SAF: alternative aviation fuel
What is SAF?
SAF stands for 'Sustainable Aviation Fuel,' the term our industry uses to describe a better alternative to regular aviation fuel. We prefer to call it ‘alternative aviation fuel’ because SAF still produces harmful emissions and isn’t fully sustainable.
As of 2025, flights departing from Europe include an average of 2% SAF, as required by EU rules. While this is an increase, the impact of SAF remains limited. That’s why we must prioritise SAF to better harness its benefits.
The benefits of SAF*
Using SAF is better because:
- It’s made from non-fossil resources, such as used cooking oil.
- Although SAF emits the same amount of CO₂ during flight, its total CO₂ impact is at least 65% lower over the entire lifecycle (from production to burning).
- It emits less other harmful emissions like particulates and sulphur, which impact local air quality on the ground.
* We only select SAF that meets the European Union’s sustainability criteria, as defined by the ReFuelEU Aviation Regulation.
What makes SAF better?
This is because the entire lifecycle of the raw materials is considered, including how they’re produced and processed. For example, biological feedstocks like crops remove CO₂ from the atmosphere during their growth.
The SAF we use primarily comes from used cooking oil, a waste product. The carbon in this oil is associated with its first use (frying chips). During the production, distribution, transport, and burning of SAF, CO₂ is released. But the total CO₂ emissions are much lower than those from fossil fuels: at least 65% lower for the SAF that we use.
Also, reusing cooking oil doesn't add any new CO₂ to the atmosphere. With fossil fuels, carbon stored underground is released in the form of CO₂ when it’s burned.
Besides CO₂ emissions, flying also has other negative effects on the climate. For example, the white trails planes leave behind (contrails) contribute to global warming. Plus, the release of fine particles and sulphur is bad for air quality. With SAF, these effects are smaller compared to regular fuel. Here’s why.
SAF meets the same technical standards as regular fuel, making it just as safe, but it has fewer impurities. When burned, these impurities contribute to the release of fine particles and sulphur. Since SAF has much fewer impurities, also fewer fine particles and sulphur are released during flight. As a result, contrails form less likely because they develop around these particles.
What type of alternative aviation fuel does KLM use?
We only buy SAF made from raw materials that do not compete with food or animal feed production and have a minimal effect on biodiversity. For this reason, we don’t use soy and palm oil or their byproducts to produce aviation fuel.
All SAF we purchase meets the criteria issued by:
the European Union as defined in the ReFuelEU Aviation Regulation; and the Roundtable of Sustainable Biomaterials (RSB); or the International Sustainability & Carbon Certification (ISCC).
Still a small effect
To boost the use of SAF, we began adding a small percentage to the fuel system at Amsterdam Airport Schiphol in 2022: 0.5% for every departing flight. In 2023 and 2024, we increased this to an average of 1% SAF.
As of 2025, EU rules require fuel suppliers to add an average of 2% SAF to fuel deliveries at European airports. Several countries have also introduced or announced similar mandates.
That’s why we may include a SAF surcharge in the total ticket price. The price increase depends on your travel class and the distance of your flight. All surcharge revenues will be used entirely to purchase SAF.
Even though we're using more SAF, it still makes up only a small part of all our fuel. That's because SAF is limited in supply and costs 3 to 4 times more than regular fuel. This means we're only able to enjoy the benefits of SAF to a small extent.
Leverage the benefits of SAF together
It's important for KLM and other airlines to focus on SAF to develop this market further. We hope this will drive down prices and enable us to use more SAF. Our goal: 10% SAF by 2030, based on our total kerosene consumption.
That's why we collaborate with companies that fly with us for business or cargo transport. Passengers can make a small difference by adding extra SAF to their booking. Through these collective efforts, we used 10% of the global SAF production in 2023, and we’re committed to further accelerating the use and production of SAF.
Contributing to SAF
When you book a KLM flight, you can make a voluntary contribution to extra SAF. We offer 3 contribution levels based on the estimated amount of fuel needed per passenger for your flight and the price of SAF at the time of booking.
Depending on how much you contribute, you help us fund the purchase of SAF equal to all or part of this fuel. When estimating fuel, we consider factors like aircraft type, flight distance, cargo weight, number of passengers, and the travel class you’ve booked.
