Chemistry enables more than 95% of products in the marketplace. Over the past 20 years, various entities began to generate inventories of chemicals (“chemical watch lists”) potentially associated with human or environmental health risks. Some lists included thousands of chemicals, while others listed only a few chemistries with limited properties or toxicological endpoints (e.g., neurotoxicants). Enacted on October 1, 2013, the California Safer Consumer Products Regulation (SCP) utilized data from chemical inventory lists to create one master list. This paper aims to discuss the background and requirements of this regulation. Additionally, we wanted to understand the universe of Candidate Chemicals identified by the Regulation. Data from all 23 chemical lists identified in the SCP Regulation were entered into a database. The most prevalent chemicals among the ∼2900 chemicals are identified, including the most prevalent chemical, lead, appearing on 65% of lists, followed by DEHP (52%), perchloroethylene (48%), and benzene (48%). Our results indicated that the most prevalent Candidate Chemicals were either persistent, bioaccumulative, carcinogenic, or reprotoxic. This regulation will have wide-ranging impact in California and throughout the global supply chain, which is highlighted through selected examples and case studies.