EUR per kg NaOH) for imports rose from €0.30 in 2015 to €0.52 in 2025 (+75%), confirming that the price increase is not merely an artefact of changing product concentration.

Trade intensity has increased while export propensity has edged down

The EU's trade intensity — the ratio of total trade (imports + exports) to domestic production — rose from 15.0% in 2015 to 19.5% in 2025, indicating that the EU economy has become more open to cross-border flows of this product. By contrast, export propensity (exports as a share of production) declined slightly from 9.0% to 8.6%.

The divergence between rising trade intensity and flat-to-declining export propensity is further evidence that the increase in trade openness is driven primarily by growing import dependence rather than by expanding export capacity.

Volatility is concentrated in a handful of partners

The coefficient of variation (CV) of bilateral trade values reveals substantial heterogeneity in partner stability. On the import side, China (CV 2.24), India (1.19), and South Korea (1.23) show extremely high volatility, indicating that trade with these partners is episodic and unreliable. Norway (CV 0.15) and the United States (0.31) are the most stable import partners.

On the export side, Uruguay (CV 2.04), Switzerland (0.96), and South Africa (0.91) show the highest volatility, while Serbia (0.10) and Bosnia & Herzegovina (0.22) are among the most stable — reflecting the integration of Western Balkan markets into EU chemical supply chains.

Conclusion

Over the decade 2015–2025, the EU's external trade in caustic soda liquid has undergone a fundamental structural transformation. The Union has shifted from a position of near self-sufficiency to one of growing import dependence, with the trade deficit approximately doubling and net import reliance rising from −2.0% to +4.8%.

Three interconnected dynamics have driven this evolution. First, EU domestic production has contracted by nearly 24% in volume terms, reflecting the long-term decline of European chlor-alkali capacity under competitive pressure from regions with lower energy costs. Second, import prices have risen by 66%, with a particularly sharp spike during the 2022 energy crisis, permanently repricing the product upward. Third, the import supply base has become more concentrated on the United States, whose share has grown dramatically, while the EU's export destinations have diversified — driven in part by the post-Brexit reorientation of UK-bound flows and growing trade with Western Balkan and Swiss markets.

The 2022 energy crisis stands as the single most important inflection point in the series, producing extreme price shocks across multiple bilateral relationships and accelerating the structural trends already underway. While prices have partially corrected from their 2022 peaks, they remain well above pre-crisis levels, and the EU's underlying dependence on external caustic soda supply appears to be a lasting feature of the market rather than a transient phenomenon.