Attachment_14_-_CFSAN_Food_Safety_Hazards_for_FFV.pdf

Guidance for Industry

Guide to Minimize Microbial Food Safety Hazards for

Fresh Fruits and Vegetables

Additional copies are available from:

Food Safety Initiative Staff, HFS-32 U.S. Food and Drug Administration

Center for Food Safety and Applied Nutrition 200 C Street S.W.

Washington, DC 20204

(Tel) 202-260-8920 (Internet) http://www.fda.gov

U.S. Department of Health and Human Services Food and Drug Administration

Center for Food Safety and Applied Nutrition (CFSAN) October, 1998

Attachment 14 - SP3300-17-R-5001 ii

Guide to Minimize Microbial Food Safety Hazards For Fresh Fruits And Vegetables

Table of Contents

Preface

Introduction

I. Definitions

II. Water A. Microbial Hazard B. Control of Potential Hazards

1.0 Agricultural Water

1.1 General considerations

1.2 Microbial testing of agricultural water

2.0 Processing Water

2.1 General Considerations

2.2 Antimicrobial Chemicals

2.3 Wash Water

2.4 Cooling Operations

III. Manure And Municipal Biosolids A. Microbial Hazard B. Control of Potential Hazards

1.0 Municipal Biosolids

2.0 Good Agricultural Practices for Manure Management

2.1 Treatments to Reduce Pathogen Levels

2.1.1 Passive treatments.

2.1.2 Active treatments.

2.2 Handling and Application

2.2.1 Untreated Manure

2.2.2 Treated Manure

3.0 Animal Feces

IV. Worker Health and Hygiene A. Microbial Hazards iii

B. Control of Potential Hazards

1.0 Personal Health and Hygiene

2.0 Training

3.0 Customer-Pick Operations and Road-Side Produce Stands

V. Sanitary Facilities A. Microbial Hazards B. Control of Potential Hazards

1.0 Toilet Facilities and Handwashing Stations

2.0 Sewage Disposal

VI. Field Sanitation A. Microbial Hazards B. Control of Potential Hazards

1.0 General Harvest Considerations

2.0 Equipment Maintenance

VII. Packing Facility Sanitation A. Microbial Hazard B. Control of Potential Hazards

1.0 General Packing Considerations

2.0 General Considerations for Facility Maintenance

3.0 Pest Control

VIII. Transportation A. Microbial Hazard B. Control of Potential Hazards

1.0 General Considerations

2.0 General Transport Considerations

IX. Traceback

X. Conclusion

References

Appendix i

Guide to Minimize Microbial Food Safety Hazards for

Fresh Fruits and Vegetables

Additional copies are available from:

Food Safety Initiative Staff, HFS-32 U.S. Food and Drug Administration

Center for Food Safety and Applied Nutrition 200 C Street S.W.

Washington, DC 20204

(Tel) 202-260-8920 (Internet) http://www.fda.gov

U.S. Department of Health and Human Services Food and Drug Administration

Center for Food Safety and Applied Nutrition (CFSAN) ii

October, 1998

Guidance for Industry

Guide to Minimize Microbial Food Safety Hazards For Fresh Fruits And Vegetables

Table of Contents

Preface Introduction

Use of This Guide Basic Principles

I. Definitions II. Water A. Microbial Hazard B. Control of Potential Hazards

1.0 Agricultural Water

1.1 General considerations

1.2 Microbial testing of agricultural water

2.0 Processing Water

2.1 General Considerations

2.2 Antimicrobial Chemicals

2.3 Wash Water

2.4 Cooling Operations

III. Manure And Municipal Biosolids A. Microbial Hazard B. Control of Potential Hazards

1.0 Municipal Biosolids

2.0 Good Agricultural Practices for Manure Management

2.1 Treatments to Reduce Pathogen Levels

2.1.1 Passive treatments.

2.1.2 Active treatments.

2.2 Handling and Application

2.2.1 Untreated Manure

2.2.2 Treated Manure

3.0 Animal Feces

IV. Worker Health and Hygiene A. Microbial Hazards B. Control of Potential Hazards

1.0 Personal Health and Hygiene

2.0 Training

3.0 Customer-Pick Operations and Road-Side Produce Stands

iii

V. Sanitary Facilities A. Microbial Hazards B. Control of Potential Hazards

1.0 Toilet Facilities and Handwashing Stations

2.0 Sewage Disposal

VI. Field Sanitation A. Microbial Hazards B. Control of Potential Hazards

1.0 General Harvest Considerations

2.0 Equipment Maintenance

VII. Packing Facility Sanitation A. Microbial Hazard B. Control of Potential Hazards

1.0 General Packing Considerations

2.0 General Considerations for Facility Maintenance

3.0 Pest Control

VIII. Transportation A. Microbial Hazard B. Control of Potential Hazards

1.0 General Considerations

2.0 General Transport Considerations

IX. Traceback X. Conclusion References Appendix

1This document has been prepared as guidance by the Food and Drug Administration (FDA) and the USDA. This guidance represents the current thinking of FDA and USDA on a number of microbial food safety hazards and on good agricultural and management practices common to the growing, packing, and transport of most fresh fruits and vegetables. It does not create or confer any rights for or on any person and does not operate to bind FDA or USDA or the public. The agencies encourage growers, packers, and shippers to use the general recommendations in this guidance to tailor food safety practices appropriate to their particular operations. An alternative approach may be used if such approach would effectively serve to reduce microbial hazards that could result in foodborne illness and if such approach satisfies applicable statutes and regulations.

