Epichlorohydrin (ECH), CAS 106-89-8, is a chlorinated epoxide intermediate with a normal boiling range of 115–117 °C, a density of 1.18 g/cm³ at 20 °C, and a flash point near 31 °C closed cup. Industrial production follows either the propylene-based allyl chloride route or the glycerin-based dichloropropanol route; both generate a reactive monomer used primarily in liquid epoxy resin, synthetic glycerin, epichlorohydrin elastomer, and wet-strength resin manufacture. Because the feedstock cost positions of these routes are dissimilar, a long-term supply agreement must specify how price will be calculated and how volume obligations affect that price. This article examines the Epichlorohydrin Long-Term Supply Agreement: Price Mechanism & Volume Tier Table and the technical clauses that determine contract reliability.

Spot purchasing cannot provide the quantity security needed by a downstream process operating with limited buffer storage. A contractual mechanism instead links the transaction price to feedstock indices, energy, and a fixed adder, then applies volume tier adjustments to the formula result. The agreement also fixes quality metrics, sampling, logistics, and force majeure terms. In practice, the price clause and the volume tier table are the commercial core; the remaining clauses define operating boundaries.

When Epichlorohydrin Supply Contracts Move Beyond Spot Pricing

Spot ECH values are subject to propylene and chlorine index swings, glycerin import competition, and regional production outages. A buyer whose epoxy resin reactor train consumes ECH at process rates exceeding 1.0 t/h cannot renegotiate pricing after a spot cargo is delayed; substitution is constrained because ECH is reactive and storage requires inhibited, moisture-protected containment. A long-term mechanism allows the buyer to plan reactor campaigns across 30–90 day scheduling windows and gives the seller a committed outlet for capacity. The negotiated formula does not eliminate price risk; it transfers the index basis to published reference prices and reduces negotiation frequency.

In propylene-based ECH supply agreements, the mechanism commonly includes a feedstock index for propylene, a chlorine or caustic chlorine index, an energy adder, and a fixed adder covering labor, maintenance, catalyst, waste disposal, and reverse logistics. For glycerin-based ECH, the feedstock index may be refined glycerin or hydrogen chloride, depending on process configuration. The coefficient applied to each index is not a simple stoichiometric ratio; it is adjusted for yield loss, co-product credit, and plant-specific utility consumption.

How Is a Price Mechanism for ECH Structured?

A contract-grade price mechanism often appears as a formula:

P_ECH = (a × propylene index) + (b × chlorine index) + (c × energy index) + fixed adder,

where a, b, and c are contract-specific coefficients in tonne-per-tonne or MWh-per-tonne terms. The coefficients are validated against mass balance data from the seller’s unit, but exact plant consumption rates are usually confidential. Representative public technology assessments indicate that propylene-route ECH production can consume approximately 0.65–0.70 t propylene and 1.00–1.10 t chlorine per tonne of ECH before yield correction; however, these ranges are starting points rather than contractual values. If the parties cannot agree on coefficient disclosure, the mechanism may use a simpler published ECH spot index minus a tier discount.

Settlement mechanics matter as much as the formula. A quarterly settlement may average the feedstock index for month M-1 or M-2, depending on the agreed lag. A monthly settlement reduces index lag but increases administrative workload. The price basis must state the Incoterms 2020 rule, such as FCA seller’s terminal, CIF buyer’s port, or DDP buyer’s tank, because freight and insurance can alter the effective price by 5–10% on interregional shipments. Currency settlement, often USD or EUR, includes an FX adjustment clause when feedstock indices are published in a different currency.

Price collars, caps, and floors are used selectively. A floor tied to the seller’s variable cost prevents destocking during downcycles, while a ceiling protects the buyer from demand destruction in rising feedstock markets. The numerical boundaries are contract-specific; published data for a universal market standard is limited, so the cap and floor must be audited against actual variable cost and buyer margin data.

