We use cookies to ensure that our site works correctly and provides you with the best experience. If you continue using our site without changing your browser settings, we'll assume that you agree to our use of cookies. Find out more about the cookies we use and how to manage them by reading our cookies policy. Hide

Current Issue

19th February 2020
Selected Chemistry & Industry magazine issue

Select an Issue


C&I e-books

C&I e-books

C&I apps

iOS App
Android App

Endangered elements

Posted 19/03/2014 by sevans

What have Great apes, Orang-utans and the Giant Panda got in common with the elements indium, gallium, germanium and arsenic? The answer, of course, is that they are all endangered species. But while the problem of endangered animals has aroused huge amounts of public sympathy and concern, not to mention efforts to conserve and protect the affected species, the issue of endangered elements is virtually unknown among non-scientists. Now a new campaign launched this week at the American Chemical Society (ACS) meeting in Dallas, Texas, US, aims to raise awareness of the problem with the creation a novel colour coded version of the Periodic Table of the Endangered Elements.

Created by the ACS’ Green Chemistry Institute (GCI), elements highlighted in red are those whose availability poses a ‘serious threat in the next 100 years’, explained GCI’s David Constable, while those in orange, including platinum, rubidium and iridium, are under ‘rising threat from increased use’, and yet others in blue, such as selenium, phosphorus and cadmium, are ‘limited availability, future risk to supply’.

The biggest consumer of many of these threatened elements is the modern car, noted Karl Gschneidner of Ames Laboratory, Iowa State University, US, which not only contains Nd, Pd, Dy, Y, Eu, Tb and other rare species, but also requires yet more rare elements - such as Ce used to polish car windscreens – for its manufacture. Recycling of these elements from consumer products is not always practical as they are present in such tiny quantities, Gschneidner said; the energy needed for their separation is often higher than the energy required to mine and extract them from their underground ores. Instead what is needed, according to Constable, is to move the global economy towards ‘closed loop manufacturing technologies’ where process feedstocks are recycled and products reused. 

Yet another strategy involves using nanotechnology to replace these rare elements with other more plentiful ones, said Jillian Burriak of Alberta State University, Canada, referring, for example, to recent work to replace the indium tin oxide used in flat screen displays and other electronic devices with metal nanowires derived from so-called ‘rock elements’, such as iron pyrite and oxides and zinc phosphide. Using elements at the nanoscale not only means using them in incredibly tiny quantities, Burriak noted, but also confers on them new and unusual properties that can make them valuable substitutes for rarer species.

The topic of element supply, meanwhile, is particularly relevant to the theme of this the 247th ACS meeting, which focuses on ‘Chemistry and Materials for Energy’, Burriak said. With world energy demand expected to double or even triple in the next few decades, new solar technologies especially are urgently needed to fill the shortfall, with nanotechnology expected to play a major role. 

Meanwhile, if you want to support a good cause you could buy one of the GCI’s Tee-shirts like I did. It features an endangered Silverback ape on the front – with the message ‘We need our silver back!’ – and a copy of the Periodic Table of the Endangered Elements on the back. 

Cath O’Driscoll - Deputy editor

Add your comment




  • Anonymous said:
    19/03/2014 10:08

    Party balloons, squeaky voice etc etc... and yet it's a finite resource. Critical in super cooling applications.