The HACCP study

As a preventative approach to ensuring consumer safety, the HACCP concept of food safety management fits with QA philosophy generally and the operation of HACCP systems should fall within the scope of a grower's QA strategy. The resources needed to develop, implement and maintain HACCP systems should be furnished as part of a grower's overall QA provision. Though the employees of a business can directly influence the safety of products through their actions, the business as a whole carries a corporate responsibility for assuring no harm comes to consumers through eating their products. The ultimate responsibility for food safety and consumer protection in any food business should rest with top management (the chief executive or someone of equivalent status) who should also be responsible for ensuring that the resources for HACCP are adequate. This is necessary even though top management may have little direct contact with the mechanics of QA and food safety management. Inadequate resources in terms of qualified personnel, physical resources and time can be one of the key problems faced by food businesses in carrying out HACCP studies and in implementing, operating and maintaining HACCP systems. Without the commitment to providing adequate resources there is little point in embarking on a HACCP study. Ensuring this commitment is a primary function of top management.

The HACCP study defines the basis for the systems of consumer protection against foodborne hazards established by food businesses, such as those operated by growers. It consists of a 12-stage process which aims to (a) analyse hazards, that is, identify the hazards most likely to be associated with a given product and the process by which it is produced, and (b) establish critical control points, that is, places in the production process where methods for the control of hazards can be applied.

6.6.1 Stage 1: Assemble the HACCP team (and define the scope and terms of reference of the study)

A HACCP team should be assembled and the scope and terms of reference of the study should be defined. The team should be multidisciplinary, containing members with the expertise required to deal with the range of issues that will arise during the study. A microbiologist (or someone with an adequate knowledge of microbiology) is usually an essential member of the team as microbial hazards must be appraised. It is also important to include members who have expertise in the crop production and pretreatment operations to be considered in the study. If the appropriate expertise is not available within an organization it may be necessary to use, for instance, the services of a consultant. The HACCP study should relate to a given crop product, its associated production process and any subsequent pretreatment processes, as relevant. The hazards arising in the production of a crop and the way they arise may be almost unique to that crop in the place where it is grown. It cannot be assumed that the factors affecting the production of a crop in one place will be identical to those affecting production of the same crop in another place. The use of generic HACCP plans is sometimes advocated as a short cut to the development of HACCP systems. Generic HACCP plans can be useful as sources of ideas and information, but the adoption of these plans can be dangerous as local factors may not be considered and hazards may be overlooked. It is better and safer to develop HACCP plans and systems locally, and avoid importing errors and misconceptions through the use of generic plans.

The scope of the study should be defined, stating the crop product to be considered by the study and identifying the production processes involved. The scope of the study sets a limit on the HACCP plan to be developed, defining where it starts and finishes. This is important, especially where complex production processes are concerned. It can be simpler (and safer) to break down processes into component operations and carry out a series of HACCP studies on 'bite-sized chunks', which link together later to form the overall HACCP system. For instance, seed preparation and propagation may form one HACCP study, with crop production, harvesting and post-harvest pretreatments forming others. When carrying out a HACCP study it can be tempting to consider the three categories of hazard - microbiological, chemical and physical - at the same time. This can lead to complications and by defining the terms of reference of the study an agreement is made to limit the study to, for example, microbial hazards, with the intention of considering chemical and physical hazards later. Knowledge gained during an initial study can be transferred to later studies, thereby reducing subsequent workloads.

6.6.2 Stage 2: Describe the product

A complete description of the product should be developed. The aim is to provide information that will enable the identification of hazards associated with intrinsic characteristics of the product itself, or from conditions concerning, for example, its packaging, storage, transport and distribution. In the manufacture of formulated foods, intrinsic preservation factors such as pH, salt-in-moisture content and water activity (aw) are important to consider as they relate to the survival and growth of bacterial pathogens. In the case of fruit and vegetables such factors may be of lesser value, though, for instance, characteristics of the product resulting from harvesting, post-harvest handling and storage, and so on, may be relevant to the presence or development of hazards and should be considered. Similarly, the packaging of a crop may be defined as a part of the final product and should be assessed for its potential to be hazardous, for example, plastic bags can represent a suffocation risk for young children, or give rise to hazards, and the use of wooden boxes and pallets should be assessed in this respect. Also of importance may be the use of specific storage conditions, such as modified atmosphere storage, which might give rise to the development of hazards, for example anaerobic bacterial pathogens.

