while often confused as being similar or identical, must conform to their own respective ASTM standards. Heating oil is widely used in both the United States and Canada, with U.S. residential use most common in the northeastern states of New York and Pennsylvania and in New England, collectively accounting for 85% of total U.S. residential heating oil use. In the United States, biodiesel blends of B5 (5% biodiesel) and B20 (20% biodiesel) are available in most markets as a lower and cleaner burning heating fuel. The heating oil futures contract trades in units of with a minimum fluctuation of $0.0001 per gallon and (for the USA) is based on delivery in New York Harbor. The Department of Energy tracks the prices homeowners pay for home heating fuel (oil and propane). There are also a number of websites that allow home owners to compare the price per gallon they are paying with the Department of Energy data as well as other consumers in their area. Likewise the US Energy Information Administration collects heating oil price statistics and maintains historical price data for all major US markets during each heating season. The US Department of Energy also supports research and development for heating oil technology through the National Oilheat Research Alliance. Additional information about biodiesel heating oil use can also be found at the National Biodiesel Board's site. Heating oil is mostly used in the northeastern and northwestern urban United States and a strong market presence in rural areas as well. Most of the northeast's heating oil comes from Irving Oil's refinery in Saint John, New Brunswick, the largest oil refinery in Canada. Unlike other petroleum products, heating oil is primarily distributed to consumers through family-owned small businesses, rather than the large oil companies. Although United States distributors provide the Department of Energy the average price per gallon for their users, they typically do not list their prices on comparison websites, instead preferring to provide quotes which best match the property. Republic of Ireland and Northern Ireland Heating oil is the most common fuel for home heating in Northern Ireland due to the late development of a natural gas network. Common suppliers of heating oil in Ireland are Maxol, Patterson Oil and Emo Oil. England, Scotland and Wales In England, Scotland and Wales, there are two types of heating oil: commercial heating oil – referring to gas oil, i.e. red diesel –