WASHINGTON (BRAIN) — The Consumer Product Safety Commission issued a warning to stop using Camzimo bike helmets sold on Amazon.com because they can fail to protect during a crash.The CPSC issued a Notice of Violation to seller Shanxixijuanguojimaoyiyouxiangongsi of China, which has not agreed to issue a recall or offer a remedy. The CPSC said the helmets do not comply with the impact attenuation, dynamic strength of retention system, positional stability, or certification and labeling requirements of the mandatory federal safety standard for bike helmets.