Which materials are “critical” and which are “strategic”?

By IM Staff
Published: Monday, 30 November 2015

The terms “critical” and “strategic” used to describe the importance of various minerals and metals to different countries and organisations are often applied without definition or context. George J Simandl, Carlee Akam and Suzanne Paradis outline the case for appropriate use of these terms to avoid misunderstandings and misrepresentations.

Raw materials are essential to the global economy and for maintaining and improving our quality of life. Recent years have witnessed rapid growth in the use and demand for metals or industrial minerals used in high-tech products. Availability of these materials at competitive prices is essential for advances in high-tech products, clean energy technology and commercialising new inventions. 

crtical1Most demand and supply analyses emphasise technical, economic, environmental and social parameters and technologic breakthroughs. "Criticality analysis" does the same, but focuses on identifying and evaluating the risks and impacts of supply disruptions on the economy, national security, implementing green energy programmes, or other initiatives, depending on the interests of the organisation that commissions the study. Metals that are commonly perceived as "critical" or "strategic" are rare earth elements (REE), tantalum (Ta), niobium (Nb), lithium (Li), beryllium (Be), gallium (Ga), germanium (Ge), indium (In), zirconia and graphite. 

For many materials (e.g., limestone, silica sand and iron), reserves, resources and producing mines are abundant and widely distributed. For these materials, future supply is not at risk and can be crudely assessed by using the ratios of global reserve/yearly production and global resource/yearly production. For other materials (e.g., heavy rare earth elements (HREE), Nb, antimony (Sb)), the assessment is more complex. Factors such as authoritarian regimes, monopoly- or oligopoly-type market conditions, political instability and potential or existing regional conflicts can threaten reliable supply and analyses must account for these risks. Furthermore, some high-tech metals are derived as by-products of base metal extraction (e.g., Ga, Ge and In). Their level of production cannot be easily increased independently of the main base metal co-products, without a major increase in their price. 

According to the Webster’s New Collegiate Dictionary (1975), the distinction between "critical" ("indispensable for the weathering, solution, or overcoming of a crisis") and "strategic" ("required for the conduct of war materials, or necessary to, or important in, the initiation, conduct, or completion of strategic plan") may be seen as subtle or non-existent. These definitions are more or less in line with current European use (e.g., European Commission (EC), 2011 and 2014a), where "critical" materials are considered to be of high economic or trade importance, whereas "strategic" materials are those essential to a country’s defence. In North America, Ishee et al. (2013), define a mineral as "critical" if it is essential to a vital sector of the US economy and as "strategic" if it is "important to the nation’s economy, particularly for defence issues; does not have many replacements; and primarily comes from foreign countries". However, the same publication acknowledges that US government-wide definitions do not exist. Similar to government publications, the distinction between the terms "critical" and "strategic" is largely lost in scientific and technical publications, trade journals and newspapers.

This article summarises lists of critical and strategic materials prepared by the EC, the US Department of Defense (DoD) and the US Department of Energy (DoE), emphasising that lists of critical and strategic materials differ, based on whether the criticality
analyses is being applied to the general economy (EC), the military (DoD), or clean-air technologies (DoE) and that these lists change through time due to technological breakthroughs, political pressures and instabilities, and depletion of resources. It underlines that the designation of a material as "critical" or "strategic" depends on the subject and focus of study; therefore, if the terms "critical" and "strategic" are used, they should be clearly defined in an early portion of the publication and should not be applied out of context.   


Case studies 

Critical raw materials from the economic point of view: the EC

With a long mining history, most major near-surface deposits in Europe have been mined out. Some deposits in densely populated areas are undeveloped due to strict environmental regulations. Therefore, discovery, permitting and development of new mines in Central and Western Europe appear more difficult relative to other parts of the world. Securing reliable access to raw materials at competitive prices is an ongoing concern for most industrialised European countries, such as the UK and Germany, and is reflected in several studies (e.g., Erdman et al., 2011; British Geological Survey, 2012; EC 2011, 2014a,b).

The EC released its first report on critical raw materials for the EU in 2011, updating it in 2014 (EC, 2011, 2014a, b), with plans to produce revised versions every three years. The methodology used in both studies is identical. Economic importance was determined by assessing the proportion of each material associated with industrial mega-sectors at an EU level. These proportions were then combined with the mega-sectors’ gross value added to the EU’s GDP. The total was then scaled according to the total EU GDP to define an overall economic importance for the material. To quantify the supply risk, the EC relied on the World Governance Indicator (WGI). The WGI includes factors such as voice and accountability, political stability and absence of violence, government effectiveness, regulatory quality, rule of law and control of corruption (EC, 2014a). Both iterations identified critical metals in terms of two key factors: 1) importance to the economy of the EU; and 2) an estimate of the level of risk associated with supply of each material under consideration. 

The 2011 study identified 14 materials as critical from a starting list of 41 non-energy, non-food materials. This list included cobalt (Co), fluorspar, graphite, magnesium (Mg), platinum group elements (PGE), REE (yttrium (Y), scandium (Sc), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium, ytterbium (Yb) and lutetium (Lu)), tungsten (W), Ta, Sb, Be, Ga, Ge, In and Nb (EC, 2011).

