HACCP-based food safety programs have been widely acclaimed, accepted and implemented as an effective means of managing food safety risks. While HACCP training is a cornerstone of managing HACCP programs, there is little information about the effectiveness of HACCP training and the durability of HACCP knowledge. Findings reveal a link between involvement level in HACCP activities and the accuracy of HACCP knowledge over time. Opportunities for peer training in HACCP, irrespective of overall experience in the food industry provide favorable circumstances for maintaining accuracy of HACCP knowledge. The optimal window for engaging employees in HACCP is directly following the completion of training for achieving the minimal depletion level of content knowledge. This study further reveals that refresher training in HACCP is necessary within three years. Furthermore, training standardization organizations likely need a formal process of monitoring and maintaining HACCP trainer and trainee qualifications to ensure uniformity in HACCP programming.