Nitro fuel rules: what the rule books and the law allow it to contain.

What IFMAR allows in the tank

IFMAR's IC rule books define the fuel by listing what it may contain and naming what it may not. The 1/8 IC track book (2023, rule 5.23) and the 1/8 IC off-road book (2024, rule 2.7) give the same list; the 1/10 IC track book (2024, rule 5.22.1) keeps the ingredients but lowers two limits, as does the 1/8 GT and GTE track book (2025, rule 4.2) for the IC GT class.

The nitromethane figure depends on the class, so the class and edition always need naming: 25 percent is the 1/8 limit in the 2023 and 2024 books, and 16 percent is the 1/10 track limit in the 2024 book and the 1/8 GT limit in the 2025 GT book.

Testing and controlled fuel

• IFMAR may sample fuel and penalise manufacturers (1/8 IC track 2023 and 1/8 IC off-road 2024). The off-road book provides for random fuel tests, with disqualification for prohibited additives.
• At World Championships the 1/8 IC track book (5.23) requires controlled fuel, commercially available, from up to three brands, and each supplier must send IFMAR a safety data sheet listing the full ingredients two months before the event.

EFRA, ROAR and the BRCA

EFRA's IC appendices for 1/8 track, 1/8 off-road and 1/10 track were not read for this site, so EFRA's fuel limit is not given here. A 2023 EFRA 1/8 off-road proposal to use only "16% EU" fuel at its European Championships was seen only in a search summary, and whether it was adopted was not confirmed. ROAR's current rule book and the BRCA's 2026 section rules were not read, so their fuel limits are not given either.

The law in the European Union

Separately from any racing rule, the EU restricts nitromethane as an explosives precursor under Regulation (EU) 2019/1148 of 20 June 2019 on the marketing and use of explosives precursors. The annex that sets the thresholds was not read for this site, so the limit rests on a national authority's summary:

• Estonian Ministry of Economic Affairs (page updated 28 August 2023): under Regulation (EU) 2019/1148, applicable from 1 February 2021, nitromethane above 16 percent by weight is restricted. Private individuals acting outside a trade or profession may not acquire, bring in, possess or use it, and businesses may not supply it to them.

A disagreement over the figure

The trade site RedRC, reporting on 5 October 2023 on European Parliament petition No 0519/2023 (submitted by an individual petitioner and supported by EFRA), described the change as a cut in the nitromethane permitted to model pilots and drivers from 25 percent to 12 percent under the same regulation. The petitioner argued that the change would prevent European or World Championships being held in Germany. The 12 percent figure was not found in any regulator's text. So the two versions are:

• 16 percent by weight, per Estonia's ministry;
• 12 percent, per RedRC's report.

Neither has been confirmed against the regulation's annex. The ministry's page is a government source, but it is one member state's summary, not the regulation itself.

Why the numbers do not line up

IFMAR's limits are by volume; the EU threshold given by Estonia's ministry is by weight. The two numbers cannot be compared directly, and no regulator's statement was found on whether events held in the EU may use 25 percent fuel, or on licensing under the regulation.

What regulators say about the two chemicals

Hazard information comes only from regulators, not from fuel makers. In short: NIOSH classes methanol as a Class IB flammable liquid and lists visual disturbance and optic nerve damage among its effects; it classes nitromethane as a Class IC flammable liquid. The HSE's technical report of March 2026 concludes that nitromethane meets the criteria for Acute Toxicity 4, STOT RE 2, Carcinogenicity 1B and Reproductive Toxicity 1B, in agreement with the ECHA's risk assessment committee, but says that classification had not yet been adopted in Great Britain. The two chemicals have different ratings and are never merged into one "nitro fuel" rating on this site. The full detail is on fuel hazards.

Carrying fuel

No transport regulator's page on carrying model-engine fuel by air or road was read for this site, so nothing is said here about travelling with it.