Somewhere in most fuel offers there is a line that reads something like “HEFA, ISCC CORSIA certified, mass balance”. Four or five capitalised terms, no punctuation between them doing any real work, and a buyer left to work out which one is the important one.
It is the wrong question. They are not comparable, and that is the whole difficulty: each one answers something different, and they happen to share a line.
Why do these names get mixed up?
Because nothing on the page tells you what kind of thing each one is.
Sort them by the question they answer and the confusion mostly dissolves:
| Term | What kind of thing it is | The question it answers |
|---|---|---|
| HEFA | A production pathway | How was this fuel made? |
| ISCC, RSB | A certification scheme | Who checked it? |
| ISCC EU, ISCC CORSIA, ISCC PLUS | A rulebook within that scheme | Checked against which rules? |
| CORSIA, RED III | A regulatory framework | Whose criteria was it checked against? |
| Mass balance | A chain of custody option | How was it tracked through the supply chain? |
Read that way, “HEFA, ISCC CORSIA certified, mass balance” is not a list of competing credentials. It is one fuel described from four angles.
What is HEFA?
Hydroprocessed Esters and Fatty Acids, and it is the route by which most sustainable aviation fuel is made today. It converts used cooking oil, animal fats, tallow and technical corn oil into jet fuel.
HEFA is chemistry and plant engineering. It is not a certification, it offers no sustainability assurance of its own, and a fuel being HEFA tells you nothing about whether anyone independent has examined the feedstock behind it. Two HEFA batches can have entirely different sustainability profiles depending on what went into them and where it came from.
This is the single most common mix-up we meet in proposals. HEFA sits in the “how it was made” column, never in the “who checked it” one.
What is the difference between ISCC EU, ISCC CORSIA and ISCC PLUS?
One certification body, three rulebooks, and the right one depends on the claim being made.
ISCC EU certifies against the EU’s Renewable Energy Directive, and our current certificate is issued under RED III. ISCC CORSIA certifies against the criteria ICAO set for international aviation. ISCC PLUS is the scheme ISCC runs for the markets those two do not reach; unlike the other two, its certificate names no regulation, and ours records a mass balance chain of custody.
Future Energy Global holds all three, so whichever rulebook a batch was certified under, its attributes reach you with the certificate intact. What we sell is for voluntary claims. A CORSIA certification describes the fuel. It does not make a purchase from us count towards an airline’s CORSIA requirement.
Does RSB work the same way?
Yes, and seeing it twice is what makes the pattern click.
Our single RSB certificate names four rulebooks: RSB Global, RSB EU RED, RSB ICAO CORSIA, and RSB Book and Claim. Same structure as ISCC. One body, several standards, selected by the market and the mechanism rather than by preference.
So the useful question is never “are you RSB or ISCC”. It is “which standard was this batch certified under, and does that standard answer the claim I need to make”.
Which acronym belongs in my claim?
The rulebook, and the certificate number that proves it.
A claim that says “HEFA fuel” describes a manufacturing process and commits to nothing. A claim that says “certified under ISCC CORSIA, certificate number ISCC-CORSIA-Cert-US201-209512025, retired to us and to no one else” is a statement someone can go and verify. The first is a specification. The second survives an audit.
When an offer arrives with a row of acronyms, the questions worth asking are short. Which standard, which certificate number, which chain of custody, and has the reduction been retired to anyone already. A supplier who can answer all four quickly is a supplier with the documentation behind them.