Due to the large quantities of hazardous materials stored and processed, chemical and process plants may be attractive targets for security attacks (e.g. terrorist attacks) that can severely impact workers, the population, the surrounding environment, and property. According to well established Security Vulnerability Assessment (SVA) and Security Risk Assessment (SRA) methodologies, the shooting threat to a chemical and process facility shall be investigated; however, the development of adequate damage models in case of shooting attacks using small/light weapons to industrial equipment units is still lacking. In the present study, an extended set of perforation models was retrieved from the literature and was validated against experimental data from perforation tests. The most reliable perforation models for soft core projectiles were selected and used to assess the vulnerability to perforation of atmospheric tanks storing hazardous materials for two reference projectiles enabling the identification of inherent safety threshold values for perforation thickness.