CPSC stands for the U.S. Consumer Product Safety Commission, and their certification means the helmet has passed government-mandated impact testing. If you're buying a helmet in the United States, CPSC certification is actually required by law on all bicycle helmets sold—so any legitimate helmet you find at a reputable retailer should already have it.
Think of CPSC as the baseline safety floor. It ensures the helmet can absorb a minimum level of impact energy and protect your head in a typical crash scenario. The testing covers things like impact attenuation, strap strength, and coverage area. If a helmet doesn't carry CPSC certification, that's a red flag—especially when buying from unknown online sellers.
While CPSC is essential, it's not the whole story. Some helmets go beyond this baseline with voluntary certifications like Snell B-95, which involves more rigorous testing. And if you ride downhill mountain bikes or a speed pedelec e-bike, you'll want additional certifications (ASTM F1952 or NTA 8776) designed for higher-impact scenarios. But for road, commuting, and recreational riding, CPSC gives you the foundational protection you need.