A P R I L 2 0 0 6Water Conditioning & Purification60

The Who, What, When,Why and How of the WRAS

Approval Process

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With the expansion of the inter-national market place for resi-dential drinking water treat-

ment products, there are more and morequestions surrounding what approvalsare needed in these international marketsand what the approval processes entail.International approval requirementsvary by country, so it would be difficultto address them all in a single book, letalone a single article. This article willstart with one piece of the internationalpuzzle: the who, what, when, why andhow of the WRAS approval process re-quired in the United Kingdom.

The WRAS approval process is awell-defined one, with clear guidance re-garding what information and testing isneeded to achieve WRAS approval or aWRAS certificate.

The WhoA good starting point for this topic

is to ask, “Who is WRAS and who is re-quired to have WRAS approval?”

WRAS is an abbreviation for theWater Regulations Advisory Scheme.WRAS publishes the Water Fittings Regu-lations and Northern Ireland Regulations.WRAS promotes consistent interpreta-tion of the regulations. WRAS can con-sult with government, manufacturersand installers. WRAS assists in the de-velopment of relevant standards andapproves and lists water fittings andmaterials.

Manufacturers intending to sell theirproducts in the United Kingdom and

Northern Ireland must determine ifWRAS approval is required to sell theirproduct in the U.K. While many prod-ucts are not required to have WRAS ap-proval, a significant number of endcustomers and big box stores located inthe U.K. are requiring WRAS approval.

WhatNow that we know who WRAS is,

the next question to ask about the pro-cess is, “What kind of testing is neededfor WRAS approval?” The answer is thatthe amount and type of testing neededdepends on the product type.

There are two types of approvals:materials approval and product or fittingapproval. A material approval is an ap-proval of an individual material. A prod-uct or fitting approval is an approval ofthe fitting or system. Manufacturers ofresidential water treatment productsshould keep in mind that complete wa-ter treatment systems are considered ‘fit-tings’ in WRAS terminology.

A material or system can be ap-proved for hot and cold-water use, orcold-water use.

A material or fitting tested under hotwater conditions also qualifies for cold-water use.

Both material and fitting or productapprovals require material testing. Prod-uct or fitting approvals require mechani-cal testing in addition to materialstesting.

Materials’ testing is referred to as theBS6920. The BS6920 or British Standard6920 consists of five individual tests,listed in Figure 1. Details of these testsare as follows:

By Laura Moorman

Figure 1. BS6920 materialstestingOdor and flavorAppearance of colorant and turbidityGrowth of aquatic microorganisms(also known as ‘microbial’ testing)Extraction of substances harmful to health(also known as ‘cytotoxicity’)Extraction of metals

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Odor and flavorThe purpose of odor and flavor testing is to determine if a

product imparts an odor or flavor when the material is exposedto drinking water. The odor and flavor testing is judged by athree-person panel against a control of tap water.

Appearance of colorant and turbidityThis testing determines if the product causes the water to

change color or increase in turbidity. The color is measured us-ing a color spectrum. The product cannot cause an increase incolor more than five color units. The turbidity is measured us-ing a turbidimeter, with the pass/fail criteria being that the tur-bidity of the water cannot increase more than 0.5 NTU aftercontacting the material.

Growth of aquatic microorganismsMicrobial testing determines if a product will promote sig-

nificant growth of aerobic microorganisms. The length of thetest is 7-10 weeks and the pass/fail criterion is based on themean dissolved oxygen difference (MDOD).

As the growth of aerobic mi-croorganisms increases, oxygen isremoved from the test system. