Volume 45 Number 6
Water Coolers--The Meeting of Many Standards
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
Standard 61, Section 9
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.
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 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
Dispensers with internal filtration
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
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.
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.
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