Yes.
According to UL Standards 486A and 486C, wire ferrules need to
have UL approval.
FerrulesDirect is the only company in the U.S. that offers UL
approved ferrules
See UL File #E326725.
This file can be viewed by clicking on the following link:
http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/showpage.html?name=ZMVV2.E326725&ccnshorttitle=Wire+Connectors+and+Soldering+Lugs+-+Component&objid=1080000623&cfgid=1073741824&version=versionless&parent_id=1073810011&sequence=1