Currently, there are three (3) non-wood baseball bats that the NFHS has decertified for use in high school competition.  This short list is subject to change.  Additional non-wood baseball bats could possibly be added to this list.  The decertified bats are the following:

Marucci Cat 52 33" non-wood baseball bat  (Decertification notice date: February 21, 2012)
Reebok Vector TLS 32" non-wood baseball bat  (Decertification notice date: March 26, 2012)
Reebok Vector TLS 33" non-wood baseball bat  (Decertification notice date: March 26, 2012)

These bats should be considered non-compliant and subject to NFHS Baseball Rules 4-1-3b and 7-4-1a.