T4 is the IMDG Code Chapter 6.7 portable tank instruction for non-hazardous liquids that ride at 2.65 bar test pressure with a bottom-outlet restricted to solids. Cargo population: edible and non-edible oils, animal fats, paraffin liquids. Palm oil, sunflower oil, soybean oil, coconut oil, rapeseed oil, animal tallow, fish oil. The South-East-Asia palm-oil trade rotates a large dedicated T4 fleet between Malaysian and Indonesian refineries and the global edible-oil market.
What T4 is built for
The IMDG DGL assigns T4 to non-hazardous oils and fats. None of these have UN numbers in the conventional dangerous-goods sense, so the assignment is via the non-DG annex of the IMDG portable-tank table. The cargoes cluster around food-grade requirements (FDA 21 CFR 177, EU 1935/2004, Kosher OU/Kof-K, Halal JAKIM/MUI/HMC), so a typical T4 build is a dedicated food-grade fleet entry rather than a rotating chemical tank.
Construction and materials
316L stainless cylinder, 6 mm reference-steel shell, polyurethane foam insulation 50 to 100 mm, aluminium or GRP cladding. Steam coils are usually fitted because most edible oils need heating to remain liquid through ocean transit: palm oil melts at 35 deg C, coconut oil at 24 deg C, beef tallow at 40 to 50 deg C. The coil layout matches T11 chemical builds (8 to 12 longitudinal stainless coils, 6.5 to 13 m2 of heating area). Manlid hinged or low-profile for food-grade hygienic access.
The “solids only” bottom-outlet rule rarely applies in practice for liquid oils. Operators ship oils through the top via dip-pipe or through a bottom-outlet stack designed for food-grade discharge. The IMDG rule is interpreted to mean the tank must be capable of safe top-discharge if mandated; most fleets fit both routes for operational flexibility.
When T4 is the right choice
T4 is the right tank for dedicated food-grade oil service. Stolt Tank Containers operates the largest dedicated food-grade fleet; Hillebrand-Gori specialises in wine, spirits, and beer in T11-spec equipment that overlaps T4 capability. The food-grade certification regime (FDA 21 CFR 177, EU 1935/2004 + 10/2011, USDA, Kosher, Halal) is what distinguishes a T4 food-grade booking from a generic T4 chemical booking, not the IMDG plate.
When T4 is the wrong choice
T4 is the wrong tank for any DG cargo (Class 3 flammables, Class 8 corrosives, Class 6.1 toxics). It is also the wrong tank for cargoes that need a higher MAWP (vapour-pressure-driven liquids with vapour pressure above 1.5 bar at 50 deg C). Most non-edible oils can ship in T1 (lower test pressure) or T11 (higher test pressure); the T4 specifically signals that the operator has booked a food-grade dedicated fleet entry.
How a T4 food-grade booking is verified
Pre-loading inspection covers the food-grade certification documents (FDA, EU 1935/2004, Kosher / Halal where applicable), the EFTCO Food Cleaning Standard ECD (P15 CIP cleaning protocol with documented riboflavin or TOC swab), and the dedicated-fleet history confirming the tank has not carried chemical cargo. Cleaning costs run higher than standard ECD: USD 600 to 1,500 for between-cargo food-grade cleaning, vs USD 200 to 600 for routine non-DG chemical cleaning. The cost is part of the per-tonne economics of food-grade oil shipping.