This part 1420, a consumer product safety standard, prescribes requirements for all terrain vehicles. The requirements for four-wheel ATVs in Sec. 1420.3 take effect on April 30, 2012, and apply to new assembled or unassembled ATVs manufactured or imported on or after that date. The restrictions on three-wheel ATVs stated in Sec. 1420.4 take effect September 13, 2008. [73 FR 67386, Nov. 14, 2008, as amended at 77 FR 12200, Feb. 29, 2012]