Guidance for Industry1

GUIDE TO MINIMIZE

MICROBIAL FOOD SAFETY HAZARDS

FOR FRESH FRUITS AND VEGETABLES

PREFACE

Fresh fruits and vegetables are important to the health and well being of the American consumer. Consumers enjoy one of the safest supplies of fresh produce in the world. However, over the last several years, the detection of outbreaks of foodborne illness associated with both domestic and imported fresh fruits and vegetables has increased. In a January 1997 radio address, President Clinton announced a Food Safety Initiative to improve the safety of the nation's food supply (Ref. 1). In May of 1997, as part of the President's Food Safety Initiative, the Department of Health and Human Services, the U.S. Department of Agriculture (USDA), and the Environmental Protection Agency (EPA) sent to the President a report that identified produce as an area of concern (Ref. 2). On October 2, 1997, President Clinton announced a plan entitled "Initiative to Ensure the Safety of Imported and Domestic Fruits and Vegetables" (produce safety initiative) to provide further assurance that fruits and vegetables consumed by Americans, whether grown domestically or imported from other countries, meet the highest health and safety standards (Ref. 3). As part of this initiative, the President directed the Secretary of Health and Human Services, in partnership with the Secretary of Agriculture and in close cooperation with the agricultural community, to issue guidance on good agricultural practices (GAPs) and good manufacturing practices (GMPs) for fruits and vegetables (Ref. 3).

In response to this directive, the FDA and USDA are issuing "Guidance for Industry -- Guide to Minimize Microbial Food Safety Hazards for Fresh Fruits and Vegetables." This guidance document ("the guide") addresses microbial food safety hazards and good agricultural and management practices common to the growing, harvesting, washing, sorting, packing, and transporting of most fruits and vegetables sold to consumers in an unprocessed or minimally processed (raw) form. This voluntary, science-based guidance can be used by both domestic and foreign fresh fruit and vegetable producers to help ensure the safety of their produce. The

2FDA and USDA, “Initiative to Ensure the Safety of Imported and Domestic Fruits and Vegetables: Status Report,” February 24, 1998.

voluntary guidance is consistent with U.S. trade rights and obligations and will not impose unnecessary or unequal restrictions or barriers on either domestic or foreign producers.

The produce guide is guidance and it is not a regulation. As guidance and if applied as appropriate and feasible to individual fruit and vegetable production operations, the guide will help to minimize microbial food safety hazards for fresh produce. Because it is guidance, and not a regulation, the guide does not have the force and effect of law and thus is not subject to enforcement. Operators should use the general recommendations in this guide to tailor food safety practices appropriate to their particular operations. In no case do the recommendations in this guide supercede applicable Federal, state, or local laws or regulations for U.S. operators.

Operators outside of the U.S. should follow corresponding or similar standards, laws or regulations.

The guide is one of the first steps under the President's produce safety initiative to improve the safety of fresh produce as it moves from the farm to the table. The guide focuses on the production and packing of fresh produce. However, the food safety initiative is not limited to the farm. It will focus on all stages of the farm-to-table food chain. For example, FDA's Food Code provides advice and information to state and local agencies about safe food handling practices in grocery stores, institutions, restaurants, and other retail establishments (Ref. 4). FDA is also actively seeking assistance from the Conference for Food Protection (a consortium of state, local and Federal agencies, academia, and consumer and industry representatives) in identifying practical interventions that may assist in reducing or eliminating microbial contamination of fresh produce at the retail level. In addition, as part of the President's food safety initiative, educational outreach programs, such as the recently initiated "Fight Bac" campaign, will promote improved safe food handling by consumers.

Identifying and supporting research priorities designed to help fill gaps in food safety knowledge is another focus of the food safety initiative.2 In the longterm, research and risk assessment on fresh produce will be incorporated in the multi-year food safety initiative research planning process. The overall goal of research is development of cost-effective intervention and prevention strategies to reduce the incidence of foodborne illness. Research will also support development of improved detection methods targeted to sources of contamination.

Growers, packers, and shippers are urged to take a proactive role in minimizing food safety hazards potentially associated with fresh produce. Being aware of, and addressing, the common risk factors outlined in this document will result in a more effective, cohesive response to emerging concerns about the microbial safety of fresh fruits and vegetables. Furthermore, operators should encourage the adoption of safe practices by their partners along the farm-to-table food chain, including transporters of produce, such as distributors, exporters, importers, retailers, food service operators, and consumers, to ensure that each individual effort will be enhanced.

