Despite process safety and ethical decision making being recognized priorities in many chemical companies, process safety incidents continue to occur with unfortunate regularity. In order to understand why such incidents keep occurring, and to prevent future accidents from happening, it is important to study the decision-making habits of people employed at chemical companies, and to inform students of the difference between the influences of ethics and behavioral ethics in process safety decision making. This study seeks to determine how senior chemical engineering students approach reasoning through process safety scenarios through the use of a mixed methods study. This study found that four out of the five students who participated in the study demonstrated post-conventional reasoning, and the remaining student showed conventional reasoning based on the quantitative analysis of their responses. Students showed mostly post-conventional reasoning in their responses based on a qualitative analysis; however, through comparison of these results it was found that the moral schema students were classified as was not always truly representative of their moral reasoning.