There are three main bodies that test helmets for safety: the American Society of Testing Materials, International (ASTM), the European Committee for Standardization (CE EN), and the CPSC (Consumer Product Safety Commission).
ASTM F2040 - Non-Motorized Snow Sports
Requires that these helmets pass positional stability (roll off) and strength retention tests.
EN 1077A/B - Ski and Snowboard Helmets
Helmets are tested for blunt impact protection, sharp and pointed object penetration, chin strap resistance, area of coverage, field of vision and clearance between the head and shell.
EN 1078 - Bicycle and Skateboard Helmets
Helmets are tested for field of vision, shock absorption, and retention.
CPSC 1203 - Bike Helmets
Peripheral VisionTest, Positional Stability Test, Retention Strength Test, Impact Attenuation Test
ASTM F192 - Downhill MTB Helmets
Focuses on greater impact protection and provides performance criteria for chin bars on full-face helmets.
EN 12492 - Mountaineering Helmets
Impact Protection Standard for rock fall.