INTRODUCTION

The importance and influence of the diet on health is undisputed. Several chronic diseases of major public health concern in the U.S., such as coronary heart disease and some types of cancer, are associated with dietary excess or imbalance. Current dietary guidelines from Federal government agencies and nationally recognized health professional organizations recommend decreased consumption of fats (especially saturated fat) and cholesterol, maintenance of desirable body weight, and increased consumption of fruits and vegetables (five or more servings daily) and grain products (six or more servings daily). Recognition of the importance of routine fruit and vegetable consumption, together with the marked increase in the year-round availability of fresh produce from a global market, has contributed to the substantial increase in consumption of fresh fruits and vegetables in the United States over the past two decades.

Whereas the health benefits associated with regular consumption of fresh fruits and vegetables have been clearly demonstrated, an increasing– though still small– proportion of reported outbreaks of foodborne illness are traced to fresh produce (Ref. 15). Recent outbreaks of foodborne illness associated with produce, including E. coli O157:H7 in mesclun mix lettuce and Cyclospora in imported raspberries, have raised concerns regarding the potential safety of fruits and vegetables that are not subsequently processed to reduce or eliminate pathogens. However, no estimates are available on the incidence and prevalence of foodborne infection associated with the consumption of fresh produce.

Use of This Guide

Because of the diversity of agricultural practices and commodities, practices recommended to minimize microbial contamination will be most effective when adapted to specific operations.

This guide is intended to assist the U.S. and foreign produce industry in enhancing the safety of domestic and imported produce by addressing common areas of concern in the growing, harvesting, sorting, packing, and distribution of fresh produce. The guide identifies the broad microbial hazards associated with each area of concern, the scientific basis of that concern, and good agricultural and management practices for reducing the risk of microbial contamination in fresh produce.

The scientific basis for reducing or eliminating pathogens in an agricultural setting is evolving and not yet complete. Thus, the examples of good agricultural practices and good management practices presented in the guide may not apply to all types of fresh and minimally processed produce and are intended to be implemented where appropriate by all industry operators.

Therefore, the examples are intended to build broad industry understanding and awareness of those practices that individual growers, packers, and shippers may consider and incorporate in their own operations. Because of the diversity of agricultural production practices and commodities, procedures recommended to minimize microbial contamination will be most effective when these general concepts are adapted to specific operations.

Government agencies recognize that the agricultural community has made a significant effort to adjust and adopt good agricultural practices to help minimize microbial food safety hazards in produce. Several fresh fruit and vegetable trade organizations, universities, state and local government agencies, and countries exporting produce to the United States have taken strong leadership roles in assisting growers, packers, and shippers in identifying potential hazards associated with their operations. These efforts have included the development of quality assurance programs, good manufacturing practices, and good agricultural and management practice guidance documents; funding of agriculture research studies; and sponsoring educational initiatives. The intent of the guide is to build on those earlier and continuing efforts and to develop national guidelines to enhance the consistency and scientific basis of food safety initiatives throughout the country.

This document represents generally accepted, broad-based agricultural guidance, developed from current knowledge of food safety practices of FDA, USDA, and others. It was developed in cooperation with experts from several Federal and state government agencies and the fresh produce industry. The guide cannot address all microbiological hazards potentially associated with fresh produce, but it can provide the framework for identifying and implementing appropriate measures most likely to minimize risk on the farm, in the packinghouse, and during transport.

There are several important considerations to remember when using this guide.

1) The guide focuses on microbial hazards for fresh produce. The guide does not specifically address other areas of concern to the food supply or the environment (such as pesticide residues or chemical contaminants). In evaluating the recommendations in this guide that are most appropriate for reducing microbial hazards in their individual operations, growers, packers, and shippers should strive to establish practices that do not inadvertently increase other risks to the food supply or the environment (e.g., excessive packaging or improper use and disposal of antimicrobial chemicals).

2) The guide focuses on risk reduction not risk elimination. Current technologies cannot eliminate all potential food safety hazards associated with fresh produce that will be eaten raw.

3) The guide provides broad, scientifically based principles. Operators should use the guide to help assess microbiological hazards within the context of the specific conditions (climatic, geographical, cultural, economic) that apply to their own operation and implement appropriate and cost effective risk reduction strategies.

4) As new information and technological advances expand the understanding of those factors associated with identifying and reducing microbial food safety hazards, the agencies will take steps (such as revising this guide or providing supplements or additional guidance documents, as appropriate) to update the recommendations and information contained in this guide.

Operators are encouraged to seek additional advice from their state and local Departments of Public Health, Environment, Agriculture, extension services and Federal agencies.

Basic Principles

Use the general recommendations in this guide to develop the most appropriate good agricultural and management practices for your operation.

This guidance document is based upon certain basic principles and practices associated with minimizing microbial food safety hazards from the field through distribution of fresh fruits and vegetables.

By identifying basic principles of microbial food safety within the realm of growing, harvesting, packing, and transporting fresh produce, users of this guide will be better prepared to recognize and address the principal elements known to give rise to microbial food safety concerns.

