This guidance represents the Food and Drug Administration's (FDA's) current thinking on this topic. It does not create or confer any rights for or on any person and does not operate to bind FDA or the public. You can use an alternative approach if the approach satisfies the requirements of the applicable statutes and regulations.  

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Table of Contents

1. Introduction
2. Background
3. Discussion
4. References 

I. Introduction

This guidance is intended to advise food manufacturers that once a boil-water advisory has been issued they should stop using the water subject to the advisory until the water again meets the applicable federal and state drinking water quality standards. Further, this guidance is intended to assist food manufacturers in evaluating food that already was produced with water subject to the advisory.

FDA's guidance documents, including this guidance, do not establish legally enforceable responsibilities. Instead, guidances describe the Agency's current thinking on a topic and should be viewed only as recommendations, unless specific regulatory or statutory requirements are cited. The use of the word should in Agency guidances means that something is suggested or recommended, but not required. 

II. Background

Boil-water advisories are public announcements by local water authorities advising the public to boil their tap water for drinking and other human consumption uses, to protect public health from waterborne infectious agents that could be or are known to be present in drinking water. Such advisories are issued for a variety of reasons, including broken water mains and flooding that adversely impacts water treatment facilities. For example, on May 1, 2010, water service to 30 Massachusetts Water Resources Authority (MWRA) customer communities (serving approximately 2 million residents) was interrupted by a major break in a 120-inch diameter MWRA pipe that transports water to communities east of Weston, Massachusetts. MWRA later reported that the damaged section had been repaired and passed its load test, and the system is distributing water to all communities. In response to this major water break, the President issued an emergency declaration (FEMA-3312-EM) to facilitate Federal assistance to the Commonwealth of Massachusetts for emergency protective measures. On May 4, 2010, the boil-water advisory was lifted, and the Governor of Massachusetts announced that water was once again clean and safe for all purposes. FDA worked in concert with the United States Department of Agriculture and MWRA to address issues related to the affected food industry. 

III. Discussion

Once a boil-water advisory has been issued, food manufacturers should stop using the water subject to the advisory until the water again meets the applicable federal and state drinking water quality standards. In addition, any food produced with water subject to the advisory should be evaluated. FDA is providing recommendations to assist food manufacturers in evaluating such food.

When a boil-water advisory is issued, it is assumed that bacterial, viral and parasitic (e.g., Cryptosporidium and Giardia) contamination may have occurred. Heat treatment and, where applicable, filtration can be used to reduce or eliminate the risk from this contamination. More heat is needed to inactivate hepatitis A virus (HAV) and Cryptosporidium, which have greater heat resistance than vegetative cells of bacterial pathogens of concern. Viruses are smaller than bacterial cells, which are smaller than parasites. If filtration alone is used to ensure the safety of water, the filter must be sufficient to remove all organisms of concern. Disinfectants such as ozone, hypochlorite, chlorine dioxide or UV used in conjunction with 1 µm absolute filtration (International Bottled Water Association, 2005) are sufficient to address viruses, parasites and vegetative cells of bacterial pathogens in water. UV alone at the appropriate dose (40 CFR 141.720) will inactivate bacterial pathogens, viruses and parasites in water. Cryptosporidium is resistant to many chemical disinfectants, including chlorine (Donnelly and Stentiford, 1997); however, chlorine dioxide or ozone will inactivate this organism (40 CFR141.720).

Use of Water in Heated Foods
If water subject to the advisory was used as an ingredient in food and the product has subsequently been adequately heat treated, the food does not present a risk with respect to the water used. Cryptosporidium and HAV are the most heat resistant pathogens of concern. Based on data available to FDA for reducing Cryptosporidium in water, milk and cider (Deng and Cliver, 2001; Fayer, 1994; Harp et al., 1996) and HAV in dairy products (Bidawid et al., 2000)
FDA recommends heat treatment for 1 minute at 185ºF.

If water subject to the advisory was used as an ingredient in food or as process water and the food was not heat treated by the food manufacturer, the product may present a risk to the consumer and should not be distributed unless FDA, in consultation with the state regulatory authorities, determines that the risk is minimal and can be controlled with ordinary consumer cooking practices. FDA recommends quarantining the food until such determination has been made.

Use of Water in Ice, Bottled Water, or Ready-To-Eat Foods
Because of the possible presence of viruses, parasites or bacterial pathogens, water subject to a boil-water advisory should not be used for ice, bottled water or ready-to-eat (RTE) foods unless it is heat treated (e.g., 1 minute at 185ºF) or, in the case of water used for ice, bottled water, or other beverages, treated as indicated above.

Use of Water for Cleaning
If water subject to the advisory was used to clean equipment, utensils, or food contact surfaces, followed by a sanitizer, there is some risk from pathogens for equipment that has been cleaned and that contains residual water that may be incorporated into product that is not appropriately treated as indicated above. Food made with such equipment should not be distributed to the consumer unless the product has been treated to control the risk. Where the food manufacturer believes that sanitizing procedures may have been adequate to address the organisms of concern, they should seek a determination from FDA. FDA will, in consultation with state regulatory authorities, determine whether the risk is adequately controlled.

Although sanitizing chemicals (e.g., chlorine) may have limited efficacy for parasites, hot water sanitization can effectively reduce the pathogens of concern on equipment. If the temperature of the equipment cannot be brought to 185ºF for 1 minute, lower temperatures for longer times can be used effectively (e.g., the temperature achieved on the equipment reaches ≥170ºF for 30 min).  

Use of Water for Hand Washing
If water subject to the advisory was used for hand washing and bare hand contact of food occurred, the food should not be distributed  unless it is subjected to a treatment to adequately control the risk prior to distribution.  

Use of Water for Other Purposes
If water subject to the advisory was used where there was no contact with food and food contact surfaces, e.g., washing the floors, there is minimal risk of transfer to food. 

IV. References

We have placed the following references on display in the Division of Dockets Management, Food and Drug Administration, 5630 Fishers Lane, rm. 1061, Rockville, MD 20852. You may see them at that location between 9 a.m. and 4 p.m., Monday through Friday.

1. Bidawid, A., J.M. Farber, S.A. Sattar, and S. Hayward. 2000. Heat inactivation of hepatitis A virus in dairy foods. J. Food Protection 63: 522-528.
2. Deng, M.Q. and D.O. Cliver 2001. Inactivation of Cryptosporidium parvum oocysts in cider by flash pasteurization. J. Food Protection 64: 523-527.
3. Donnelly, J.K., and E.I. Stentiford. 1997. The Cryptosporidium problem in water and food supplies. Lebensm.-Wiss. u.-Technol. 30: 111 - 120.
4. Fayer, R. 1994. Effect of high temperature on infectivity of Cryptosporidium parvum oocysts in water. Appl. Env. Microbiol. 60: 2732-2735.
5. Harp, J.A., R. Fayer, B.A. Pesch and G.J. Jackson. 1996. Effect of pasteurization on infectivity of Cryptosporidium parvum oocysts in water and milk. Appl. Env. Microbiol. 62:2866-2868.
6. International Bottled Water Association. 2005. Plant Technical Reference Manual, Chapter 4 Water Treatment and Processing.

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Related Information

• Additional Guidance Documents & Regulatory Information on Food and Dietary Supplements