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Fuel Standards

Technical Specification for Gas Oils, Petrol and Diesel Fuels

The Minister of Communications, Climate Action and Environment sets out the technical specifications for gas oils, petrol and diesel in Ireland.

The environmental specifications for petrol and diesel for road use and gas oil for use in non-road mobile machinery etc. are subject to regulation under S.I. 155/2011.

The regulation of sulphur content levels permitted for Heavy Fuel Oil, Gas Oil are set out in  S.I. 273/2014. This instrument also limits the sulphur content of gas oil for use in non-road mobile machinery to the same level as for petrol and diesel.

Implications for Gas Oils

Gas oil is a fuel similar to 'road' diesel, though with less stringent specifications. It is used in industry, agricultural machinery and home heating and is commonly called 'green diesel'. This is because it is marked with a green dye to distinguish it from 'road' diesel, on which full excise duty is payable. 

  • Gas oil marketed for use in non-road mobile machinery (NRMM) must contain no more than 10 milligrams of sulphur per kilogram of fuel. This is more commonly referred to as 10 ppm (parts per million) sulphur.
  • Gas oil used for home heating purposes, stationary equipment, or marine fuel continues to have an upper limit of 1,000 ppm sulphur.

Non-road mobile machinery includes tractors, agricultural equipment, construction equipment, portable generators, forklifts, forestry equipment railway engines, inland waterway vessels and recreational craft when not at sea.

Why the reduced sulphur limits?

In addition to the environmental benefits of reduced sulphur dioxide (SO2), the use of 10 ppm sulphur gas oil is also essential for the effective working of emission abatement technology in engines fitted in newer non-road mobile machinery.

Such equipment is now routinely made to meet stringent EU emission standards for oxides of nitrogen (NOx). Exposing newer enginesto high levels of sulphur, even for brief periods, will damage them.

We understand that manufacturers have stated that any such damage would not be covered under warranty.


Implications for Biofuels

Rather than separately producing 10ppm sulphur gas oil, it is understood that many suppliers will provide standard 'road' diesel specification fuel, marked green in accordance with concessionary duty requirements.

  • Road diesel is already at the 10 ppm sulphur level
  • Road diesel is in regular use and of itself should provide no performance issues to vehicles, as it is made to a more demanding standard than gas oil
  • However, the fuel specification for road diesel has been also been updated (see below) to permit suppliers to blend biofuels up to a level of 7%

In line with best practice, increased care is advised when storing 10 ppm sulphur gas oil that contains biofuel.

The following precautions should be considered:

  • Store 10 ppm sulphur gas oil separately from 1,000 ppm sulphur gas oil and should not be mixed
  • Ensure a fuel turnover period of once every 6 months and, in any event, no longer than once every 12 months. This will reduce the chance of oxidation. Oxidation can precipitate solids with the potential to block filters in fuel distribution systems or in off-road equipment fuel systems.
  • Eliminate water from fuel storage tanks. Conduct monthly checks to ensure that tanks remain free of water to reduce the possibility of bacterial growth. Such growth can result in the blockage of fuel filters and/or increased corrosion, and can also contaminate the fuel, resulting in damage to engines.
  • Replace fuel filters after the first two to three tanks (outside the regular service interval) of the new fuel to prevent those deposits from blocking filters. As biodiesel is a better solvent than current gas oil, it will pick up deposits already in fuel tanks and filters may fill up faster than usual.
  • Replace any leaking seals.

'Road' diesel is produced to a more demanding standard than gas oil. Modern off-road equipment should encounter no major difficulties as a result of using 10 ppm sulphur gas oil which contains biofuel. 

We advise the following:

  • Examine machinery fuel systems following the switch to 10 ppm sulphur gas oil and replace any seals or pipes found to be leaking'
  • For irregularly used equipment ensure the content of tanks is turned over every 6 months or in any event no less often than every 12 months to help prevent blockage of filters. 

Implications for Petrol and Diesel Fuels of Biofuel rules

The Regulations on petrol and diesel fuels include:

    • The option to increase biofuel content by blending petrol with up to 10% Ethanol (E10) and to blend diesel with up to 7% fatty acid methyl ester (FAME).
    • The requirement on suppliers of fuel to give correct information on the biofuel and FAME content of petrol and diesel respectively.
    • The requirement on suppliers of fuel to label any fuels containing metallic additives and to limit the content of these.

Exclusions from S.I. 273/2014

S.I 273 of 2014   excludes gas oil for use in

  • non-road mobile machinery, including inland waterway vessels,
  • agricultural and forestry tractors, and
  • recreational craft

    from the scope of the Regulations.

Sulphur Content of Marine Fuels

The European Union (Sulphur Content of Marine Fuels) Regulations 2015 (Statutory Instrument No. 361 of 2015) implement in Irish law certain provisions of Directive 2012/33/EU of the European Parliament and of the Council of 21 November 2012 amending Council Directive 1999/32/EC (otherwise known as the 'Sulphur Directive') as regards the sulphur content of marine fuels.

It provides, in particular,for:

  • limiting to 1.5% by mass the sulphur content in marine fuels used by passenger vessels on regular services to or from any port in the Union until 31 December 2019, and limiting it to 0.5% by mass following that date[CL2] . This should improve air quality and create sufficient demand to ensure an EU-wide supply of low sulphur fuel.
  • limiting to 0.1% by mass  the sulphur content in marine fuels used by ships at berth in order to improve air quality around ports.
  • limiting to 1.5% by mass the sulphur content of marine diesel oils sold in the European Union.
  • limiting to 0.1% by mass the sulphur content of marine gas oils sold in the European Union.