AbstractImplementing the 2009 US Tobacco Control Act established a new infrastructure for tobacco and nicotine science. At its heart is the Food and Drug Administration (FDA) Center for Tobacco Products (CTP). A key challenge facing FDA CTP is determining whether nicotine products are “appropriate to the protection of the public health,” and this is the central component of the Premarket Tobacco Application (PMTA) and Modified Risk Tobacco Application (MRTP) processes. CTP has granted such marketing orders for only a few products but has been consistent in its reasoning: the applicant demonstrated that the product(s) has low levels of Harmful and Potentially Harmful Constituents (HPHCs). By doing so, FDA has equated low levels of HPHCs with public health benefit. Other factors will be increasingly important, but the regulatory history indicates that no product will be granted a marketing order unless it has low levels of HPHCs. This science‐driven regulatory approach has been possible due to the rapid evolution of the knowledge base and expansion of scientific human resources, including establishment of a robust CTP Office of Science to evaluate the extensive dossiers that manufacturers must submit. Companies therefore established internal regulatory science programs, and contract research organizations developed capabilities needed to support regulatory dossiers. This article focuses on the chemistry and toxicology part of the regulatory science process and also presents the industry side of the regulatory process by examining the experience of one company—Swedish Match—that was granted the first PMTA and MRTP marketing authorizations.