In describing the product, reference should be made to product specifications, for example specifications agreed with customers defining the quality and food safety parameters to which the product should conform. Crop production methods may result in products carrying pesticide residues, or potentially being contaminated with bacterial pathogens, and limits for both should be set in specifications. Other factors which may be specified are, for instance, physical hazards e.g. stones or fragments of wood resulting from harvesting operations and the use of harvested product management chemicals such as sprout suppressant compounds used on potatoes.

6.6.3 Stage 3: Identify the intended use of the product

The intended use of the product should be identified. The primary purpose is to identify whether the way the product is used (by a processor or consumer) could give rise to a hazard and to identify any sensitive groups for whom the product might be intrinsically harmful. It is also important to identify whether specific market requirements need to be observed. For example, only organic products or products which have not been genetically engineered may be supplied to certain markets, and some markets require certain varieties of produce, like potatoes suitable for crisp and snack food production (though these are not necessarily food safety issues). Fruits eaten without washing before sale and which might not be washed before consumption may be harmful if contaminated by pathogenic bacteria, or by high levels of pesticides or other toxic agrochemical compounds. For example, peaches and nectarines consumed whole, without removal of the skin, may have the potential to poison consumers in the event that the surface of the product is contaminated with harmful substances. Similarly, salad crops such as lettuce may not be adequately washed by consumers and may, therefore, present the risk of food poisoning if the crops havebeencontaminated byenteropatho-genic bacteria through the use of improperlycompostedmanureorfaecallycon-taminated irrigation water. In the case of crops destined for processing, the customer should be aware of the possible presence of contaminants, probably through agreement of the product specification. The customer then should be responsible for ensuring that hazards in the form of known contaminants are controlled. For example, some manufacturersofminimallyprocessedprepared salads use chlorinated water to wash saladcropmaterialstoreducelevelsofcon-tamination by one or two log cycles, andexercisecontrolsthat preventcross-contamination (Carlin and Nguyen, 1999).

When fruit and vegetables are sold toconsumersforuseinthe preparationof meals or for direct consumption the responsibilitylieswiththeproducer,andalso retailers, to ensure that the products are freefromhazardsor thatconsumersare advised accordingly. Crop production methodsshouldensurethat,forinstance, pesticide residues do not exceed MRLs, but for additional confidence in the safety of the product, and the ability of the producerandretailerto demonstratedue diligence, it may be that some productsarewashedtoreducechemicalresidue levels, for example in the case of some apples,orangesandpotatoes.Where controls are not implemented the responsibilityforcontrolfalls toconsumerswho s hould be warned of the possible existence of a hazard so they can take the appropriate course of action. This is theprincipleseeninthe exampleoffood products which contain, or may contain, nutsandwhicharelabelledtowarncon-sumers suffering from nut allergy, who fallintothecategory of'sensitivegroups'. It is necessary to identify sensitive consumerswhomaybeharmedbycharac-teristics of the product which do not normallyrepresentahazardtomostcon-sumers. Such consumers include children, pregnant women, old people and people whose immune systems are depressed. They can be more susceptible to infection by certain pathogenic bacteria, such as E. coli O157:H7 and Listeria monocytogenes. Because babies constitute a sensitive group, fruits and vegetables produced for the manufacture of baby foods may be more tightly specified than for other purposes.

6.6.4 Stage 4: Construct a flow diagram

Describing a food product and identifying its intended use generates information that serves in the identification of hazards associated with the materials used to make the product and with characteristics of the product. Many aspects of the production process may also have the potential to give rise to hazards and it should, therefore, be analysed to ensure the identification of possible hazards.

