June 2003
Volume 45 Number 6

Water Coolers--The Meeting of Many Standards
by Shannon Murphy   Pages: 

Instant water dispensers have increased their visibility in the market recently. With this increase in sales and distribution, either at the local retailer or through distributors, one question has come up a number of times—into which standard or group of standards do these products fit? It’s a simple question with a multi-layered answer. In short, there are a total of three ANSI/NSF standards that apply to these products.

ANSI/NSF Standard 18
First, there’s ANSI/NSF Standard 18-Manual Food and Beverage Dispensing Equipment. Standard 18 contains requirements for the materials, design and performance of water coolers so they can be cleaned and kept sanitary. Materials are reviewed in accordance with U.S. Food and Drug Administration (FDA) regulations, specifically Title 21 of the Code of Federal Regulations (21 CFR). This includes design requirements ensure the cooler can be wiped clean, and doesn’t provide a haven for vermin. Performance requirements apply when the water contact parts of the water cooler are designed to be cleaned without disassembly. In these situations, NSF inoculates the equipment with Escherichia coli bacteria, performs in-place cleaning procedures as per the manufacturer’s instructions, and then samples the water. Samples must be below safe levels for E. coli to be considered a “pass.” The standard ensures the clean water circulating through these devices stays clean.

Standard 61, Section 9
Then there’s ANSI/NSF Standard 61, which is responsible for material health effects of drinking water system components. Standard 61, Section 9 specifically covers water-dispensing units plumbed-in to the water supply. Typically, they’ll be installed within the last liter of the distribution system. Standard 61 is a health effects standard only, and doesn’t have any structural or cleanabil-ity requirements. Products certified to Standard 61 must disclose all wetted materials within the device. Upon completion of this disclosure, products certified to Section 9 will go through an extraction process known as the 19-day dump-and-fill.

Products certified to Section 9 must also pass the statistical Q evaluation for lead, which is a value of 11 or less. Some states have requirements for a lower statistical Q value to be sold there. A statistical Q is an exact 90 percent upper confidence bound on the 75th percentile of product dosage. In more common vernacular, it’s a statistical calculation that incorporates the levels of lead extracted out of an end-point device, the decay of the extracting lead over a three-week dump-and-fill process, and the standard deviation between tested products—all normalized to one liter.

DWTU standards
Lastly, there’s the bank of ANSI/NSF Drinking Water Treatment Unit (DWTU) standards—www.nsf.org/dwtu/dwtu_standards.html—that these products can be certified, too. The specific DWTU standard(s) the product will need to meet depends upon the technology applied in the water-dispensing device, if any. There’s a requirement within DWTU standards that if a product has multiple treatment technologies, it’s required to be certified to all of the applicable standards. As an example, a carbon filter unit with an ultraviolet (UV) device needs to be certified as a system under Standards 42 and 55 as a minimum.

For a review of the extraction requirements for Standard 61 and the DWTU standards, please refer to the January 2002 Water Matters column, “Drinking Water System Components: Testing and Certifying,” by Rob Herman and Blake Stark.

Gravity-fed water dispensers
Gravity-fed water dispensers have a water bottle—typically 3- or 5-gallon—on top of the device. These products fall under the scope of ANSI/NSF Standard 18. The key item regarding these units is that they aren’t plumbed-in to the water distribution line. If the system is plumbed-in to the water line, it falls under the requirements of Standard 61 rather than Standard 18.

Gravity-fed units may provide chilled or heated water as well. In these cases, there may be an internal pump, heater, chiller or water storage tank. Provided these options maintain the system as non-plumbed-in, it remains applicable to Standard 18 only.

Plumbed-in water dispensers
Water dispensers sold with the intent to be plumbed-in to a water distribution line and dispense water that’s not treated by the device would fall under the requirements of Standard 61. These dispensers would be categorized similar to a drinking water fountain that would typically be found in schools and gymnasiums. These systems may also have a heater, chiller or internal pump as options for the water dispenser. Provided the system is plumbed-in to the water distribution system and has no treatment components, it remains under the scope of Standard 61 only.

