Thesis (MBA)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The process safety culture maturity of Sasol Infrachem; namely, Infragas, the Water and Waste, Ammonia and Steam Stations plants, are assessed using human factors dimensions related to man-machine, employee job roles and organisational culture interfaces. Numerous global process safety incidents resulting in catastrophic consequences originating from human and organisational factors have encouraged the organisation to investigate the underlying human factors concerned, and to identify and manage key risks undermining process safety maturity. The research study construct utilises internationally recognised standards to assess process safety maturity which consists of human factors perception surveys supported by employee interviews, process safety sustainability audits, incident reporting effectiveness and assessing the underlying leadership behaviours. Perception surveys and interviews are used to find similarities or differences found in sustainability progress and incident reporting. Primary leadership drivers that hinder process safety maturity related to unwillingness to accept accountability, employee blame, fear and lack of trust are associated with ineffective process safety incident reporting and lack of organisational learning. Key human factors risks identified and assessed in the study are additional resources required to update operating procedures, the provision of employee competence assurance and ineffective safety communication related to equipment labelling that has caused occurrence of repeat process safety incidents. Three process safety maturity models are used to assess the four plants based on commitment towards continuous improvement; incident reporting effectiveness and examining interdependent team leadership behaviours through process safety balance scorecard metrics. The research results indicate the process safety maturity levels in decreasing order are Infragas, Ammonia, Water and Waste and Steam Stations plants. Suggestions are made to accelerate process safety maturity with the aim of effective interchange of knowledge, experience and behaviours related to man-machine, employee job roles, organisational culture and leadership dimensions.