About: http://webisa.webdatacommons.org/216237082

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	The iron, nickel, chromium, sodium, potassium, chlorine and fluorine impurities should particularly preferably each amount to less than 10 ppm, particularly preferably less than 5 ppm, and also preferably in total less than 30 ppm.
http://www.w3.org/ns/prov#wasQuotedFrom	google.fr