Water treatment chemicals: Correlation
Prices it moves with, and why
Water treatment chemicals include coagulants such as alum and ferric chloride, disinfectants like chlorine, polymer flocculants and scale inhibitors. Prices follow mineral and chlor-alkali inputs, and demand is steady, set by municipal and industrial water use.
Price index US PPI: water treating compounds index (BLS base period =100) · monthly, Jan 2006 to Sep 2026What its price moves with
Selected linkWater treatment chemicals and Aluminium
Monthly changes 0.13 little or none correlation 12-month changes 0.34 weak correlation Last 5 years 0.18 monthly changes Lead or lag +3 mo Aluminium tends to lead by 3 months (r 0.22) Price function, Jan 2006 to Sep 2026 Water treatment chemicals ≈ 15.1 × (Aluminium)0.33 R² 0.29 On this fit, a 10% higher aluminium price goes with a 3.2% higher water treatment chemicals price over the long run. Units: index (BLS base period =100) and $/mt. The fit is loose, so treat the function as a rough guide.Chart: Water treatment chemicals and Aluminium prices rebased to 100 at Jan 2006, log scale
Both prices rebased to 100 at Jan 2006, on a log scale so equal percentage moves look the same size.Chart: Water treatment chemicals price against Aluminium price, monthly, log scales, with fitted line
Each dot is one month; paler dots are older (2006), darker dots recent (2026); the ringed dot is the latest month. The dashed line is the fitted price function. Both axes are logarithmic.Alum and polyaluminium chloride, the most used coagulants, are made from aluminium hydroxide or bauxite. The aluminium metal price is only a loose guide: monthly moves correlate at 0.13 and yearly at 0.34, with aluminium leading by about 3 months.
little or none co-movement month to month · 249 months Show chartsFerric chloride and ferric sulphate coagulants are made from scrap iron, iron oxides or steel pickling liquors rather than from iron ore itself. The link is therefore indirect, and monthly moves correlate at -0.09.
little or none co-movement month to month · 249 months Show chartsSulphuric acid dissolves bauxite or iron to make alum and ferric sulphate, and it adjusts water pH. The acid index correlates at 0.09 for monthly moves but 0.69 for yearly moves, showing cost pass-through on annual tenders.
little or none co-movement month to month · 225 months Show chartsChlorine, hypochlorite and chlorine dioxide disinfect drinking water and wastewater, and hydrochloric acid feeds ferric chloride. Against the chlor-alkali proxy, monthly moves correlate at 0.18 and yearly moves at 0.51.
little or none co-movement month to month · 249 months Show chartsPolyacrylamide flocculants, used in wastewater, mining and paper, are made from acrylamide, which is produced from acrylonitrile. Against the organic chemicals proxy, monthly moves correlate at 0.11 but yearly moves at 0.75.
little or none co-movement month to month · 249 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.