Introducing human, organizational and technical/technological factors in a risk assessment model represents a significant step forward in the occupational health and safety field. The best known problems of risk assessment models are their inability to cope with the uncertainties, subjectivity and static nature of the process. The improvements in the risk assessment model presented relate to these problems. Three groups of factors are introduced and their hierarchical structures are defined. The relative importance of the factors and sub-factors and values of the sub-factors are described by predefined linguistic expressions. Fuzzy set theory is used for the modeling of existing uncertainties. The risk assessment model is based on quantitative risk assessment and reducing the risk level is possible through changing the initial values of the sub-factors identified. Varying the values allows the reduction of the risk level between two regular risk assessment processes or permits planning of proactive actions and activities in order to eliminate hazards or reduce risk level in the period considered. The proposed model is tested with real data from one production company.