The British Geological Survey (BGS) compiled a risk list that outlined the relative risk of certain elements and element groups in 2011. It ranked them according to a risk index, outlined in the following infographic, ranging from one (very low risk) to ten (very high risk). The highest ranking awarded was an 8.5, and tungsten was one of only four elements to receive it. Based on this list, tungsten is a metal facing high supply risks. Not only does Britain realize the economic importance of tungsten, but also, in the EU, it is one of 14 minerals and metals classified as critical, meaning it has significant economic importance to the member nations. The BGS describes tungsten as a key hard metal used in almost all cutting tools. It is an important metal with no substitutes, and a key component in steel manufacturing, construction, oil drilling, and mining industries. Tungsten is also used in the fabrication of wires and filaments used in electrical, heating, and lighting applications. Tungsten's ranking on the risk list is the result of an assessment of the metal using four equally-weighted criteria, which are discussed below. Scarcity The BGS used crustal abundance to determine tungsten's scarcity. Based on a 2003 report, tungsten is classified as low risk based on a crustal abundance of one parts per million. Production concentration According to the BGS, if an element's production is mainly concentrated in just a few countries, supply risk may be increased. For this criterion, the BGS World Mineral Production (2005 to 2009) report was used to determine the top three producing countries. When their combined contribution accounted for more than 75 percent of global production, an element was ranked as high risk.