16 C.F.R. § 1203.5 Construction requirements—projections.
Title 16 - Commercial Practices
Any unfaired projection extending more than 7 mm (0.28 in.) from the helmet's outer surface shall break away or collapse when impacted with forces equivalent to those produced by the applicable impact-attenuation tests in §1203.17 of this standard. There shall be no fixture on the helmet's inner surface projecting more than 2 mm into the helmet interior.
Title 16: Commercial Practices
PART 1203—SAFETY STANDARD FOR BICYCLE HELMETS
Subpart A—The Standard
§ 1203.5 Construction requirements—projections.
