As specified in FIA Technical List 25 (see www.fia.com):
FIA 8860-2010, 8860-2004
FIA standard
Snell SAH 2010, SA2010, SA2005
USA standard
Snell SA2000 (to be reclassified to Level B after 31/12/2014
USA standard
SFI 31.1/2005, 341.1/2010, 31.1A, 31.2A
USA standard
BS 6658-85 Type A/FR (not valid after 31/12/2013)
British standard