A flow diagram of the production process (Fig. 6.1) should be prepared which identifies the inputs to, and the outputs from, the process, as well as the operating conditions and parameters required to produce the product. Inputs include seed, seed treatment agents, irrigation water, manure, fertilizers and pesticides, as well as water used in post-harvest, pretreatment operations such as hydrocooling to remove field heat and washing to remove soil and contami-

Fertiliser (P+K)

Irrigation water

Fertiliser (N)

Harvesting

Trimming

Waste

Packaging materials

Packing

Cooling

Chilled storage

Distribution

Retail sale

Fig. 6.1 Example flow diagram for the production of a field salad crop.

nants, and so on. Clearly the product itself is the principal output, but others may be product that has been rejected in grading owing to damage or deterioration, or waste botanical material (e.g. from trimming and other preparation processes, soil from washing operations, etc.), all of which, given the right circumstances, could give rise to hazards. The process itself will comprise a sequence of various operations including, for example, seed propagation, field or site preparation, fertilizer applications, planting, growing, irrigation, pesticide applications, harvesting, post-harvest handling and post-harvest pretreat-ments, like cleaning and trimming, as well as storage and transport, any of which may present certain hazards. The scope of the flow diagram should be constrained by the scope of the HACCP study. It should be logically and systematically structured, and provide sufficient detail to allow the identification of hazards associated with the process without constant reference to additional information.

6.6.5 Stage 5: Confirm the flow diagram

The flow diagram may be prepared by referring to information and data concerning the crop production process and the various operations carried out as part of the process. Sources of information may include specifications or data sheets for seed, fertilizers, pesticides and so on, procedures for site preparation and crop production, procedures for harvesting, post-harvest crop management and post-harvest processing, specifications for packaging and storage. Whatever the sources used in its preparation, the completed flow diagram should be confirmed as a true representation of the production process, not a reflection of a theoretical process which differs from the true process because changes have been made which are undocumented and, possibly, unapproved. Ideally, confirmation should be made by 'walking the process', whereby the flow diagram is compared with what actually happens, as it happens. It may not be practical, however, to observe a complete growing cycle to confirm the diagram, so reference must be made to procedures, records and the experience of personnel to confirm accuracy and veracity.

6.6.6 Stage 6: Identify and analyse all potential hazards, assess the risks and identify the preventive measures (HACCP Principle 1)

The information gathered about the product and its intended use and the information contained in the process flow diagram form the basis of the hazard analysis stage of the HACCP study, along with any other relevant information, for example literature on the foodborne hazards associated with given fruit and vegetable products. All of the potential hazards associated with inputs to the crop production process, the process itself, outputs from the process and the product should be listed. Each hazard should then be analysed in turn with regard to its nature and the risk associated with it. Risk is the combination of the severity of the adverse effects of the hazard on the health of the consumer and the likelihood of the hazard occurring. It is not an easy thing to quantify. Attention should be given to establishing the risk associated with hazards, because the results will help to focus the HACCP plan on the hazards most important for ensuring the safety of consumers.

Preventive measures should be identified for every hazard that, by its nature, demands control for reasons of consumer safety and compliance with the law. If a hazard is considered to be such a low risk that it is unlikely ever to occur, it may be justifiable to exclude it from further consideration. A preventive measure is an activity, procedure or feature of a process that either prevents the occur rence of a hazard, or eliminates it, or reducesittoanacceptablelevel. Thesources of hazards in crop production and pretreatment are diverse and cannot be comprehensively considered here. They are dependentonthenature ofthecropand specific production processes involved. Asalreadystated,they maybeintroduced with inputs to the production process, or arise as part of the process, or they may be a consequence of some aspect of an outputoftheprocess.Equally,theymay arise from the product itself, possibly owing to a condition or characteristic of the product. They may be introduced by people, or be derived from the environment, and they may occur as a consequenceofafailureinthegeneralmanage-ment of the crop production processes andassociatedprocesses. Table6.1 gives a form suitable for keeping a recordoftheevaluationofhazards.