Volume Tier Table and Contractual Offtake Mechanics

The volume tier table links the price adjustment to committed annual offtake. In an Epichlorohydrin Long-Term Supply Agreement: Price Mechanism & Volume Tier Table, the tier structure is not only about discounting; it also assigns scheduling priority, storage allocation, and take-or-pay exposure. A representative table is shown below. Published data for specific market-clearing brackets is limited, and the values should be read as negotiation templates rather than fixed market terms.

Under take-or-pay mechanics, a buyer that fails to lift the minimum volume pays the fixed adder on the shortfall; a seller that cannot supply above force majeure may be required to procure replacement ECH and compensate the buyer for the price difference. The higher tiers often require parent guarantees or standby letters of credit because the seller reserves dedicated tank or pipeline capacity. Volume tables should avoid retroactive tier cliffs that create an incentive to inflate annual offtake at year-end; many contracts apply marginal discounts above the threshold or an annual rebate after the tier is confirmed.

Four Parameters Separate Contract-Grade ECH from Technical-Grade Supply

ECH quality clauses in a long-term supply agreement are enforced at unloading. The buyer’s laboratory samples each shipment from a circulation loop or top hatch using closed sampling systems because ECH is toxic and flammable. The core acceptance parameters are assay, water, color, and chlorinated impurities. Representative limits and methods are listed below; actual limits are contract-specific and may be tighter for high-molecular-weight epoxy resin or synthetic glycerin applications.

Off-spec moisture is particularly problematic in epoxy resin polymerization because water consumes sodium hydroxide or amine catalyst and alters the stoichiometric balance. A moisture level above 50 mg/kg can shift the epoxy equivalent weight of the resulting resin, forcing reformulation of the hardener ratio in downstream thermoset applications. Dichloropropanols and other chlorinated impurities can act as chain terminators or introduce hydrolyzable chloride into the resin backbone, reducing electrical insulation properties and corrosion resistance.

ECH is normally moved in insulated stainless steel tanks or lined carbon steel tanks with nitrogen blanketing. Unheated pressure/vacuum vents are avoided where ambient relative humidity exceeds 60%, because atmospheric moisture can raise water content above specification and initiate slow hydrolysis to monochloropropanediol. Unloading pumps are positive-displacement units with mechanical seals selected for low-vapor-loss service; mass flow meters installed in the transfer line provide custody-transfer measurement. Before first fill after a change of grade, the buyer should verify that the seller’s tank has been cleaned and dried to a dew point below −20 °C. Because ECH is classified under CLP (EC) No 1272/2008 as Flam. Liq. 3, Acute Tox. 3, Skin Corr. 1B, Skin Sens. 1, and Carc. 1B, REACH (EC) No 1907/2006 exposure scenarios limit dermal and inhalation routes, and delivery paperwork must include the relevant registration number and updated SDS.

In a continuous liquid epoxy resin unit, ECH and bisphenol-A are charged into a reactor train with excess ECH to control exotherm and molecular weight distribution. The excess ECH is recovered in a wiped-film evaporator under reduced pressure, typically 20–50 kPa absolute, and recycled to the reaction section. The recovered ECH stream may concentrate dichloropropanols and water; therefore the feed specification is more stringent than the pipeline delivery specification if the recovery loop is tightly closed. Production-scale operators tie acceptance to the contractual methods before unloading because a single off-spec barge can alter the reactor mass balance and shift the epoxy equivalent weight outside the target range for BADGE liquid resin.

Synthetic glycerin production hydrolyzes ECH under high-temperature alkali conditions; chloride and water impurities in feed directly affect ion-exchange resin life and final USP-grade chloride limits. Buyers supplying pharmaceutical glycerin lines therefore request a separate certificate of analysis with chloride below 5 mg/kg and water below 50 mg/kg, and may reject material that does not meet those values at the tank truck manifold. Published data for specific plant configurations is limited, but the acceptance principle is consistent across pharmacopeial compliance programs.