Material Insights · Understanding the Material World

Chlorine and Salt

Almost all chlorine is made from salt: electrolysing brine yields chlorine together with caustic soda, using about 1.65 tonnes of salt per tonne of chlorine in theory. Chlor-alkali makers are India's major industrial salt users, yet salt prices hardly affect chlorine, because salt is cheap and power is the main cost.

Chlorine (chemical) and Salt (commodity): 4 relationships.

How they are linked

1. Feedstock: salt brine

Physical flow · Strong · Salt to chlorine

Chlorine is liberated at the anode when sodium chloride brine is electrolysed, and this is the main commercial route, so salt is the main source of chlorine.

  • about 1.65 t salt per tonne of chlorine, from molecular weights before losses
  • about 42% chemical industry share of US salt sales, 2025

In the US about 90% of chemical feedstock salt is used as brine rather than as dry salt. USGS expected world demand for chlor-alkali brine to grow in 2026 while European salt demand was expected to fall with closures of chlor-alkali capacity. For most uses, salt has no economic substitute.

Sources: European Commission JRC; USGS

2. Price link: main use

Cost and price · Weak · Both ways

Chlorine is valued jointly with caustic soda, and its value swings with PVC demand and disposal costs, while salt is a small, stable cost, so the two prices are unrelated.

  • -0.10 monthly change correlation
  • -0.09 12-month change correlation
  • about 60% power share of chlor-alkali production cost in India

Indian producers track the electrochemical unit (ECU) realisation, a weighted value of caustic soda and chlorine, and chlorine has at times had a negative value because of disposal costs. When that happens, plants may cut runs and buy less salt, but salt prices do not move chlorine.

Sources: Material Insights (World Bank, FRED, IMF data); CARE Ratings

3. Gujarat salt base

Geography and ownership · High in India · Chlorine capacity sits beside salt works

Salt is bulky and cheap relative to transport cost, and in India both chlor-alkali plants and salt output are concentrated in Gujarat.

  • 85% Gujarat share of India's salt output, 2021-22
  • about 10.9 Mt salt used by Indian industry, 2021-22

Gujarat combines coastal solar salt, ports and downstream chemical complexes. The Indian Bureau of Mines names chlor-alkali makers as the major industrial consumers of salt, and much of India's chlor-alkali capacity is in Gujarat.

Sources: Indian Bureau of Mines; AL Circle

4. Brine purity for membrane cells

Physical flow · Medium · Cell technology sets salt quality

Membrane cells need purified brine, so salt quality sets the cost of brine treatment and the volume of purification waste.

All Indian chlor-alkali units have moved from mercury to membrane technology. Salt makers have said much Indian salt falls short of chemical industry standards, and IS 797 sets the specification for salt for chemical use.

Sources: European Commission JRC; Indian Bureau of Mines; Business Standard; CARE Ratings

For investors

Key learnings

  1. Salt is the main feedstock for chlorine but a minor cost, so chlorine economics turn on power and the caustic and PVC markets.
  2. Owning brine wells or sitting next to salt works lowers logistics and purification costs, a lasting edge in a commodity business.
  3. Weak chlorine demand can cut chlor-alkali runs and salt demand together, so salt suppliers to chemical plants carry chlorine market risk.

What to track

  • ECU realisation and chlorine netback: A negative chlorine value signals run cuts and lower salt offtake (Quarterly · company results)
  • PVC and chlorine derivative demand: Strong derivative demand supports chlor-alkali operating rates and salt use (Monthly · industry reports, Ministry of Chemicals and Fertilizers)

For policymakers

Key learnings

  1. Chlorine for water treatment and PVC in India depends on Gujarat salt, a concentration worth monitoring for supply security.
  2. Improving industrial salt quality reduces waste brine and treatment chemicals at membrane plants.
  3. Domestic chlor-alkali capacity, and therefore domestic salt, underpins essential uses of chlorine such as water disinfection.

What to track

  • Salt production in Gujarat and monsoon disruption: Lower output or quality tightens chemical salt supply (Annual and seasonal · Indian Bureau of Mines, Salt Commissioner)
  • Chlor-alkali capacity utilisation: Low utilisation signals weak chlorine demand and lower salt use (Quarterly · Alkali Manufacturers Association of India, company results)

India

About 85% of India's salt comes from Gujarat, where much of the country's chlor-alkali capacity is located, so Indian chlorine output rests on one coastal salt belt.

Sources

  1. Price correlation, Material Insights, Material Insights (World Bank, FRED, IMF data)
  2. Best Available Techniques (BAT) Reference Document for the Production of Chlor-alkali, European Commission JRC (2014)
  3. Mineral Commodity Summaries 2026: Salt, USGS (2026)
  4. Indian Minerals Yearbook 2022: Salt, Indian Bureau of Mines (2023)
  5. Industrial salt makers trying to upgrade tech, quality, Business Standard (2016)
  6. Caustic-chlorine industry in India: preparing for a sustainable rebound, CARE Ratings (2021)
  7. Caustic soda plant setup in India: how aluminium growth is reshaping demand, costs and opportunities, AL Circle (2025)