Principle 1. Prevention of microbial contamination of fresh produce is favored over reliance on corrective actions once contamination has occurred.

Principle 2. To minimize microbial food safety hazards in fresh produce, growers, packers, or shippers should use good agricultural and management practices in those areas over which they have control.

Principle 3. Fresh produce can become microbiologically contaminated at any point along the farm-to-table food chain. The major source of microbial contamination with fresh produce is associated with human or animal feces.

Principle 4. Whenever water comes in contact with produce, its source and quality dictates the potential for contamination. Minimize the potential of microbial contamination from water used with fresh fruits and vegetables.

Principle 5. Practices using animal manure or municipal biosolid wastes should be managed closely to minimize the potential for microbial contamination of fresh produce.

Principle 6. Worker hygiene and sanitation practices during production, harvesting, sorting, packing, and transport play a critical role in minimizing the potential for microbial contamination of fresh produce.

Principle 7. Follow all applicable local, state, and Federal laws and regulations, or corresponding or similar laws, regulations, or standards for operators outside the U.S., for agricultural practices.

Principle 8. Accountability at all levels of the agricultural environment (farm, packing facility, distribution center, and transport operation) is important to a successful food safety program.

There must be qualified personnel and effective monitoring to ensure that all elements of the program function correctly and to help track produce back through the distribution channels to the producer.

I. DEFINITIONS

The following definitions are applicable to this guidance document.

Agricultural water refers to water used in the growing environment (for example, field, vineyard, or orchard) for agronomic reasons. It includes water used for irrigation, transpiration control (cooling), frost protection, or as a carrier for fertilizers and pesticides. Occasionally a more specific term may be used, such as "irrigation water." Typical sources of agricultural water include flowing surface waters from rivers, streams, irrigation ditches, open canals, impoundments (such as ponds, reservoirs, and lakes), wells, and municipal supplies.

Adequate means that which is needed to accomplish the intended purpose in keeping with good practice.

Clean means that food or food-contact surfaces are washed and rinsed and are visually free of dust, dirt, food residues, and other debris.

Composting refers to a managed process in which organic materials, including animal manure and other wastes, are digested aerobically or anaerobically by microbial action.

Control means (a) to manage the conditions of an operation in order to be consistent with established criteria, and (b) to follow correct procedures and meet established criteria.

Control measure means any action or activity that can be used to prevent, reduce, or eliminate a microbiological hazard.

Facility means the buildings and other physical structures used for or in connection with the harvesting, washing, sorting, storage, packaging, labeling, holding, or transport of fresh produce.

Food-contact surfaces are those surfaces that contact fresh produce and those surfaces from which drainage onto the produce or onto surfaces that contact the produce may occur during the normal course of operations. "Food-contact surfaces" includes equipment, such as containers and conveyor belts that contact fresh produce, used in harvesting, post harvesting, and packing operations. It would not include tractors, forklifts, handtrucks, pallets, etc. that are used for handling or storing large quantities of contained or packed fresh produce and that do not come into actual contact with the food.

Fresh fruits and vegetables refers to fresh produce that is likely to be sold to consumers in an unprocessed or minimally processed (i.e., raw) form. Fresh produce may be intact, such as strawberries, whole carrots, radishes, and fresh market tomatoes, or cut during harvesting, such as celery, broccoli, and cauliflower. The guidance in this document is also applicable to "fresh cut" produce, such as pre-cut, packaged, ready-to-eat salad mixes. However, some fresh produce specialty items, such as fresh cut produce, may be subject to additional processing steps and/or handling that may warrant consideration of specific good manufacturing practices in addition to the good agricultural and management practices covered in this guidance document.

Good management practices refers to general practices to reduce microbial food safety hazards.

The term may include both "good agricultural practices" used in growing, harvesting, sorting, packing, and storage operations and "good manufacturing practices" used in sorting, packing, storage, and transportation operations.

Microorganisms includes yeasts, molds, bacteria, protozoa, helminths (worms), and viruses.

Occasionally, the term "microbe" or "microbial" is used instead of the term "microorganism."

Microbial hazard means occurrence of a microorganism that has the potential to cause illness or injury.

Municipal biosolids (biosolids) are the by-product of human waste treatment by local government that may be used as fertilizer or as a soil amendment.

Operator means the person or persons who have day-to-day responsibility for the production, harvesting, washing, sorting, cooling, packaging, shipping, or transportation of fresh fruits and vegetables, and responsibility for management of all employees who are involved in each of these activities.

Pathogen means a microorganism capable of causing disease or injury.

Pest refers to any animal or insect of public health importance including, but not limited to, birds, rodents, cockroaches, flies, and larvae, that may carry pathogens that can contaminate food.

Processing water means water used for post-harvest treatment of produce, such as washing, cooling, waxing, and product transport.

Sanitize means to treat clean produce by a process that is effective in destroying or substantially reducing the numbers of microorganisms of public health concern, as well as other undesirable microorganisms, without adversely affecting the quality of the product or its safety for the consumer.