6.6.7 Stage 7: Determine the critical control points (CCPs) (HIACCP Printiple2)

A critical control point (CCP) is 'A step at which control can be applied and is essential to prevent or eliminate a food safetyhazardorreduceittoanaccept-able level' (CCFH, 1997). Preventive measures are applied at CCPs. For every hazard identified in the hazard analysis stage(Stage6)eachstepintheprocess must be assessed to determine if the step constitutesaCCP.Experienceandjudge-ment can be used to decide whether a process step is a CCP, but reference is often made to the CCP decision tree (Fig. 6.2). Answering each of the four questions in the CCP decision tree provides an invaluable aid to the identification and clarification of CCPs. For instance, the moisture in fruit is not a hazard, as moisture represents no harm to consumers. The presence of moisture can allow mould growth and the development of mycotoxins which are potentially hazardous, for example patulin resulting from the growth of Aspergillus clavatus, sometimes found in apple juice. Selecting good quality apples, which are not bruised or damaged, for processing into fruit juice and maintaining them in the right condition under appropriate storage, is necessary to prevent mould growth and the formation of mycotoxins. Product selection (a YES response to question 2) and product storage (a NO response to question 4) each represent CCPs in this instance.

Care must be taken not to create more CCPs than are needed to ensure food safety as the complexity and costs of maintaining the HACCP system will increase unnecessarily. It can be argued that the possible hazard of excessive pesticide residues on fruit and vegetables may need control through different preventive measures concerning, for example, operator training, use of the correct pesticide, application of pesticide at the advised concentration and rate, and the maintenance and calibration of spraying equipment. Of these different areas of apparent control, application at the advised concentration and rate can be defined as a CCP. Training operators, using the correct pesticide and maintaining and calibrating spraying equipment are all activities that should be dealt with under GAP. The identification of CCPs can be recorded with details of hazards in Table 6.1.

Table 6.1 Worksheet for hazard analysisandCCP identification

Process step

Hazard

Control measures

Q1*

Q2

Q3

Q4

CCP Yes/No

Justification for being a CCP

Q1. Do preventive measure(s) exist for the identified hazard?

Modify step, process or product

Is control at this step necessary for safety? ^ YES

Q2. Does this step eliminate or reduce the likely occurrence of a hazard to an acceptable level?

Q3. Could contamination with identified hazard(s) occur in excess of acceptable level(s) or could these increase to unacceptable level(s)?

Q4. Will a subsequent step eliminate identified hazard(s) or reduce the likely occurrence to an acceptable level? ^ NO

CRITICAL CONTROL POINT

'Proceed to next step in the described process

Fig. 6.2 CCP decision tree. Note that for each hazard identified, each question should be answered in relation to each step of the production process. Source: FLAIR, undated. HACCP User Guide, Concerted Action no 7, Food Linked Agro Industrial Research, 191, Rue de Vaugirard - 75015, Paris.

6.6.8 Stage 8: Establish critical limits for each CCP (HACCP Principle 3)

A critical limit is 'A criterion which separates acceptability from unacceptability' (CCFH, 1997). Critical limits establish parameters for the operation of preventive measures at CCPs and often concern quantitative values such as time, temperature, pH, aw, concentration, application rates and so on. Critical limits may be set by regulations (e.g. pesticide MRLs defined by law), they may be recommended by industry codes of practice, or, for example, be established by manufacturers of proprietary agents and growers or customers, by reference to scientifically accepted values. Provided the critical limits established for a CCP are being adhered to, product safety with respect to the CCP should be assured. In some instances operational limits for some elements of crop production processes may be set with reduced tolerances compared to the critical limits of CCPs to provide a safety margin for the management of CCPs. Records of the control activities at CCPs should be maintained for HACCP system verification and maintenance, as well as to provide evidence of due diligence in the production of safe food.

6.6.9 Stage 9: Establish a monitoring system for each CCP (HACCP Principle 4)

Monitoring activities are carried out to confirm that the controls exercised at CCPs remain effective to ensure food safety. CCPs are monitored and the monitoring activities or procedures must be capable of detecting that control has been lost. Monitoring generally consists of a planned sequence of observations or measurements and the results of monitoring are essential to show that the HACCP system is operating effectively. Monitoring methods should be as simple as possible and may concern various forms of measurement, such as temperature, time, concentrations, pH and so on, or they may be based on the observation of procedures and the checking of records. The HACCP plan should identify how each CCP is to be monitored, the frequency of monitoring and who is responsible for ensuring that monitoring is carried out. Records of monitoring activities should be maintained for HACCP system verification and maintenance, as well as for due diligence purposes. Although conventionally, monitoring activities show that control has been lost at CCPs, it can be beneficial to use monitoring, when possible, to indicate that a CCP is going out of control. Rather than allow control to be lost and then have to take corrective action to remedy the problem, it makes sense to adopt a preventive position to ensure control is maintained, as far as possible, at all times.