The 2014 study started with a list of 54 materials and identified 19 as critical (Figure 1). The extended list included seven new abiotic materials and four biotic materials, including coking coal. For the purpose of this article, biotic materials are omitted. In addition to this expansion, the REE were subdivided into "heavy" and "light" categories (EC, 2014a). The current list of critical inorganic materials specific to the European community includes: borates, chromium (Cr), fluorspar, magnesite, natural graphite, phosphate rock, heavy REE, light REE, silicon metal, Sb, Be, Co, Ga, Ge, In, Mg, Nb, PGE and W (EC, 2014a). Ta and Sc were downgraded to non-critical in the 2014 study. 


Critical and strategic materials from the military point of view: US DoD

A study commissioned by the US DoD considered the stockpile requirements and availability of 76 materials (US DoD, 2013). It identified 23 materials that would exhibit "shortfalls" during a hypothetical four-year time interval, consisting of one year of all out conflict involving the US followed by three years of recovery (starting in 2015 and lasting until the end of 2018). Referred to as "critical and strategic", the materials determined to be in shortfall are tin (Sn), aluminum oxide fused (Al2O3), bismuth (Bi), manganese (Mn), silicon carbide (SiC), fluorspar (acid grade), Sb, W, Ta, Ge, Be, Cr, Dy, Er, Ga, Tb, Tm, Y, Sc and four proprietary materials, including three types of carbon fibres and a rare earth oxide (Figure 2). 

Critical materials from the clean energy point of view: US DoE

A report prepared by the US DoE Office of Policy and International Affairs (US DoE, 2011) highlighted the importance of 16 elements needed to develop clean technologies, such as wind turbines, electric vehicles, photovoltaic thin films and energy-efficient lighting, and light REE (especially La and Ce) as catalysts to produce gasoline. The criticality of these materials was assessed for the periods 2011 to 2015 and 2015 to 2025. Both assessments were based on: 1) the importance to clean energy; and 2) the level of supply risk. In the assessment for 2015 to 2025 (Figure 3), Nd, Dy, Eu, Y and Tb were considered critical, Li and tellurium (Te) were considered near-critical and Ce, La, Sm, Pr, Mn, Co, In, Ga, and nickel as non-critical. In the earlier assessment period, Li was judged as non-critical, whereas Ce, La, Te and In were classified as near-critical. Dy, Eu, Nd, Tb and Y remained on the critical list during both assessment periods. 



Table 1 summarises the results of four criticality studies released since 2011. The document released by the EC in 2011 lists all REEs, plus 13 other materials. The EC’s 2014 report identified five industrial minerals, REE (excluding Sc), PGE and 10 other metals and coking coal as critical. The list of strategic and critical materials prepared for the US DoD (2013) reported 23 materials as strategic and critical, including SiC, fused Al2O3, fluorspar, seven REEs (one of which is not shown in Table 1), 10 metals, and three types of carbon fibre (also omitted from Table 1). The report of the US DoE (2011) found five REEs (Nd, Dy, Eu, Y and Tb) to be critical and two metals (Li and Te) to be near-critical for the period of 2015 to 2025 (Figure 3 and Table 1). Thirteen materials are common to at least three of the studies but only three elements (Dy, Tb, and Y) are common to all four studies. 


The lack of consistency in use of the terms "critical" and "strategic" leads to misunderstandings, miscommunications and potentially misrepresentations. Which materials are considered critical depends to a large extent on the priorities and objectives of the organisation or country that commissions the study. Therefore, if the terms "critical" and "strategic" are used, they should be clearly defined and should not be applied out of context.  The lists of critical and strategic materials produced by the EC (2011 and 2014), the US DoD (2013) and the US DoE (2011) differ significantly and illustrate this point. The longest list of critical materials comes from the EC (2014), which considered risks to overall economy and was broad in focus. The shortest list comes from the highly focused study of the US DoE, which considered only the supply risks for materials essential to develop clean air technologies. Lists of critical materials change with time because of breakthroughs in technology, political instabilities in major producing countries, environmental pressures and discovery, development, or exhaustion of resources.  


Reviewed by Michaela Neetz of the British Columbia Geological Survey.  


British Geological Survey, 2012. Risk list 2012- An update to supply risk index for elements or element groups that are of economic value.

Erdman, L., Behrendt, S., and Feil, M., 2011. Kritische Rohstoffe fur Deutschland.  Final report, Commissioned by KfW Bankengruppe, Berlin, 134p.

European Commission, 2011. Critical raw materials for the EU. 

European Commission, 2014a. Report on critical raw materials for the EU, 41p. 

European Commission, 2014b. Annexes to the report on critical raw materials for the EU. 

Ishee, J., Alpern, E., and Demas, A., 2013. Going critical: being strategic with our mineral resources. US Department of the Interior, US Geological Survey. 

US Department of Defense, 2013. Strategic and critical materials 2013 report on stockpile requirements. Office of the Under Secretary of Defense for Acquisition, Technology and Logistics, 189p. 

US Department of Energy, 2011. Critical Materials Strategy. Office of Policy and International Affairs, 190p.

Webster’s New Collegiate Dictionary, 1975. Webster’s New Collegiate Dictionary. Thomas Allen & Son Ltd, Toronto, 1536p.

*George J Simandl is a specialist at the British Columbia Geological Survey, Ministry of Energy and Mines, based in Victoria, BC; Carlee Akam is a student at the School of Earth and Ocean Sciences, University of Victoria; Suzanne Paradis is a research scientist at the Geological Survey of Canada, Pacific Division, based in Sidney, BC. Corresponding author: George.Simandl@gov.bc.ca