What Sustainable Aviation Fuel Actually Is
Sustainable aviation fuel, almost always shortened to SAF, is a drop-in replacement for conventional jet kerosene that is produced from renewable or waste-based feedstocks rather than crude oil. It is blended with standard Jet A-1 fuel at percentages that airlines and cargo operators are increasingly required to meet rather than simply encouraged to pursue, and it is chemically close enough to conventional fuel that it can be used in existing aircraft and airport fuelling infrastructure without engine modifications. Today's SAF is produced mainly from used cooking oil, animal fats, and agricultural or forestry residues through a process called hydroprocessed esters and fatty acids, though a growing slice of future capacity is aimed at synthetic power-to-liquid fuel made by combining captured carbon dioxide with hydrogen produced using renewable electricity. For a sector that has few realistic near-term alternatives to liquid fuel — batteries and hydrogen propulsion remain decades away from long-haul freighter viability — SAF has become the primary lever aviation has for cutting emissions, and it now sits squarely inside conversations about transportation logistics that used to focus almost entirely on ocean freight decarbonization.
Why Regulators Have Moved From Encouragement to Mandate
For years SAF adoption was largely voluntary, driven by individual airline sustainability pledges and corporate customers asking for greener supply chains. That has changed. The European Union's ReFuelEU Aviation regulation now requires a minimum share of SAF in the fuel uplifted at EU airports, starting at a modest percentage in the mid-2020s and stepping up through the 2030s and 2040s toward much higher blending ratios, with fuel suppliers facing penalties for shortfalls. In parallel, the International Civil Aviation Organization's Carbon Offsetting and Reduction Scheme for International Aviation, known as CORSIA, is moving from its earlier voluntary participation phase into a broader phase covering most international routes, and airlines that use SAF can reduce the volume of carbon offsets they would otherwise need to purchase under that scheme. The practical effect of stacking a hard blending mandate on top of a carbon offsetting framework is that air cargo carriers can no longer treat SAF as an optional sustainability add-on. It is becoming a compliance cost baked into the price of operating internationally, in much the same way low-sulphur fuel rules reshaped ocean freight cost structures earlier this decade.
The Production Bottleneck Sitting Behind the Mandates
The uncomfortable reality behind all of this policy momentum is that SAF supply has not caught up with SAF demand. Global SAF production remains a small fraction of total jet fuel consumption, and the feedstocks used to make it — used cooking oil in particular — are also wanted by the renewable diesel industry for road transport, creating direct competition for the same limited raw material pool. Building new dedicated SAF refining capacity requires years of lead time and heavy capital investment, and synthetic e-fuel production is even further from commercial scale. The result is a structural mismatch: blending percentages set by regulation are rising faster than production capacity can comfortably support in several regions, which is precisely the kind of supply-demand imbalance that tends to show up first in price rather than in outright shortages. Some airlines have responded by signing long-term offtake agreements directly with SAF producers to secure future volume and lock in pricing, a sign of how seriously the supply risk is being taken at the corporate level, but these agreements still only cover a fraction of overall fuel demand and do little to change the underlying economics for carriers without similar deals already in place.
What SAF Costs Today, and Who Actually Pays for It
Depending on the feedstock and production pathway, SAF has generally cost somewhere in the range of two to four times as much as conventional jet fuel per tonne, with synthetic e-fuels sitting toward the higher end of that range and waste-oil-based SAF closer to the lower end. Airlines and freighter operators are not absorbing that premium into their own margins at scale — doing so on blending volumes that will only grow over the coming decade simply isn't viable. Instead, the cost is being passed through to customers via SAF-related or environmental fuel surcharges layered on top of the base air waybill rate, a mechanism that will feel familiar to anyone who has watched bunker adjustment factors move on ocean freight invoices. For businesses that rely on air cargo for time-critical shipments, this means the SAF premium is no longer a background policy story — it is starting to appear as a distinct line item on freight quotes.
Conventional Jet Fuel vs. SAF Blends: A Quick Comparison
| Factor | Conventional Jet A-1 | SAF Blend |
|---|---|---|
| Feedstock | Crude oil | Used cooking oil, waste fats, residues, synthetic e-fuels |
| Relative cost per tonne | Baseline | Roughly 2-4x baseline |
| Global supply availability | Abundant | Constrained, ramping slowly |
| Lifecycle emissions | Higher | Up to roughly 80% lower, pathway-dependent |
| Aircraft compatibility | Standard | Drop-in, no engine modification needed |
Belly Capacity vs. Dedicated Freighters: Where the Pressure Lands Hardest
A meaningful share of the world's air cargo, especially on long-haul passenger-heavy routes, still moves as belly cargo underneath scheduled passenger flights rather than aboard dedicated freighter aircraft. That distinction matters for how the SAF cost premium is felt. On a passenger aircraft, the incremental fuel cost can be spread across both ticket revenue and cargo revenue, which softens its impact on any single air cargo booking. Dedicated freighter operators don't have that luxury — their entire revenue base is cargo, so a rising SAF blending requirement translates more directly into a higher cost per kilogram carried. This is worth understanding for shippers choosing between carriers or routings: freighter-heavy lanes and all-cargo carriers may show the SAF surcharge more visibly on their rate sheets than passenger-belly-heavy alternatives serving the same city pair, even though both are ultimately subject to the same underlying blending mandates.
