; (B) manufacturing practices; and (C) marketing practices and postmarket reporting, with special attention to preventing consumption by youths. (4) No premarket approval required The regulation under paragraph (2) shall not require premarket approval of marijuana products described in paragraph (1). (f) No marketing in combination with certain other products A marijuana product marketed in combination with a drug, a biological product, a device, a tobacco product, or an alcohol product is deemed to be adulterated for purposes of the Federal Food, Drug, and Cosmetic Act ( 21 U.S.C. 301 et seq. ). 8. Comptroller General study on effects of marijuana legalization on traffic safety (a) In general The Comptroller General of the United States shall conduct a study on the effects of marijuana legalization on traffic safety. (b) Inclusions The study conducted under subsection (a) shall include a detailed assessment of— (1) traffic crashes, fatalities, and injuries in States that have legalized marijuana use, including whether States are able to accurately evaluate marijuana impairment in those incidents; (2) actions taken by the States referred to in paragraph (1) to address marijuana-impaired driving, including any challenges faced in addressing marijuana-impaired driving; (3) testing standards used by the States referred to in paragraph (1) to evaluate marijuana impairment in traffic crashes, fatalities, and injuries, including any scientific methods used to determine impairment and analyze data