In Brief The process of developing and scoring a certification exam is complicated and uses a scientific and mathematic psychometric process to achieve defendable outcomes. How much of the process is well understood by either the general public, employers or even safety and health professionals? This article presents information intended to help OSH professionals understand why and how a properly developed and administered certification exam shows the mark of excellence in the field of safety and health. OSH professionals inherently understand the value of holding certification credentials such as certified safety professional (CSP), Canadian registered safety professional (CRSP) and certified industrial hygienist (CIH), but knowledge about how the certification program is established and maintained may not be as prevalent. OSH professionals might also have questions about the process, such as who determines what topics go on the exam? How are questions written and approved for inclusion on the exam? How are passing scores determined? A great deal of science and mathematics is behind the process. This article aims to answer these questions and help explain why and how a properly developed and administered certification examination shows the mark of excellence in the field of safety and health. Certification vs. Certificate Program To understand the certification process, one must first understand the difference between certification and a certificate program. Professional certification is defined by Institute for Credentialing Excellence (ICE) as a "voluntary process by which a nongovernmental entity grants a time-limited recognition and use of a credential to an individual after verifying that he or she has met predetermined and standardized criteria" (Knapp, Fabrey, Rops, et al., 2006, p. 6). It is a process based on existing legal and psychometric requirements by which individuals who have demonstrated a specific level of knowledge or skill required by a profession are identified to the public and other stakeholders (Knapp, et al., 2006). Certification programs evaluate professionals against an established industry standard set through a defensible process (often called a job task analysis or role delineation process) resulting in the establishment of appropriate benchmarks of required knowledge and skills (Wright, Turnbeaugh, Weldon, et al., 2015). Certification is awarded for a specific duration with required continuing professional development reported on a set cycle (Wright, et al., 2015). If a certificant does not fulfill the required maintenance activities, the certification award expires.