Sanitize (food contact surfaces) means to adequately treat clean food-contact surfaces by a process that is effective in destroying or substantially reducing the numbers of microorganisms of public health concern, as well as other undesirable microorganisms, without adversely affecting the quality of the involved product or its safety for the consumer. It means the application of cumulative heat or chemicals on cleaned food-contact surfaces that, when evaluated for efficacy, is sufficient to reduce populations of representative microorganisms by 5 log or 99.999% (Ref. 4).

Transporter means the operator of a conveyance such as a truck, railcar, vessel, or aircraft used to transport fresh produce from grower to market.

II. WATER

Wherever water comes into contact with fresh produce, its quality dictates the potential for pathogen contamination.

Water use in crop production involves numerous field operations including irrigation, applications of pesticides and fertilizers, cooling, and frost control. Post-harvest uses include produce rinsing, cooling, washing, waxing, and transport. Water of inadequate quality has the potential to be a direct source of contamination and a vehicle for spreading localized contamination in the field, facility, or transportation environments. Wherever water comes in contact with fresh produce, its quality dictates the potential for pathogen contamination. If pathogens survive on the produce, they may cause foodborne illness.

A. Microbial Hazard Water can be a carrier of many microorganisms including pathogenic strains of Escherichia coli, Salmonella spp., Vibrio cholerae, Shigella spp., Cryptosporidium parvum, Giardia lamblia, Cyclospora cayetanensis, Toxiplasma gondii, and the Norwalk and hepatitis A viruses. Even small amounts of contamination with some of these organisms can result in foodborne illness.

As discussed in Section V. (Traceback), it is often difficult to identify with certainty the source of microbial contamination for fresh produce. It is not currently known what proportion of produce may become contaminated by water used in agricultural or packing facility operations.

However, research has shown that the use of contaminated irrigation water can increase the frequency of pathogen isolation from harvested produce (Refs. 5 and 6). In 1990 and 1993, two outbreaks, involving at least 300 cases in four states attributed to Salmonella species, were linked to consumption of fresh tomatoes (Refs. 7 and 8). Tomatoes from both outbreaks were traced back to a single packing facility where a water-bath appeared to be the likely source of contamination. Growers and packers are urged to take a proactive role in minimizing those microbial hazards over which they have some control.

B. Control of Potential Hazards

In general, the quality of water in direct contact with the edible portion of produce may need to be better than the quality of water in which contact with the edible portion of the plant is minimal.

The quality of water, how and when it is used, and the characteristics of the crop influence the potential for water to contaminate produce. In general, the quality of water in direct contact with the edible portion of produce may need to be of better quality compared to uses where there is minimal contact. Other factors that influence the potential for contact with waterborne pathogens, and their likelihood of causing foodborne illness, include the condition and type of crop, the amount of time between contact and harvest, and post-harvest handling practices.

Produce that has a large surface area (such as leafy vegetables) and that with topographical features (such as rough surfaces) that foster attachment or entrapment may be at greater risk from pathogens, if they are present, especially if contact occurs close to harvest or during post-harvest handling. Some sectors of the produce industry use water containing antimicrobial chemicals to maintain water quality or minimize surface contamination.

Operators should consider the following issues and practices when assessing water quality and in applying controls to minimize microbial food safety hazards. Not all of the following recommendations will be applicable or necessary for all operations. Rather, growers and packers should select practices, or combinations of practices, appropriate to their operations and the quality of their water supply, to achieve food safety goals.

1.0 Agricultural Water

Water quality should be adequate for its intended use. Where water quality is unknown or cannot be controlled, growers should use other good agricultural practices to minimize the risk of contamination.

Agricultural water quality will vary, particularly surface waters that may be subject to intermittent, temporary contamination, such as waste water discharge or polluted runoff from upstream livestock operations. Ground water that is influenced by surface water, such as older wells with cracked casings, may also be vulnerable to contamination. Practices to help ensure adequate water quality may include ensuring that wells are properly constructed and protected, treating water to reduce microbial loads, or using alternative application methods that reduce or avoid water-to-produce contact. The feasibility of these and other practices will depend on available water sources, the intended water use and the needs and resources of the particular produce operation.

1.1 General considerations

!! Identify the source and distribution of water used and be aware of its relative potential for being a source of pathogens.

Typical sources of agricultural water include flowing surface waters from rivers, streams, irrigation ditches, and open canals; impoundments such as ponds, reservoirs, and lakes;

groundwater from wells; and municipal supplies. It is generally assumed that groundwater is less likely to be contaminated with high levels of pathogens than surface water. Under certain conditions, shallow wells and improperly constructed or older wells may be under the influence of surface water and thus more likely to be susceptible to contamination.

!! Maintain wells in good working condition.

Growers with older wells (e.g., wells constructed 30 – 40 years ago, and especially wells constructed before 1925), or who have other reasons for concern about the condition of their well and possible contamination, may want to have their well examined by a water quality expert. Programs available from County Extension Offices, and state and local Public Health and Environmental Protection Agencies may help growers determine the condition of their wells.

