When should I replace my child's helmet?

Replace the helmet immediately after any crash where the head hits the ground, even if no damage is visible (EPS foam compresses on impact and doesn't recover). Also replace when the child has outgrown the size range, when you see cracks, dents, or frayed straps, or approximately every 3-5 years due to UV degradation and foam aging. Children grow quickly, so check fit every few months.