Food Safety: Contamination control in a food processing environment – Having HACCP helps

by Peter J. Slade, Ph.D.


Critical to the development, implementation and maintenance of sanitation standard operating procedures (SSOPs) in a food processing environment are procedures describing prevention of direct contamination of product, pre-operational (“pre-ops”) cleaning and sanitation of contact surfaces, facilities, equipment and utensils, and the type and frequency of procedures and monitoring activities that are performed to ensure compliance. Should SSOPs not prevent direct contamination or adulteration, appropriate actions must be taken. Each official manufacturing establishment is required to evaluate the effectiveness of SSOP measures and revise if necessary to keep effective and current.

The good manufacturing practices (GMP) regulations and SSOPs are considered part of general “prerequisite” programs utilized for preparation of food in hygienic, sanitary and safe conditions. Other prerequisite programs include supplier control measures, purchase specifications, receiving, storage and shipping controls and traceability and recall programs, to name a few.

But exactly why are such programs considered prerequisite? And prerequisite to what? Actually, these programs are prerequisite to the modern-day main event in food safety circles, a process control tool that goes by the name of “HACCP” (pronounced “hass-ip”), an acronym that stands for “Hazard Analysis Critical Control Points.”

Figure 1. Risk/Consequence Matrix (CFIA, 1996)

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*Number in parentheses is optional ranking classifcation by case, 1 through 16. 1 is the worst case, 16 is the best case

Satisfactory (Sa) – No deficiencies noted which result in health risk/risk of contamination or adulteration

Nonsatisfactory – If dificiencies are noted which would result in a health risk of contamination or adulteration, they are to be assessed using the following criteria:

Monir deficiency (Mi) – Deficiencies which could result in a low health risk or a low to moderate risk of contamination or adulteration.

Major deficiency (Ma) – Deficiencies which could result in a moderate health risk or a high risk of contmaination or adulteration.

Critical deficiency (Cr) – Deficiencies (including contamination) which could result on a high health risk.

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As the name suggests, HACCP represents a systematic approach to the elucidation of potential food safety hazards and identification of points in the manufacturing process critical to their control. Unlike GMPs and SSOPs, which are measures that affect both quality and sanitary properties of foodstuffs by consideration of general sanitation and hygiene conditions of the food-processing environment, the specific focus of HACCP is product safety. Product quality and spoilage concerns may also be covered by application of an effective HACCP program, but only as a secondary benefit achieved by overall control of process parameters.

HACCP has its roots in military standards from the 1960s such as Mil-Std-882 (1969), which specifies that safety should be designed into products and that hazards associated with the product and its components should be identified, eliminated or controlled to an acceptable level.

Conventional wisdom tells us that HACCP, as we know it today, was in its infancy in the early 1970s, in a collaborative venture between the National Aeronautical and Space Administration (NASA) and the Pillsbury Company. In an effort to preclude heavy reliance on finished product testing to assure the quality, safety and wholesomeness of food products destined for consumption aboard manned space flights, these organizations developed a system to assure the safety of food products through application of controls and oversight of the manufacturing process. Thus, under the premise that quality and safety cannot be inspected into a food product, HACCP took its first steps.

Key points to remember are that a hazard is defined as “a biological, chemical, or physical agent that is reasonably likely to cause illness or injury in the absence of its control.” A critical control point is defined as “a step at which control can be applied and is essential to prevent or eliminate a food safety hazard or reduce it to an acceptable level.” Of course, there is much debate over use of terms such as “reasonably likely” and “acceptable level.” The HACCP system overcomes deficiencies presented by use of such apparent subjective qualifiers, by recourse to an expert team approach. A great deal of knowledge, experience and science-based information is brought to bear in designing the HACCP plan during the deliberations of such a cross-functional, multi-disciplinary team.

Still, there are thorny issues to be addressed throughout development of the HACCP plan. In early stages, the hazard analysis poses the question of whether or not a hazard is likely to occur and is severe enough to warrant control during manufacturing. Fortunately, examples of hazard assessment and hazard evaluation tools are given in the National Advisory Committee on Microbiological Criteria for Foods (NACMCF) document (guidelines on the application of HACCP) to help address this question (NACMCF, 1997). NACMCF is a group composed of invited (term-limited) experts from academia, industry and regulatory agencies (

Another useful tool for addressing the hazard analysis question is the risk-consequence matrix presented by the Canadian Food Inspection Agency (CFIA, 1996), Figure 1. In this case, if risk is considered synonymous with “likelihood” and consequence synonymous with “severity,” use of such a two-dimensional matrix aids the planner in assigning the relative threat posed by any particular hazard. The matrix helps to indicate, therefore, whether or not the hazard needs to be considered in the HACCP plan.

Another traditional sticking point for HACCP planners in the early stages of plan development is the identification of truly critical CCPs. Again, the NACMCF document provides illustrative guidance through use of a simple decision tree device (NACMCF, 1997), Figure 2.

Does application of HACCP help control contamination in a food-processing environment?

In a narrow sense, application of broad, non-specific measures such as GMPs and SSOPs would seem to be sufficient for control of microbial contamination in such an environment. However, in a much broader sense, application of the much more narrowly focused, highly specific control measures common to most well-designed and executed HACCP programs, can only help improve the sanitary condition of the processing environment. This, of course, benefits product quality but, most importantly, also product safety.