6.6.10 Stage 10: Establish corrective action procedures (HACCP Principle 5)

In the event that monitoring shows that a CCP is no longer in control, corrective action must be taken, (a) to return the CCP to a state of control and (b) to identify and manage any potentially non-conforming (unsafe) product. A corrective action procedure should be established for each CCP identifying a specific course of action for the return of control. It should also define requirements for identifying, segregating and testing implicated product, as appropriate, to prevent non-conforming product being inadvertently despatched to customers. Each corrective action procedure should identify the personnel responsible for taking action and controlling product, as well as the personnel responsible for verifying that control has been returned. The corrective action procedures constitute the corrective action plan for the HACCP system.

6.6.11 Stage 11: Establish verificationprocedures(HACCP Principle6)

When the HACCPplan is complete it canbeimplemented(see section6.7,below) as the HACCP system, and both validation and verification activities should be carried out. Put simply (ILSI, 1999), validation concerns answering the question: Will the system work when we put it into practice? whereas, verification should answer the question: Are we doing what we planned to do? Validation is defined (CCFH, 1997) as 'Obtaining evidence that the HACCP plan is [likely to be] effective'. Validation amounts to an assessment of the scientific and technical content of the HACCP plan. Verification is defined as (CCFH, 1997) 'The application of methods, procedures, tests and other evaluations, in addition to monitoring, to determine compliance with the HACCP plan'. In effect, verification is a check that what the HACCP plan says will be done is, in fact, done. As validation concerns checking that the elements of the HACCP plan are complete, that decisions and assumptions made during the HACCP study are sound, and that the plan is adequate to create a workable and effective food safety management system, it must be carried out before HACCP system implementation and verification. ILSI (1999) recommends a series of validation activities intended to collect objective evidence which confirms the adequacy of the plan in relation to the seven principles of HACCP:

Principle 1 (Hazard analysis): Confirm that the skills of the HACCP team members were correct for the task, that the flow diagram was suitable for the purposes of the study and that all significant hazards and appropriate preventive measures have been identified.

Principle 2 (Identify CCPs): Confirm that CCPs suitable to effect control have been identified for all significant hazards and that the CCPs are at appropriate stages of the process.

Principle 3 (Critical limits): Confirm that adequate critical limits have been identified for each hazard in relation to relevant CCPs.

Principle 4 (Monitoring): Confirm that monitoring methods and systems are capable of demonstrating the effectiveness of control measures at CCPs, and that procedures exist for the calibration of monitoring methods and systems, as appropriate.

Principle 5 (Corrective action): Confirm that corrective action procedures exist for each hazard and the relevant CCPs are sufficient to return the CCPs to control and to prevent non-conforming product from reaching customers. Also, confirm that responsibility for taking corrective action and the authority for verifying corrective action and approving the disposition of non-conforming product have been identified.

Principle 6 (Verification): Confirm that procedures and a plan for the verification of the HACCP system have been established.

Principle 7 (Documentation): Confirm that documentation describing the entire

HACCP system exists and that records required to support the system have been established.

Fundamentally, validation should seek toconfirmthattheHACCP planiscom-prehensive and will be effective as a means of protecting consumers, through the control of identified foodborne hazards, when implemented as the HACCP system. Auditing techniques, such as thoseemployedinquality systemsaudit-ing, should be used for validation.

Verification activities should confirm that the HACCP system has been implemented in compliance with the HACCP plan, and procedures (and any other methods or tests deemed necessary) shouldbeestablishedforthispurpose. Verification shouldconfirmthat:

• Hazard analysis and the identification of preventive measures was carried out properly (also a checkonvalidation).

• The identification of CCPs and setting ofcriticallimitswas carriedoutprop-erly (also a checkonvalidation).

• The control of hazards at CCPs is effectiveandrecordsofCCP controlare kept.

• Monitoring methods are effectiveandmonitoringrecordsarekept.

• Corrective action procedures work effectively, that customers are protected from receiving non-conforming product and records of corrective action are kept.

