1. The short answer
Bio-blended heating oil mixes fossil fuel with biodiesel (FAME) or hydrotreated vegetable oil (HVO) to cut the fossil share, and the rules differ sharply by country: France requires new residential boilers to run only on Biofioul F30 (up to 30 percent biocomponent) since 1 July 2022, while New York State's Bioheat law reaches a 10 percent minimum blend in 2026 (law enacted 22 December 2021). Germany has no binding federal blending percentage for heating oil in force in 2026, and its planned "Biotreppe" staircase is disputed between sources, covered in detail below. No heating-oil blending mandate was found for Spain in this research.
For you, the practical question is simpler than the legal patchwork: does the fuel your dealer offers actually match what your boiler manufacturer has approved, and does the blend change how long you can safely store it.
2. How FAME and HVO actually differ
The "Fxx" code states the maximum biocomponent by volume, so F10 means up to 10 percent and F30 up to 30 percent, while HVO100 is a pure, fossil-free drop-in fuel under the EN 15940 standard rather than a blend at all. FAME (fatty acid methyl ester, commonly called biodiesel) is produced by transesterifying vegetable oil or animal fat; it is more hygroscopic than fossil heating oil, meaning it draws in more water, and it ages faster once oxygen and warmth reach it.
HVO is produced by hydrotreating vegetable oil or waste fats into a paraffinic hydrocarbon that is chemically much closer to fossil heating oil. Because of that, HVO is generally described as more storage-stable than FAME blends, an important distinction if you are also weighing our entry on heating oil shelf life. Neither fuel changes the basic sulphur-content story covered in our low-sulphur heating oil glossary entry, since desulphurisation and bio-blending are separate processes.
3. Blending rules by country, side by side
The figures below come from different legal instruments in different countries and are not comparable percentages of the same thing; they are listed side by side rather than averaged.
| Country / region | Rule | Date | Source |
|---|---|---|---|
| France | Biofioul F30 mandatory in new residential boilers, up to 30% biocomponent | in force since 1 Jul 2022, decree 2 Oct 2022 | biofioul.info |
| New York State (USA) | Bioheat minimum blend, 10% for 2026, rising to 20% in 2030 | law enacted 22 Dec 2021 | biobased-diesel.com, 23 Dec 2021 |
| Massachusetts (USA) | 2008 Advanced Biofuels mandate suspended, voluntary program instead, no binding 2026 quota | accessed 18 Sep 2026 | mass.gov |
| Germany, per gebaeudeforum.de | GModG bio-staircase described as passed: 10/15/30/60% from 2029/2030/2035/2040 | accessed 18 Sep 2026 | gebaeudeforum.de |
| Germany, per autarc.energy | Only the 10% 2029 stage called fixed, 2035/2040 stages called still to be determined | accessed 18 Sep 2026 | autarc.energy |
| Spain | No heating-oil blending mandate found | own research, 18 Sep 2026 | own research |
No federal blending percentage for heating oil was found to be legally in force in Germany as of 18 September 2026; where sources disagree on the legal status, both are shown rather than merged into one figure. None of this changes how the daily heating oil price itself is set.
4. Germany's disputed Biotreppe, and why it matters
The legal status of Germany's planned bio-staircase for oil and gas heating is genuinely disputed between two portals, and this page treats it as unresolved rather than picking a side. Gebaeudeforum.de dates the Gebäudemodernisierungsgesetz (GModG) as passed on 23 July 2026, with binding stages of 10 percent from 1 January 2029, 15 percent from 2030, 30 percent from 2035 and 60 percent from 2040 for biomethane, bio-heating oil, bio-LPG and hydrogen in new gas and oil heating systems (gebaeudeforum.de, accessed 18 September 2026). Autarc.energy, by contrast, confirms only the 10 percent 2029 stage as fixed, and describes the 2035 and 2040 stages as "still to be determined," pointing to a draft announced for spring or April 2026 (autarc.energy, accessed 18 September 2026).
An article from heizoel24.de dated 25 February 2026 reported that oil heating may stay in use with a biocomponent carrying no CO2 price, consistent with an ongoing legislative process rather than a settled law at that point. An entry in the Bundestag's text archive on the Heating Act amendment from calendar week 28/2026 exists, but its content and the exact decision status could not be verified for this page, so it is named here only as a reference, not played off against either portal's account. Because of this disagreement, nothing on this page should be read as current German law beyond what is stated here; before ordering bio-heating oil in Germany, check the current status directly at bundestag.de, bmwsb.bund.de or gmodg.bund.de. A separate proposed "Inverkehrbringer-Quote" (supplier quota) starting at 1 percent from 2028 is, per gebaeudeforum.de, only planned as a policy outline by 1 December 2026, and is announced, not decided. Anyone comparing this against a fixed-price contract for heating oil should treat any bio-staircase percentage as provisional until confirmed at the primary source.
5. What this means for your next order
Before you order bio-blended heating oil or HVO, the practical question is not which country requires what, but whether your specific boiler is approved for the specific blend on offer. Ask your dealer for the exact Fxx grade or confirm the product is HVO100, and ask whether that matches what your boiler and burner manufacturer has approved in writing, since manufacturer approval and warranty cover are two separate things from any national blending rule.
If your dealer is switching you to a new blend for the first time, consider a partial fill rather than a full tank, so you and your technician can check for any issues before committing to a larger volume. Whether buying now or waiting makes sense for your own tank level is covered separately on our buy now or wait page for the US Northeast. Run your own numbers through our calculator to see what a partial or full order actually costs at today's price.
See what a partial or full bio-blend order would cost at today's price.
Run the calculator6. Misconceptions: what a bio-blend rule does NOT mean
A national blending mandate does not automatically mean your specific boiler is approved for that blend, and "HVO" is not simply another word for biodiesel. The percentage in an "Fxx" code is a legal ceiling on FAME content, not a guarantee that your particular appliance, tank seals and warranty terms accept it; only your boiler manufacturer's own approval list settles that question.
It is also wrong to treat Germany's Biotreppe percentages as settled figures you can plan around today: as shown above, one source calls the higher stages fixed and another calls them still to be determined, so no percentage beyond the disputed 10 percent 2029 stage should be treated as current law. Whether a fixed-price contract locks in a blend as well as a price is worth confirming separately with your supplier.