By definition, application of control measures in HACCP aims, with single-purpose, to target those control points that are most critical to the safe and sanitary manufacture of food products.

It doesn't really matter what type of food processing technique is employed. One thing is certain: the cleaner the environment or incoming raw material, the safer, more wholesome and sound the final product will be.

A few simple examples serve to illustrate the point. In traditional canning operations, the number of spores of Bacillus or Clostridium species going into the can before thermal processing may affect the safety and/or the stability of the canned product. This is because thermal inactivation of bacterial spores follows first order kinetics; the more spores present originally, the longer it takes to reduce the probability of survivors to levels that are not detectable in any particular unit of product. Fortunately, thermal processes applied to products in hermetically sealed containers are designed to be ultra-conservative.

The lethality of each process is designed to be far in excess of the process to inactivate even the highest levels of contaminating spores imaginable. For foods that are filled in a clean or aseptic environment, the prevention of post-process contamination is essential to assure both the safety and the stability of the product. When this doesn't happen the results can be disastrous. For example, in 1998, several dozen cases of foodborne listeriosis, some resulting in deaths of consumers, were linked to alleged post-process contamination by Listeria monocytogenes in packs of hot dogs made by Bil Mar Foods, a division of Sara Lee Corporation.

Well-designed and implemented HACCP plans have an established track record for increasing assurance of safety for many food products. Many people in the food production business are also very pleased and encouraged to find that introduction of HACCP principles usually brings about other tangible, albeit peripheral, benefits such as marked improvements in process efficiencies, increased productivity and more consistent product quality, as noted previously.

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However, some “nay sayers” are more than ready to point out that HACCP, in the past, may have failed and not lived up to expectations as the premiere food process safety control tool available. They may point to unfortunate episodes, such as those at Bil Mar Foods, as evidence to support this point of view. However, it must be remembered that HACCP by itself, or even in combination with other food safety control measures, has never been promoted as an absolute guarantee of product safety.

There is no such thing as zero risk in any human endeavor. A case for “HACCP failure” can only be made by assignation of failure to the poor design and/or execution of the HACCP plan which, in itself, is merely indicative of a fundamental failing in human reliability. It could be surmised that if technical management at Bil Mar Foods had re-evaluated their HACCP plans in light of structural modifications reportedly made to the processing facility, and if any indication of increased levels of Listeria species in the production environment had been acted on, then the most severe troubles may well have been mitigated.

Notwithstanding the above, with HACCP one thing is clear. The prodigy of the 1970s is up and running. HACCP will continue to advance as a key component of systems for control of contamination of the food-processing environment. When effectively implemented, HACCP will assure the safety of the global food supply.

Peter J. Slade, Ph.D., is assistant professor of food safety/HACCP at the National Center for Food Safety and Technology/Illinois Institute of Technology-Moffett campus in Summit-Argo, IL, where he works with FDA colleagues and industry members to “assure the safety of the nation's food supply.”

HACCP application steps and principles

Guidelines for application of HACCP have been developed by the National Advisory Committee on Microbiological Criteria for Foods (NACMCF, 1997). These guidelines list five preliminary steps and seven principles of HACCP that should be followed for best effect.
The five preliminary steps are as follows:

•Assemble the HACCP team
•Describe the food and its distribution
•Identify the intended use of the food and likely consumers
•Develop a process flow diagram
•Verify the process flow diagram

The seven principles of HACCP are:
1. Conduct a hazard analysis
2. Determine the critical control points (CCPs)
3. Establish critical limits
4. Establish monitoring procedures
5. Establish corrective actions
6. Establish verification procedures
7. Establish record-keeping and documentation procedures

GMP regulations

Good Manufacturing Practices (GMPs) are a regulatory requirement in the U.S. defined by the FDA (CFR 21 Part 110) and, for meat and poultry products, by the USDA (CFR 9 Parts 308/381.45). Essentially, the GMP regulations describe universal steps or procedures that control the operational conditions within a food establishment allowing for environmental conditions that are favorable to the production of safe food. These include:

•General provisions (relating to workers)
•Disease control
•Education and training

•Buildings and facilities
•Plants and grounds
– Grounds maintenance
– Plant construction and design
•Sanitary operations
– General maintenance
– Cleaning and sanitation compounds
– Pest control
– Sanitation of food contact surfaces
– Storage and handling of cleaned portable equipment and utensils
•Sanitary facilities and controls
– Water supply
– Plumbing
– Sewage disposal
– Toilet facilities
– Hand-washing facilities
– Rubbish disposal

•Equipment and utensils
•Production/process controls
•Processes and controls
– Raw materials and other controls
– Manufacturing operations

For meat and poultry operations, the USDA has a regulatory requirement for sanitation standard operating procedures, or SSOPs (9 CFR part 416), as part of the so-called “Mega-Reg.” These regulations specify:
•Development of SSOPs
•Implementation of SSOPs
•Maintenance of SSOPs
•Corrective actions
•Record-keeping requirements
•Potential verification activities


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