About: http://webisa.webdatacommons.org/354038119

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	However, polytetrafluoroethylene (PTFE) that does not contain impurities such as boron (B) or metal and is not corroded by acid, alkali, organic solvent or the like can be used as the filtering material.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com