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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 now regulated by the following Regulations.

The Sulphur Content levels of Heavy Fuel Oil, Gas Oil and Marine Fuels are set out in these Regulations.

The following Regulations limit 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 a slightly lower specification. It is commonly used in industry, agricultural machinery and home heating and is often referred to as ‘green diesel’, as it is marked with a green dye to distinguish it from ‘road’ diesel on which full excise duty is payable. 

  • Since January 2011, gas oil marketed for use in non-road mobile machinery (NRMM) must contain no more than 10 milligrams of sulphur per kilogram of fuel, more commonly referred to as 10 ppm (parts per million) sulphur
  • Gas oil used for home heating purposes, stationary equipment, or marine fuel will continue to have a specification 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 arising from 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 manufactured to meet stringent EU emission standards for oxides of nitrogen (NOx). These newer engines will be damaged if exposed to high levels of sulphur, even if it is only for a brief period.

We understand that manufacturers have stated that this damage will not be covered under warranty.

Implications for Biofuels
It is expected that many fuel suppliers will supply standard ‘road’ diesel marked green in accordance with concessionary duty requirements as rather than separately producing 10ppm sulphur gas oil.

  • 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 produced 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%

Increased care is advised when storing 10ppm sulphur gas oil where this contains biofuel. In brief the following precautions are advised: 

  • 10ppm sulphur gas oil must be stored separately from 1,000ppm 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 possibility of oxidation which 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 and conduct monthly checks to ensure that tanks remain free of water to reduce the possibility of bacterial growth which can result in the blockage of fuel filters, increased corrosion and also contaminate the fuel to an extent which results 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
  • Any leaking seals should be replaced.

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

  • Examine machinery fuel systems following the switch to 10 ppm sulphur gas oil and ensure that any seals or pipes found to be leaking are replaced
  • 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 changes made by the Regulations on petrol and diesel fuels are relatively minor and 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 appropriate 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 metallic additives 

Sulphur Content of Heavy Fuel Oil and Marine Fuels
Directive 2005/33/EC forms part of a European Union strategy to reduce air pollution from ships. At the moment, ships are one of the leading sources of sulphur dioxide (SO2) emissions in the EU. The Directive encompasses all liquid fuels derived from petroleum and used by ships operating in Member States' territorial waters.

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 in order to improve air quality and create sufficient demand to ensure an EU-wide supply of low sulphur fuel
  • limiting to 0.1% by mass, from 1 January 2010, 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.

The Regulations and subsequent amended Regulations exclude 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.