Are Hard Hats / Caps Arc Rated?

The answer is NO. There is no standard test method to arc rate a hard hat/cap.
ANSI Z89.1 2003 defines a hard cap as “a helmet without a full brim which may include a peak” and a hat as “a helmet with a full brim”. We will use the term hard hat as meaning both. ANSI
Z89.1 2009 has dropped the two definitions but both models are tested the same. ANSI Z89.1 does include a flammability test, but it does not require an FR (flame resistant) material to pass the test. The ANSI Z89.1 test method is more of an ignition test, and is less severe than the flammability test used for flame resistant fabrics.