COMPUTER AND MICROBIAL CONTAMINATION

The technology is therefore the computer and microbial contamination is a specific hazard

The technology is therefore the computer and microbial contamination is a specific hazard

1. Introduction

The HACCP ( Hazard Analysis Critical Control Points) system was developed in the early 1970s. The system is used to manage the safety of food products systematically by paying special attention to those steps in the process that are essential in the production of acceptably safe foods. In the recent past? many food processing companies have introduced safety management systems based on HACCP principles. Application of the principles of HACCP has become mandatory for food companies in the European Community (EC? 1993). The HACCP system is however often used qualitatively and subjectively. A quantitative approach of the HACCP system provides a better way to set proper criteria for critical process steps (indicated as CCPs)? to execute control measures? and to optimise processes according to a certain risk. The quantitative approach can be created by the implementation of quantitative risk analysis (QRA) in existing HACCP systems (Corlett and Stier? 1991; Notermans et al.? 1994b and Buchanan? 1995).

QRA is based on quantitative data and models and consists of six activities: 1) hazard identification? 2) exposure assessment? 3) dose-response assessment? 4) risk characterisation? 5) risk management? and 6) risk communication. Steps 1 to 4 are often termed risk assessment.

As shown in Table 1? hazard identification is the first activity in both QRA and HACCP. The importance of identification of hazards is mentioned in almost every reference dealing with QRA and HACCP. However? a systematic approach to the identification of hazards for food products is hardly described anywhere. Such an approach is deemed necessary to prevent pathogens relevant to products being disregarded and is especially necessary for newly developed and modified products? because new hazards may arise in these products. Only Notermans et al. (1994a) presented a general approach to the systematic identification of microbiological hazards for food products. This approach inspired the current development of a computer aided system for hazard identification. Our hazard identification procedure differs from Notermans' approach mainly by a stepwise identification of important hazards and its interactive character. Stepwise identification of relevant hazards is based on the use of three levels of detail ranging from rough hazard identification to comprehensive hazard identification. The interactive character results from systematically using several knowledge sources in identifying hazards. The knowledge sources are: literature knowledge? expert knowledge? and the user's knowledge.

Table 1. Steps in quantitative risk analysis (QRA) and in the HACCP system

2. Background

The hazard identification procedure is shown in Fig. 1. The starting point of the hazard identification procedure is a list of microorganisms that are known to be pathogenic to man. Currently the list contains about 200 names of pathogens. Then three options can be selected: 1. rough hazard identification? 2. detailed hazard identification? and 3. comprehensive hazard identification. The process of consecutively using the levels of detail is illustrated in Fig. 2.

Fig. 1. Hazard identification ...