• Verification procedures themselvesarecarriedoutproperly.

• Documentation covering the entire HACCP systemhasbeenestablishedand records to support the system are completedproperlyandareretainedforan appropriate periodoftime.

Because of the length of crop productioncyclesitmaybenecessarytostagger verification activities throughout the year to cover different parts of the process as they come into play. During an extended period of verification matters such as deviations from intended production processes, for example owing to unforeseen circumstances such as the weather, pests and so on, will be of particular interest, as will the implementation of preventive and corrective actions concerning such deviations. Once completed, the results of verification and any information gained from the experience of deviations may be used to modify and improve the HACCP plan.

6.6.12 Stage 12: Establish documentation and record keeping requirements (HACCP Principle 7)

A variety of documents and records are needed to develop the HACCP plan and to support the HACCP system, and a variety will result from the HACCP study. The study should yield a HACCP control chart (Table 6.2) which is central to the HACCP plan and substantially defines the operation and control of the HACCP

Table 6.2 Model of HACCP control plan for field crop production*

Monitoring*

Corrective action**

Process

CCP

Hazard

Control measure

Critical

step

no

limit(s)

Procedure

Frequency

Procedure

Seed

1

Unacceptable

Seed meets spec.

As stated in spec.

Check certificate of

Each

Reject delivery

delivery

pesticide residues in seed

analysis on delivery

delivery

Review supplier

Pesticide

2

Microbial pathogens

Use potable water

Absence of pathogens

Confirm water quality

Annually

Agree measures for

drench

in drench water

with supplier

improvement with supplier

Site

3

Contamination with

Check history of

No unrotted manure

Confirm site history

Prior to site

Use site only if free from

preparation

pathogens from

manure use on site

used in past 2 years

preparation

manure deposits or choose

unrotted manure

another site

Irrigation

4

Microbial pathogens

Use clean water

Absence of pathogens

Confirm water quality

Prior to use

Agree measures for

in water

with supplier

improvement with supplier

or use another source

Harvesting

5

Contamination with

Glass policy - only

No glass contamination

Check all glass for

Daily

Segregate and check

(glass control)

glass from machinery

use glass when needed

of product

damage

implicated product before

and care taken when

approving for use

glass involved

Harvesting

6

Contamination with

Care taken when wood

No wood contamination

Check packaging

Daily

Segregate and check

(wood control)

wood from packaging

is involved

of product

materials for damage

implicated product before

approving for use

Harvesting

7

Contamination with

Good personal hygiene

Staff adhering to

Observation and

Continuous

Appropriate management

(staff control)

microbial pathogens

practised by staff

personal hygiene

supervision of staff

of staff breaking the rules

from staff

policy

Storage

8

Growth of microbial

Select temperature and

Adequate temperature

Check storage

Daily

Segregate and check

pathogens

humidity suitable to

and humidity to

temperature and

implicated product before

prevent growth

maintain product quality,

humidity

approving for use. Rectify

but unsuitable for

temperature and humidity

microbial growth

Transport

9

Contamination with

Use only approved

Vehicles clean, hygienic

Check records of

Daily

Agree measures for

microbial pathogens

vehicles and hauliers

and fit for use

vehicle inspection

improvement with haulier

from transport

Check vehicles before

or use another approved

vehicles

use

haulier

10

Growth of microbial

Check temperature and

Temperature/humidity

Check records of

Daily

Review control procedures

pathogens

humidity suitable to

suitable to maintain

vehicle temperature

Agree measures for

prevent growth prior

product quality, but

and humidity

improvement with haulier

to despatch

unsuitable for microbial

assessment

or use another approved

growth

haulier

* A plan for soft fruit production would be similar, but with, e.g., field pesticide applications included.

** The responsibility for monitoring and corrective action would normally be given.

system. Other documents that will become part of, or will be referenced in, the plan include product specifications, purchased product specifications (covering products such a seed, agrochemicals, etc.), the process flow diagram, crop production procedures, procedures concerning preventive measures and the control of CCPs, monitoring procedures, corrective action procedures and verification procedures. Records will include CCP control records, monitoring records, corrective action records and verification records. Also, records should be kept of HACCP plan amendments and HACCP system modifications arising from validation and verification activities.

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