From Bern's owners manual
HARD HAT WARNING
Use this hard hat at your own risk! This product does NOT meet ASTM or EN standards for protective head gear for use in non motorized situations. It is a HARD HAT. Bern's helmets use hard foam hat is designed to break apart to absorb higher impacts. Bern's HARD HATS use soft foam lining to provide added protection from multiple lower force impacts.
EPS helmets comply with the EN1077, EN1078, CPSC and ASTM F 2040 Standard Specifications for helmets.
Also I talked to a Bern athlete about what to buy, and he said DON'T GET A HARD HAT. It's a hard hat, not a helmet.
DON'T GET A HARD HAT!