SAF Fits Into a Broader Decarbonization Push Across Transportation Logistics
Air cargo is not decarbonizing in isolation. Ocean carriers are working through their own emissions framework via the International Maritime Organization, road fleets are electrifying at the margins, and rail operators are expanding electrified corridors — all part of the same broader push to bring carbon costs into everyday transportation logistics pricing rather than treating emissions as a free externality. For shippers who move freight across multiple modes, as most import and export businesses ultimately do, this matters because a SAF surcharge on the air leg of a shipment is unlikely to be the only environmental cost showing up on an invoice going forward. A shipment that starts on an ocean vessel, transfers to rail, and finishes on a truck can eventually carry compliance costs at more than one point along that chain. Treating each mode's decarbonization cost as a one-off surprise makes budgeting harder than it needs to be; treating them as a connected, predictable feature of modern transportation logistics — the same way fuel price volatility has always been priced into freight contracts — makes for sounder long-term planning.
What Shippers Booking Air Cargo Should Expect Through 2027
Shippers moving cargo on lanes touching the European Union should expect SAF-related surcharges to become a standard, growing component of air freight quotes as ReFuelEU's blending percentages step up year over year. Other jurisdictions, including the United Kingdom and several markets in Asia, are moving through their own consultation and early-mandate stages, which means the surcharge pattern currently concentrated on Europe-bound lanes is likely to broaden geographically over the next few years rather than staying contained. For time-sensitive freight, the most effective response isn't to avoid air cargo altogether but to work with a forwarder who books across multiple carriers and can compare how each one structures its environmental surcharges, since the pass-through mechanics and rates are not standardized industry-wide. It is also worth watching how individual airports and countries define their own SAF obligations, since a shipment that transits through a hub with strict local blending rules can pick up surcharge exposure even when neither the origin nor the final destination has a mandate of its own — transshipment routing, not just the headline origin-destination pair, increasingly factors into the final landed cost of an air cargo shipment. For freight where a few extra days genuinely don't matter, shifting some volume toward ocean freight or a hybrid sea-air routing remains a sensible way to manage rising per-kilogram air cargo costs without abandoning speed entirely on the shipments that actually need it. This kind of blended-mode thinking is increasingly central to transportation logistics planning generally, not just for air cargo specifically, as fuel-related compliance costs spread across modes.
How RR Brothers and Logistics Can Help
RR Brothers and Logistics books air cargo across a network of carrier partners on lanes connecting China to India, Europe, the Middle East and beyond, which gives clients real visibility into how SAF-related surcharges vary by carrier and routing rather than accepting a single quote at face value. Where speed is essential, our air freight forwarding service is built to find the most cost-effective compliant routing available; where it isn't, our multimodal and sea freight options give shippers a genuine alternative for less time-critical volume. As blending mandates spread beyond Europe over the next few years, having a forwarder that tracks these regulatory shifts across multiple markets — rather than reacting to one surcharge notice at a time — is going to matter more, not less, for anyone whose transportation logistics planning depends on predictable air cargo costs.
Frequently Asked Questions
SAF is produced from renewable feedstocks such as used cooking oil, animal fats, agricultural and forestry residues, municipal solid waste, and increasingly from synthetic power-to-liquid pathways that combine captured carbon dioxide with hydrogen produced using renewable electricity. It is chemically similar enough to conventional jet fuel to be blended and used in existing aircraft engines without modification.
SAF production capacity is still a small fraction of global jet fuel demand, feedstocks are limited and compete with the renewable diesel industry, and refining infrastructure built specifically for SAF requires significant capital investment. Until supply scales up substantially, SAF is likely to keep costing several times more per tonne than conventional jet fuel.
Very likely, at least on lanes touching the European Union and other jurisdictions with blending mandates. Airlines and cargo carriers generally pass the incremental cost of blended SAF through to customers via a fuel or SAF-related surcharge layered on top of the base air waybill rate, rather than absorbing it into their margins.
For cargo that isn't genuinely time-critical, shifting volume to ocean freight, or to a hybrid sea-air routing, is a reasonable way to manage rising air cargo costs. For shipments where speed is the whole point, the better lever is usually consolidating volume with a forwarder who can compare surcharge structures across multiple carriers rather than abandoning air freight altogether.