!! Review existing practices and conditions to identify potential sources of contamination.

Agricultural water can become contaminated, directly or indirectly, by improperly managed human or animal waste. Human contamination may occur from improperly designed or malfunctioning septic systems and sewage treatment facility discharges such as combined sewer overflows and storm sewer overflows. Examples of on-site sources of contamination from animal waste are animal pasturing in growing areas; manure storage adjacent to crop fields; leaking or overflowing manure lagoons; uncontrolled livestock access to surface waters, wells, or pump areas; and high concentrations of wildlife. These and other potential sources of water contamination should be assessed and controlled to the extent feasible to minimize microbial food safety hazards.

!! Be aware of current and historical use of land.

Agricultural water is frequently a shared resource. In some regions, agricultural water comes from surface waters that travel some distance before reaching the produce growing area.

While growers may not have control over factors that affect the watershed, awareness of potential problems helps determine which control options are most appropriate. In assessing water quality, operators should consider what affects their portion of the watershed. Growers may consider questions such as:

-What is the prevalence of animal production in the region?

- Do feedlots, animal pastures, and dairy operations in the region use fences or other barriers to minimize animal access to shared water sources?

- Is manure applied to land by many farms in the region?

- Do local rainfall patterns and topography impact the likelihood of contaminated runoff from these operations reaching surface waters?

- Are controls generally in place to minimize contamination of agricultural waters from other farm or animal operations?

At the individual field, orchard, or vineyard level, the topography of the land and current and historical use of adjacent lands all affect the potential for water to become contaminated, if pathogens are present, and for spreading pathogens to fruits and vegetables. Growers should evaluate their production areas in terms of their proximity to surrounding land uses that pose a potential for polluted runoff from heavy rainfall.

!! Consider practices that will protect water quality.

As mentioned above, growers may not have control over factors that affect the watershed.

However, where a potential source of microbial contamination can be identified and controlled, growers should consider practices to protect the quality of agricultural water.

Good agricultural practices may include protecting surface waters, wells, and pump areas from uncontrolled livestock or wildlife access to limit the extent of fecal contamination. Soil and water conservation practices such as grass/sod waterways, diversion berms, runoff control structures, and vegetative buffer areas may help prevent polluted runoff water from contaminating agricultural water sources and produce crops.

!! Consider irrigation water quality and use.

There is general scientific agreement that irrigation practices that expose the edible portion of plants to direct contact with contaminated water may increase microbial food safety risks (Ref. 10), especially for those crops and regions where irrigation is likely to occur close to harvest. To the extent feasible, growers should follow good agricultural practices that minimize the potential for contaminated water to contact the edible portion of the crop .

Irrigation needs will vary with crop and region. Growers should first concentrate on protecting and maintaining water quality. However, where water quality is unknown or cannot be controlled, growers may want to consider irrigation practices that minimize contact between water and the edible portion of the crop. Where available and appropriate, growers may want to consider low volume sprays, drip, furrow, or underground irrigation as part of their overall program. Alternative approaches may also be used. Conversely, if knowledge or testing indicates water quality is good (such as water from properly constructed wells or municipal water supplies), the risk of water serving as a direct source of microbial contamination is low, regardless of the type of irrigation system used. Further, for some crops, such as root crops or low growing crops, it may not be possible to effectively minimize contact between irrigation water and the edible portion of the crop.

1.2 Microbial testing of agricultural water

There are a number of gaps in the science upon which to base a microbial testing program for agricultural water and microbial testing of agricultural water may be of limited usefulness.

Growers concerned about water quality should first focus their attention on good agricultural practices (such as manure management and runoff controls) to maintain and protect the quality of their water sources. Growers interested in testing the microbial quality of agricultural water sources may want to consider the following:

- Growers may elect to test their water supply for microbial contamination on a periodic basis, using standard indicators of fecal pollution, such as E. coli tests, which may be performed by commercial, State, or local government laboratories. However, bacterial safety of water does not necessarily indicate the absence of protozoa and viruses.

- Where agricultural water comes from public sources, information on microbial analysis of the water may be available from the local water authority.

- Water quality, especially surface water quality, can vary with time (e.g., seasonally or even hourly), and a single test may not indicate the potential for water to be contaminated.

Furthermore, testing water may not reveal specific pathogens if they are present in low numbers. However, appropriate microbiological testing may be useful for confirming water quality concerns in extreme situations (e.g., polluted water source) and in assessing the effectiveness of certain control programs (e.g., clean-up of well water).

- Growers can consult local water quality experts, such as state or local Environmental Protection or Public Health agencies, extension agents or land grant universities, for advice appropriate for individual operations.

2.0 Processing Water

Processing water should be of such quality that it does not contaminate produce.

Water used during the post-harvest handling of fruits and vegetables often involves a high degree of water-to-produce contact. Although water is a useful tool for reducing potential contamination, it may also serve as a source of contamination or cross-contamination. Reusing processing water may result in the build-up of microbial loads, including undesirable pathogens from the crop. Operators should institute practices to ensure that water quality is adequate for its intended use, both at the start and at the end of all post-harvest processes.