Dispensers with internal filtration
The incorporation of water treatment can cause things to become a little more complex. Through some simple rules regarding the application of the standard(s), however, it’s more easily understood. In short, the rule is as follows—if the water dispenser is sold with an internal water filtration or treatment device, and that system is making any claims regarding use of that water filtration or treatment, it then falls under the scope of the DWTU standards. Depending upon the system, plumbed-in or gravity-fed, it may also fall under the requirements of other standards.

First, gravity-fed systems with an internal water filtration or treatment device fall under the scope of both Standard 18 and DWTU standards. Standard 18 has specific requirements not covered under any of the DWTU standards such as product cleanability. Due to these reasons, a gravity-fed water dispenser sold with an internal treatment device should be certified to Standard 18 as well as the applicable DWTU standard(s).

Next, plumbed-in water dispensers sold with an internal water treatment device generally fall under only the applicable DWTU standard, as it’s dependent on the design of the water dispenser. Water treatment devices are excluded from the scope of Standard 61 and thus need to meet only the requirements of the applicable DWTU standard. Due to the exclusion of water treatment systems from Standard 61, a plumbed-in water dispenser that provides only treated water would need to meet requirements of the applicable DWTU standard only.

An example of this would be a plumbed-in office water cooler with two dispensing outlets—ambient and chilled water. In this case, both the ambient and the chilled outlets are run through the internal water filtration device. Since the device only dispenses treated water, it’s irrelevant that the water is chilled (or heated) following the treatment of water.

Conversely, that same office water dispenser—if equipped with a third outlet for the dispensing of non-filtered water—needs to be certified under both Standard 61 and the applicable DWTU standard. Since the system has a water dispensing line that provides unfiltered water, that part of the device is looked at as meeting the requirements of Standard 61, and must be evaluated as such.

In these cases, the product is somewhat divided into two systems. The waterway that provides filtered water is certified under one of the DWTU standards while the waterway that provides unfiltered water is certified under Standard 61. There can be, and typically is, an overlap between the two waterways. Typically, there’s one inlet to the system that is then teed off and separates the filtered waterway from the non-filtered waterway. The inlet plumbing in the water dispenser is then tested and evaluated under both standards.

Kitchen filter faucets
A similar product that falls under this category is the kitchen filter faucet. These devices provide both filtered and non-filtered water. As such, these devices carry a dual certification both to Standard 61 and the applicable DWTU standard.

Fortunately, the formulation disclosure requirements for Standard 61 and the DWTU standards are similar so there’s no duplication of work regarding the gathering of material formulation information. Structurally, only the waterway that’s used for filtered water is required to meet the applicable structural requirements as defined within the applicable DWTU standard.

There has been some confusion regarding exactly what standard these instant water dispensers need to meet. By applying some rules on how to certify these units, it does become clearer on what certification path to take. Simply, non-filtered, gravity-fed systems will need to meet Standard 18. If that same device is sold with an internal filter, then it needs to meet the requirements of both Standard 18 and the applicable DWTU standard.

Plumbed-in systems that deliver water that’s not further treated by the device through at least one outlet will be certified according to Standard 61, Section 9. If the system is equipped with an internal filtering device, then the filtered water line will be certified to the applicable DWTU standard. If the system has both filtered and non-filtered water, then it will require dual certification to Standard 61, Section 9, and the applicable DWTU standard.

About the author
Shannon Murphy is operations manager of the Drinking Water Treatment Unit program at NSF International in Ann Arbor, Mich. His bachelor’s degree in biology is from Concordia University in Montreal, Canada, and his master’s degree from Wayne State University in Detroit is in biology with an emphasis on limnology. Murphy can be reached at (800) 673-6275, (734) 827-7144 (fax) or email: murphy@nsf.org