Argus Media has introduced monthly indices for European ethylene and propylene prices, using weighted spot olefin and feedstock assessments to provide an additional reference for chemical supply contracts. The Argus northwest Europe ethylene and northwest Europe propylene indices incorporate naphtha, propane and butane prices alongside assessments of the relevant finished intermediate chemical. Their values are calculated through a methodology rather than established directly through the conventional monthly contract price negotiations.
The indices were developed following consultation with companies active in the markets and are initially intended to inform existing monthly negotiations. Argus also envisages their use in contracts that combine benchmarks or adopt an alternative to the conventional settlement. That wider application will require agreement between buyers and sellers on how the series enters individual pricing formulas.
Under the longstanding European monthly contract price system, producers and purchasers negotiate reference settlements for ethylene and propylene. The published value can become a starting point for supply agreements in which the parties negotiate discounts, premiums and delivery terms separately. Consequently, the reference settlement and the actual price paid by a manufacturer may move differently as contractual adjustments change.
With fewer companies participating in monthly settlements, Argus says that negotiated discounts have also become more variable. Those developments can weaken the connection between a widely published reference and the commercial terms agreed across the market. A calculation drawing on assessed spot transactions and feedstock markets provides another basis for negotiation, although the resulting value will depend on the weighting and assessment conventions used.
Steam crackers produce ethylene and propylene by heating hydrocarbon feedstocks under controlled conditions, after which the resulting mixture undergoes cooling, compression and separation to recover the light olefins. Product yields are influenced by the feedstock and the operating characteristics of the installation, so changes in naphtha, propane and butane prices can alter the economics of producing the same chemical.
The feedstock flexibility of an individual cracker depends on its furnace configuration and other processing equipment, as well as the relative prices of available hydrocarbons. Changing the input mixture can alter ethylene and propylene yields, energy requirements and the quantities of coproducts recovered. Consequently, even an index incorporating several feedstock assessments cannot reproduce every cost incurred by a particular plant; it provides a market reference rather than a facility-specific production calculation.
Against those operating conditions, the Argus calculations draw information from both sides of the olefins market. Spot ethylene or propylene assessments reflect market conditions for the chemical being sold, while naphtha, propane and butane assessments capture changes in potential production inputs. The published weighting combines these observations into a monthly figure that may respond differently to feedstock price rises and changes in demand for the finished chemical.
A calculated reference can diverge from the negotiated contract settlement during months when spot olefin prices and feedstock costs move in different directions. The result also depends on the prices assessed, the period covered and the methodology used to combine them. Buyers and suppliers considering the series will therefore need to establish whether that pattern of movement corresponds to the exposure built into their existing agreements.
Ethylene is a principal input to polyethylene manufacturing, in which polymerisation produces chains whose structure and properties depend on the catalyst and process conditions. Polymer converters subsequently use polyethylene grades in films, containers, pipes and other manufactured products. A change in monomer procurement cost can influence polymer pricing, although energy consumption, conversion expenditure and commercial terms also affect the cost passed along the supply chain.
Propylene feeds polypropylene production and other chemical processes, creating a comparable connection between an olefin reference and manufacturing costs further downstream. Polypropylene properties vary with polymer structure and processing conditions, allowing production of moulded industrial parts, fibres and packaging materials. The timing of any price adjustment will still be governed by each supply agreement, so different purchasers may experience the same market movement at different points.
If the indices are incorporated into supply contracts, counterparties will need to define the exact series, observation period, publication date, currency and units. Quality specifications, delivery locations and any separate premium or discount must also be accounted for, alongside provisions for an unavailable or corrected price assessment. These terms determine how a published reference becomes a repeatable invoice calculation over the duration of a contract.
That contractual detail extends beyond the initial olefin purchase because polymer contracts can pass monomer costs through an agreed adjustment formula. A manufacturer purchasing plastic resin may consequently encounter the new benchmark through its supplier’s pricing mechanism rather than buying ethylene or propylene directly. The magnitude and timing of the adjustment will reflect the formula and its separate conversion or delivery charges.
The geographical coverage of the indices is northwest Europe, where petrochemical plants and customers use interconnected pipelines, storage and transport infrastructure. Prices for an individual transaction can still depend on delivery terms, product specification and availability at a particular location. Those differences mean a regional reference may need contractual adjustments before it is appropriate to use in purchasing or pricing decisions.
Argus already publishes assessments for the olefin and feedstock markets used in its indices, and the new monthly calculations add a possible reference alongside the negotiated settlement system. Chemical producers and purchasers can compare the series with existing contract prices over successive months before deciding whether to amend their agreements. No compulsory replacement of the present settlement mechanism has been announced.