2.1 General Considerations

!! Follow good manufacturing practices to minimize microbial contamination from processing water.

- Water quality needs may vary depending on where the water use falls within the series of processes and whether a particular process is followed by additional cleaning processes. For example, water quality needs may be greater for water used for a final rinse before packaging compared with water in a dump tank where field soil from arriving produce quickly mixes with the water.

- Water quality consistent with U.S. EPA requirements for drinking water, or similar standards, is recommended (Currently, the Total Coliform Rule and the Surface Water Treatment Rule, See Appendix 2 for information on obtaining copies of EPA rules and regulations). While water quality management may vary throughout all operations, packers should follow good manufacturing practices to minimize the potential for the introduction or spread of pathogens via processing water. Water that meets the microbial standards for drinking water is considered "safe and sanitary."

- Where water is reused for a series of processes, it is recommended that whenever possible, water flow counter to the movement of produce through the different unit operations. For example, water might be used first in a final rinse then reused in an earlier unit operation, such as a dump tank.

- Good Manufacturing Practices (GMPs) for water used for food and food contact surfaces in processing facilities are in Title 21 of the Code of Federal Regulations (CFR), sections 110.37(a) and 110.80(a)(1). 21 CFR 110.19 provides an exemption from the requirements in 21 CFR part 110 for establishments engaged solely in the harvesting, storage, or distribution of raw agricultural commodities. However, U.S. operators using water for post-harvest operations in the field or packing facility are encouraged to consider those good manufacturing practices in part 110, that are applicable to their operations. Foreign operators are encouraged to consider corresponding or similar provisions. (See Appendix 2 for information on how to order copies of the CFR.)

!! Consider practices that will ensure and maintain water quality.

Such practices may include:

- Perform periodic water sampling and microbial testing;

- Change water as necessary to maintain sanitary conditions. Consider developing SOPs (standard operating procedures or sanitary operating plans), including water change schedules, for all processes that use water;

- Clean and sanitize water contact surfaces, such as dump tanks, flumes, wash tanks, and hydrocoolers, as often as necessary to ensure the safety of produce;

- Install backflow devices and legal air gaps, as needed, to prevent contamination of clean water with potentially contaminated water (such as between potable water fill lines and dump tank drain lines; and

- Routinely inspect and maintain equipment designed to assist in maintaining water quality, such as chlorine injectors, filtration systems, and backflow devices, to ensure efficient operation.

Prevention of contamination is preferred over application of antimicrobial chemicals after contamination occurs.

2.2 Antimicrobial Chemicals

Prevention of contamination is preferred over corrective actions once contamination has occurred. However, antimicrobial chemicals in processing water are useful in reducing microbial build-up in water and may reduce microbial load on the surface of produce. Thus, antimicrobial chemicals may provide some assurance in minimizing the potential for microbial contamination.

The effectiveness of an antimicrobial agent depends on its chemical and physical state, treatment conditions (such as water temperature, acidity [pH], and contact time), resistance of pathogens, and the nature of the fruit or vegetable surface. Chlorine, for example, is commonly added to water at 50 - 200 ppm total chlorine, at a pH of 6.0 - 7.5, for post-harvest treatments of fresh produce, with a contact time of 1 - 2 minutes.

Ozone has been used to sanitize wash and flume water in packinghouse operations.

Ultraviolet radiation may also be used to disinfect processing water. Chlorine dioxide, trisodium phosphate, and organic acids (such as lactic and acetic acids) have been studied for use as antimicrobial agents in produce wash water, although more research needs to be done. Operators should consider options for water sanitation most appropriate for their individual operations.

- All chemical substances that disinfect wash water and contact food must be used in accordance with FDA and EPA regulations. Operators outside the U.S. should follow corresponding or similar national or regional laws or regulations. (See Appendix 2 for information on obtaining copies of FDA and EPA regulations.)

- Operators should carefully read antimicrobial chemical labels, regulations, and other relevant information. Operators should follow manufacturers’ directions for correct mixing of antimicrobial chemicals to obtain effective concentrations and to minimize safety hazards.

Operators should not exceed recommended levels and must not exceed allowable levels of antimicrobial chemicals in wash water. Excessive concentrations of antimicrobial chemicals (such as chlorine) can damage equipment, reduce produce quality, be harmful to worker health, and may pose a hazard to consumers.

- Antimicrobial chemical levels should be routinely monitored and recorded to ensure that they are maintained at appropriate concentrations. Other parameters (such as pH, temperature, and oxidation reduction potential [ORP]) that indicate levels of active agents or that affect the effectiveness of the antimicrobial used, should also be monitored and recorded. Operators should establish SOPs for monitoring, recording, and maintaining antimicrobial chemical levels.

- As organic materials and microbial load increases in wash water, the efficacy of antimicrobial chemicals decreases, rendering them inactive against microorganisms. For some operations, filtering recirculating water or using a net to scoop plant material or debris from tank surfaces, may help reduce the build-up of organic material.

