Product overview
LPG is composed mainly of propane (C3) and butane (C4). Because it becomes liquid under moderate pressure or when chilled, it can be stored and moved compactly and then returned to gas at the point of use. It is recovered both from natural gas processing and as a refinery product.
Commercial grades are defined by their propane and butane balance and by limits on heavier components, sulphur and residue. The mix is chosen for the climate and application, since propane and butane vaporise at different temperatures.
Typical specifications
| Product | Commercial propane, commercial butane or propane-butane mix |
|---|---|
| Composition | predominantly C3 / C4 per grade |
| Vapour pressure | grade dependent (higher for propane) |
| Total sulphur | typically below 50–185 mg/kg per grade |
| Copper strip corrosion | Class 1 |
| Residue on evaporation | limited per specification |
| Free water | none |
| Reference standards | EN 589 / ASTM D1835 and contract grade |
Indicative typical values shown for orientation only. Exact quality is cargo-dependent and the final contractual specification, as confirmed in the sales agreement and verified by independent inspection, prevails.
Commercial relevance and typical uses
LPG is used for domestic and commercial cooking and heating, as an automotive fuel (autogas), and as a feedstock in petrochemical production, notably for propylene and ethylene. Demand for heating grades is seasonal, rising in colder months.
The propane-to-butane ratio is selected for the end use and climate: propane vaporises at lower temperatures and suits colder conditions, while butane carries more energy per unit volume where temperatures allow.
Quality and independent inspection
LPG is sampled and tested under pressure by an independent inspector against the agreed composition, vapour pressure, sulphur and corrosion limits, and quantity is determined from calibrated pressurised or refrigerated tanks. 3FB coordinates this appointment; firms such as SGS and Intertek are referenced as examples of inspectors active in the trade, not as partners.
Because LPG is handled as a pressurised liquid, sampling and measurement follow specific procedures. See inspection and how independent inspection works.
Shipping and logistics
LPG is carried in pressurised, semi-refrigerated or fully refrigerated gas carriers depending on parcel size and voyage, and handled through dedicated terminals. 3FB trades on FOB terms, with the buyer arranging the gas carrier, and on CIF terms, with 3FB arranging freight and insurance to discharge, as explained in FOB versus CIF.
A delivery window is agreed as a laycan, and vessel type is matched to the terminal's pressurised or refrigerated handling. See shipping and logistics.
Trade documentation
An LPG cargo is accompanied by the bill of lading, certificate of origin, certificate of quality and certificate of quantity from the inspector, and the commercial invoice, with payment commonly under a documentary letter of credit.
The bill of lading and letter of credit notes explain these instruments.
Buyer inquiry process
To request an indication, state the grade (commercial propane, commercial butane or the required mix), the volume, the delivery terms (FOB or CIF with the terminal), the laycan, the vessel or terminal handling type and the payment instrument. The desk reviews feasibility and responds with an indicative offer, subject to confirmation.
KYC and compliance review precede any definitive agreement. Start at the trading desk.