You’ll also see how your contribution helps reduce our estimated CO₂ impact by adding the extra SAF to a future flight. Just to be clear, your contribution won't go as extra SAF into your plane, nor will it reduce CO₂ emissions during your flight. However, it does allow us to buy a bit more SAF to add to the airport's fuel systems.
It's our responsibility to reduce the impact of flying and become less dependent on fossil fuels. The extra SAF you pay for makes a small difference towards this goal.
Average CO₂ emissions per passenger
When you buy extra SAF, we estimate the average fuel-related CO₂ emissions per passenger. We also show the estimated reduction in CO₂ impact from your voluntary contribution. These estimates are calculated using our CO₂ calculator. This calculator considers factors like aircraft type, flight route, travel class, load factor, and our set price for SAF.
Every year, the accountancy organisation KPMG audits whether our calculation methods comply with the methods described below and are in line with international guidelines. You can find the details of this audit in the KPMG audit report.
Our latest methods and audit report:
Curious about the estimated CO₂ emissions of your flight? You can see it in My Trip or when you book a flight.
What we do with your contribution to SAF
We’ll use your entire contribution for the benefit of SAF. The extra SAF is added to the fuel system at Amsterdam Airport Schiphol (or one of the other airports where we add SAF). This means the SAF you contributed to will not be used for your specific flight. That would be logistically inefficient and complicated to arrange. Depending on the product’s availability on the market, we aim to add the extra SAF within 12 months of your flight’s departure.
Because we add SAF to the airport fuel systems, other flights also depart with more SAF on board. However, since those other airlines didn't pay for the same volume of SAF, they can’t claim the CO₂ reduction. KLM is audited annually to ensure that the claimed CO₂ reduction corresponds to the SAF certificates we have received.
The mandatory SAF surcharge included in your ticket and all other SAF-related benefits we receive via our various programs are used to buy SAF. We won’t use your voluntary contribution to meet SAF blending mandates.
Want to do more?
You can do things to lower the climate impact of your trip. The best way is to choose other types of transport instead of flying for (parts of) your journey, such as travelling by train, bus, or electric car. At some destinations, this is possible through KLM because we work with Eurostar. We offer 1 ticket that covers both the flight and high-speed train. The train is a better choice than a short connecting flight.
There are also other ways to help a little. For instance, pack lighter baggage or bring your own headphones and water bottle. You can also choose to invest in one of our selected nature regeneration projects. This won't change the environmental impact of your trip, but it will help support damaged ecosystems.
Frequently asked questions
SAF is an alternative aviation fuel made from waste and residues (now mainly used cooking oil). We can blend SAF with regular fuel for jet engines. Over its entire lifecycle, SAF has at least 65% lower CO₂ impact than regular fuel.
However, SAF is still scarce and expensive. We currently add an average of 2% SAF to flights from Europe, meeting the European mandate. The impact of SAF remains limited. Your voluntary contribution to extra SAF helps us to do a bit more.
SAF can be produced from various feedstocks such as used cooking oil, municipal waste, waste gases, and agricultural residues. It can also be made from renewable electricity and by capturing CO₂ from the air. This (synthetic) form of SAF is still under development. The SAF we use mainly comes from recycled cooking oil.
Air travel has serious negative effects on the climate. At the same time, we still have a long way to go to truly lower the impact of flying. It will be years before we see the first commercial flights powered by electricity or hydrogen. For long-distance flights, we’ll be stuck relying on fuel for an even longer time.
Until then, SAF is a way to slightly reduce the impact of flying. But it’s necessary for SAF to become available on a larger scale. Also, synthetic fuels made from CO₂ from the air and green hydrogen must be further developed. This could solve the shortage of the current SAF made from used cooking oil. That’s why we’re investing in research and development of these alternative fuels.
We know our sector has a serious impact on the climate. That's why we're trying to improve our role in how our industry operates. This requires significant investments, but we also continuously work on various smaller initiatives that can make a slight difference. We must take a broad approach to be less harmful in the future, although we're not sure how far we'll get.
Examples of improvements:
- Fleet renewal
- More energy-efficient aircraft prototypes
Weight reduction and adjustments on board