-Surface treatments with some antimicrobial chemicals may need to be followed by a clean water rinse to remove any treatment residues.

-Operators should contact chemical companies that sell antimicrobial chemicals for additional technical assistance.

2.3 Wash Water

Washing fresh produce (also known as surface treatment) can reduce the overall potential for microbial food safety hazards. This is an important step since most microbial contamination is on the surface of fruits and vegetables. If pathogens are not removed, inactivated, or otherwise controlled, they can spread to surrounding produce, potentially contaminating a greater proportion of the produce.

A number of post-harvest processes, such as hydrocooling, use of dump tanks, and flume transport, involve a high degree of water-to-produce contact. Packers should follow good manufacturing practices to maximize the potential for these processes to assist in cleaning produce.

!! Use appropriate wash methods.

- Vigorous washing of produce not subject to bruising or injury may increase the likelihood of pathogen removal. Brush washing is more effective than washing without brushes. Brushes used in brush washing must be cleaned frequently.

- Different methods are used to wash different types of produce, including submersion, spray, or both. Spray wash treatments may be less likely to directly spread microbial contaminants.

However, spray wash treatments may spread pathogens by splashing or by aerosol, or on food contact surfaces, such as brushes and utensils. Further, if water is contaminated during washing and then reused, it can be a vehicle for spreading contamination. Therefore, regardless of wash method used, operators are encouraged to follow good management practices that ensure and maintain adequate water quality.

!! Maintain the efficacy of wash treatments.

Wash water, even with antimicrobial chemicals, likely reduces but may not eliminate pathogens on the surface of produce. Antimicrobial washes generally reduce microbial populations by 10– to 100-fold. Operators should adopt practices to maintain the efficacy of wash treatments.

-For some operations, a series of washes may be more effective than a single wash. For example, packers may consider using an initial wash treatment to remove the bulk of field soil from produce followed by additional washes and/or a sanitizing dip and a final fresh, clean water rinse.

!! Consider the wash water temperature for certain produce.

- Removing field heat is a primary consideration in maintaining the quality of many types of produce. However, for some types of produce (apples, celery, tomatoes) the temperature of wash water should be greater than that of the produce or a pressure differential results that can cause water to be pulled into the plant material, causing pathogens that may be present on the produce surface or in the water to be internalized. If pathogens are pulled into the produce, washing is unlikely to reduce these pathogens (Refs. 9 and 10). Denser products (such as carrots) do not appear to be affected by water temperature differences. For products that may be susceptible to internalization of pathogens, the recommended temperature differential may be achieved either by heating water or by air cooling produce before immersion.

- When it is not practical to expose produce to warmer water temperatures, good manufacturing practices to minimize pathogens in the water or on the surface of produce are especially important. Such practices may include using antimicrobial chemicals in the wash water, using spray-type wash treatments instead of submerging produce, and ensuring that both produce and water are clean before produce is submerged.

!! Consider alternative treatments for water-sensitive produce.

- Dry cleaning (e.g., brushing, scraping, blowing air) may be used with some produce that cannot tolerate water. In these cases, periodic equipment clean up and sanitation will reduce the potential for cross-contamination.

- Treatment of produce with ionizing radiation at doses up to 1 kGy (1 kiloGray or 100 krad) is permitted for inhibition of ripening or sprouting, and for insect control (21 CFR 179.26).

At these doses, there would also be some reduction in pathogens that may be present. The extent of any reduction will be dependent on the radiation sensitivity of the particular pathogen as well as the actual dose used. For example, doses needed to achieve a 10-fold reduction in Salmonella are typically higher than those needed to achieve the same reduction in E. coli O157:H7. The actual effectiveness of any low-dose radiation treatment in pathogen control will, in addition, be strongly dependent on the load initially present.

2.4 Cooling Operations

Various methods are available for cooling produce, including water, ice, and forced air. The method used depends on the fruit or vegetable and the resources of the operator. In most instances, cooling with air (such as vacuum coolers or fans) will pose the lowest risk.

Water and ice used in cooling operations should be considered a potential source of pathogenic contamination. Further, reuse of water to cool continuous loads of produce increases the risk of cross-contamination. For example, contaminated produce from a single container going through a cooling process may result in the build-up of pathogens over time in the cooling water supply. Operators should follow good management practices to ensure that chilling does not introduce food safety hazards. Practices may include the following.

!! Maintain temperatures that promote optimum produce quality.

The benefits of chilling to remove field heat and the temperature requirements for optimum keeping quality vary for different types of produce. Adequate refrigeration, in conjunction with crop characteristics, such as pH, is an important safeguard against many pathogens.

Further, good quality, intact produce is most resistant to microbial contamination and growth.

Thus, maintaining temperatures that promote optimum product quality may reduce the risk of microbial hazards.

!! Maintain air cooling equipment and cooling areas.

Air cooling equipment and cooling areas should be periodically cleaned and inspected.

Potential sources of contamination should not be located near air intakes.

!! Consider the…