Market Data

What Moves the Plastic Resin PPI: The Propane-to-Polymer Chain Explained

The PPI for plastic resins tracks producer prices for the polyethylene, polypropylene and PVC that feed U.S. molders. Here is exactly what it measures and the natural-gas and oil feedstocks that push it around.

The Bureau of Labor Statistics' Producer Price Index for Plastic Resins and Materials measures the average change in prices U.S. producers receive for resins like polyethylene and PVC. It reads 319.37 on a 1982=100 base as of May 2026, meaning resin producer prices are about 3.2 times their 1982 level. The index is currently climbing, up about 19.5% from a year ago, and for the injection molders and extruders that buy these materials by the railcar, understanding what sits behind that number is the difference between anticipating a price letter and being surprised by one.

What the index measures, and what it does not

The series captures the selling price at the first commercial transaction: what a resin producer collects at the reactor gate for polyethylene, polypropylene, PVC, polystyrene and the other commodity thermoplastics and thermosets that make up U.S. resin output. It is a revenue-weighted blend of contract and spot business, so it moves more slowly than the spot quotes traders watch but faster than the annual agreements many molders sit on. It excludes freight, distributor markups and compounding, which is why the delivered price on a molder's invoice usually runs above the index level and can lag its turns by a month or two. Because it is a producer price, it is also the number most resin price-adjustment clauses reference, when a supply agreement says prices reset with "the published index," this BLS series or a close cousin is typically the one doing the resetting.

Plastic resins and materials PPI, May 2026: 319.37 index (1982=100). Ranged from 252.96 in Jan 2026 to 319.37 in May 2026 across the archived history; the latest reading sits 100% of the way up that range.

The propane-to-polymer chain

Resin is priced two steps downstream from a gas well. U.S. producers crack ethane and propane, natural-gas liquids separated at Gulf Coast fractionators, into ethylene and propylene, then polymerize those monomers into polyethylene and polypropylene. That chain means the index's raw-material floor is set by NGL benchmarks like Mont Belvieu propane and, indirectly, Henry Hub natural gas, not by crude oil the way it is for naphtha-fed crackers in Europe and Asia. When feedstock costs firm, resin producers push price increases within a quarter; when a new cracker or polymerization line starts up, added supply leans the other way. PVC adds its own wrinkle, chlorine production is electricity-intensive, so power costs matter, and every resin carries energy, catalyst and logistics costs on top of the monomer. The practical takeaway: watch the feedstock benchmarks and the industry's capacity calendar, and this index's next move rarely arrives unannounced.

Resin is priced two steps downstream from a gas well: when ethane and propane move, polyethylene follows within a quarter.

What a move in the index does to a resin budget

Take a mid-size molder consuming 1,200,000 pounds of commodity resin a year at a baseline $0.70 a pound, about $840,000 of annual spend. The index is up about 19.5% from a year ago; if a supply agreement passes that move through, the line item swings by roughly $163,793 a year in the direction the index is heading. That is why the series belongs on a procurement dashboard next to the spot quotes: it is the number that decides whether last year's piece prices still cover this year's material.

Put your part weight, runner share, and the current resin price into the resin cost per part calculator to see what material adds to each piece. Price resin into your parts

Published 2026-07-13.