Zinc (recycled)
Sourcemap impact factor: 0.79
References:
1. ICE v1.6 (2008) finds emissions to be 0.48 kg
http://www.organicexplorer.co.nz/site/organicexplore/files/ICE%20Version%201.6a.pdf
2. Okala (2007) finds emissions to be 1.1 kg
https://wiki.brown.edu/confluence/download/attachments/1443180/Impact+Factors+2007.pdf?version=1