Procurement of 2-propanol (isopropyl alcohol, CAS 67-63-0) across multiple suppliers requires that five quotation variables be normalized before price ranking. The five variables are pricing basis, Incoterms, package configuration, assay specification, and payment tenor. A quote expressed as 1,650 USD/mt FOB Busan with assay 99.5 wt% in 200 L epoxy-phenolic steel drums is not equivalent to a quote of 1.58 USD/kg EXW Rotterdam with assay 99.9 wt% in 1000 L composite IBCs. The difference is not arithmetic only; freight, insurance, customs, tare mass, working capital cost, and analytical safety margin must be placed side by side on a single reference basis.

When the three quotations are ranked by face value only, Quote C appears cheapest per litre. Normalizing Quote C to USD/kg using a density of 0.785 g/cm³ gives approximately 1.97 USD/kg before CIF insurance, customs clearance, and inland haulage. Quote B is already in USD/kg but is on gross mass and must be reduced by the IBC tare; Quote A must be converted from metric ton net to kg and adjusted for freight and insurance. The side-by-side ranking changes once these fields are aligned.

What a Pricing Basis Must Reveal Before an IPA Unit-Price Ranking Can Start

For isopropyl alcohol, the quoted basis normally appears as EXW, FOB, CIF, or DDP with a net or gross mass, and occasionally a wet or dry weight reference. Net weight excludes the package mass; gross weight includes drums, IBCs, pallets, and closures. If a supplier quotes 1,620 USD/mt on gross weight while another quotes 1.72 USD/kg on net weight, the net comparison requires subtraction of tare mass. For a 200 L steel drum shipment, the tare mass per drum is typically 18–22 kg; for a 1000 L IBC, the tare mass may be 55–70 kg. Across 80 drums, a gross-to-net correction of more than 1,400 kg is common. The comparison matrix should specify whether the quote includes pallets, closures, desiccant bags, or nitrogen blanketing fees.

The basis must also state the density reference temperature. Industrial 2-propanol has a density of approximately 0.785 g/cm³ at 20 °C. A volume-based quotation in USD per litre can be converted to USD per kilogram only after the exact density and temperature are fixed. Quotes that omit the density reference temperature can introduce a mass-based comparison error because the same liquid volume carries different mass at 15 °C and 25 °C. Density should be determined by ASTM D4052 or ISO 12185. Without that, the unit-price comparison is not analytically valid.

Incoterms 2020, Freight Allocation, and Transfer of Risk

When an IPA quote is made FOB Busan, the seller delivers on board the vessel and the buyer assumes freight, insurance, and import clearance. A CIF Nhava Sheva quote includes freight and insurance to the named port, but risk transfers on board at the load port under Incoterms 2020. A DDP Monterrey quote pushes import duty, VAT, and inland delivery to the seller. These differences can alter landed cost by 8–15% depending on the route, bunker charges, and terminal handling. In a side-by-side comparison, each Incoterm should be rerated to the same delivery point using a common freight and insurance model; otherwise the ranking will be controlled by logistics rather than product cost.

For bulk isopropanol in ISO tanks, CIF terminology requires careful transfer of risk. Under CIF, insurance must comply with Institute Cargo Clauses (C) unless otherwise specified; for flammable solvents, buyers often require Institute Cargo Clauses (A) plus war and strikes clauses. A supplier quoting CIF without specifying the insurance clause has not fixed the true landed cost. At the 25 m³ ISO tank size, the product value can exceed 30,000 USD, and a cargo loss from contamination or heat damage is not covered by the standard minimum clause. The side-by-side comparison must record the exact Incoterms edition—Incoterms 2020—and the named terminal or port, including whether demurrage is allocated to buyer or seller.

Packaging configuration for 2-propanol changes the quoted unit price through tare mass, disposal, handling, and stowage constraints. Steel drums of 200 L are commonly lined with epoxy-phenolic coatings; if the lining is not specified, rust and iron contamination become a quality risk. Composite IBCs of 1000 L reduce unit handling cost but require bunded storage and compatible gaskets. Bulk ISO tanks of 20 m³ or 25 m³ lower packaging cost per kilogram but require dedicated loading racks, nitrogen padding, and tank compatibility checks. The package comparison should include the UN packaging symbol, closure type, pressure rating, maximum fill level, and palletization. A drum quote may include returnable pallets or not; an IBC quote may include rental and monthly rental after 14 days; a tank quote may include cleaning and heating surcharges. These package-related costs are frequently excluded from the base unit price and must be added before ranking.

UN 1219 allows drum and IBC shipments under Class 3, Packing Group II when closures meet the required vapour pressure integrity. Isopropanol vapour pressure at 20 °C is approximately 4.4 kPa; closures and venting must remain leak-free under the elevated temperature conditions specified in the IMDG Code or ADR. In practice, suppliers offering 1000 L IBCs with standard vented caps may not meet the closed transport requirement on high-ambient-temperature routes. Published data for specific closure performance across all transport lanes is limited, but a supplier quotation should be accepted only after a UN packing certificate and tank test record are supplied for the package line item.

When Assay Specifications Differ by 0.2 Percent, Water and Acidity Move in Parallel

Assay for 2-propanol is usually reported as gas chromatographic purity in weight percent. The common industrial specification is 99.5 wt% minimum; anhydrous grades may specify 99.8 wt% or 99.9 wt% minimum. The difference between 99.5% and 99.9% appears small but changes the residual water, acidity, and non-volatile residue budget. For coatings and cleaning applications, water above 0.2 wt% can reduce solvency, alter drying rate, and leave residue on critical surfaces. For pharmaceutical-grade use, the relevant monograph may set water ≤0.3% and require ethanol, methanol, and benzene limits to be reported. A quotation that states only “IPA 99%” does not identify the analytical test method, the reference temperature, or the allowed impurity envelope.

Industrial isopropanol should be assessed against ASTM D770 for specification compliance, with water by Karl Fischer titration using ASTM D1364, acidity by ASTM D1613, non-volatile residue by ASTM D1353, and density by ASTM D4052. For a resin or coatings manufacturer, water content above 0.2 wt% can reduce compatibility with hydrophobic resins; use of 99.5% material in a moisture-sensitive formulation may require molecular sieve drying or reformulation. For extraction processes, non-volatile residue above 0.001 wt% can concentrate in the final product. A lower-assay quotation is therefore not necessarily lower-cost when downstream drying, distillation, or filtration is required.

Payment Terms, Bank Charges, and Working Capital Cost

A quote at 1,580 USD/mt on letter of credit at sight is not equivalent to the same price on T/T 60 days after bill of lading. A letter of credit adds opening charges, amendment fees, and confirmation charges; a T/T 60-day term means the supplier is financing the buyer. The present-value adjustment should use the buyer’s weighted average cost of capital or the relevant interbank rate. For a 20 m³ tank loaded with approximately 15.7 mt of IPA, a 60-day payment difference at 6% annual interest is approximately 250 USD. The comparison should record for each quotation the bank instrument, the tenor counted from bill of lading or invoice date, the documents required, and the LC confirmation status.

Payment terms also interact with Incoterms and title documents. Under FOB or CIF, a letter of credit may require a negotiable bill of lading, certificate of quality, and certificate of origin. Under EXW, an LC may be structurally incompatible because a carrier-issued truck waybill may not satisfy bank negotiation requirements; cash against documents or a bank-approved waybill structure may be required. A side-by-side comparison that ignores this interaction may select a quote that is commercially unpayable or that hides additional bank charges. Published bank charges for documentary collections and LC confirmation should be obtained from ICC trade finance schedules or the issuing bank, not from the supplier’s quotation.