Hydrochloric acid: Correlation
Prices it moves with, and why
Hydrochloric acid is mostly a by-product of making vinyl chloride, polyurethanes and other chlorinated chemicals, so supply depends on those markets. It is used in steel pickling, oil wells and water treatment. The series is a broad acids index proxy.
Proxy US PPI: inorganic acids incl. hydrochloric and other index (BLS base period) · monthly, Dec 2008 to Sep 2026There is no free public price for hydrochloric acid itself, so this tab uses the closest public series as a stand-in. Read the numbers as an indication, not as the price of this exact item.
What its price moves with
Selected linkHydrochloric acid and Chlorine
Monthly changes 0.19 little or none correlation 12-month changes 0.59 moderate correlation Last 5 years 0.19 monthly changes Lead or lag −2 mo Hydrochloric acid tends to lead by 2 months (r 0.28) Price function, Dec 2008 to Sep 2026 Hydrochloric acid ≈ 2.16 × (Chlorine)0.66 R² 0.53 On this fit, a 10% higher chlorine price goes with a 6.5% higher hydrochloric acid price over the long run. Units: index (BLS base period) and index (BLS base period).Chart: Hydrochloric acid and Chlorine prices rebased to 100 at Dec 2008, log scale
Both prices rebased to 100 at Dec 2008, on a log scale so equal percentage moves look the same size.Chart: Hydrochloric acid price against Chlorine price, monthly, log scales, with fitted line
Each dot is one month; paler dots are older (2008), darker dots recent (2026); the ringed dot is the latest month. The dashed line is the fitted price function. Both axes are logarithmic.Hydrochloric acid is made from chlorine, either directly or as a by-product of chlorination. The chlorine proxy is a US alkalies and chlorine index; monthly moves correlate at 0.19 and yearly moves at 0.59.
little or none co-movement month to month · 214 months Show chartsMaking MDI and TDI for polyurethanes releases large amounts of hydrochloric acid, so strong foam demand floods the acid market. Monthly moves correlate at 0.24 and yearly moves at 0.71, mostly a shared chemical cycle.
weak co-movement month to month · 214 months Show chartsSteel mills use hydrochloric acid to clean, or pickle, steel sheet before coating, so steel output drives demand, especially for flat products. Monthly moves correlate at 0.18 and yearly moves at 0.52, a shared industrial cycle.
little or none co-movement month to month · 214 months Show chartsShale oil and gas wells are treated with acid to open the rock, so drilling activity raises demand. The proxy is the WTI oil price, and monthly moves correlate at 0.13 and yearly moves at 0.44.
little or none co-movement month to month · 214 months Show chartsVinyl chloride plants produce hydrochloric acid as a by-product and also reuse it, so PVC chain output sets acid supply. The VCM proxy is a broad organics index; monthly moves correlate at 0.25 and yearly moves at 0.64.
weak co-movement month to month · 214 months Show chartsHow to read these numbers
Correlation of monthly changes (the number in the coloured pill) compares how much each price moved, month by month, since 2006 or the first month both series exist. It runs from −1 to +1: near +1 the two usually rise and fall in the same months, near 0 there is no link, and a negative number means they tend to move in opposite directions. Above 0.7 is strong, 0.4 to 0.7 moderate, 0.2 to 0.4 weak.
12-month changes compare year-on-year moves, which shows whether two prices share the same cycles even when the month-to-month noise differs.
Price function is a straight-line fit of the two prices on logarithmic scales: price ≈ k × (partner price)β. β is how much this price moves, in per cent, for a 1% move in the partner over the whole period, and R² is the share of the variation the fit explains. Two prices that both drift up with inflation can fit well without any real link, so read it together with the monthly correlation.
Lead or lag checks whether the monthly correlation is clearly higher when one price is shifted by 1 to 6 months.
Correlation is not cause. The reasons on each card explain the economic link; the numbers show how strongly it has shown up in prices. Proxy series are US producer price indexes or related prices and can blur the real link.
Data: World Bank Commodity Price Data (Pink Sheet), October 2026; US Bureau of Labor Statistics producer price indexes, IMF primary commodity prices and US EIA prices via FRED, Federal Reserve Bank of St. Louis, retrieved November 2026. Calculations by this site.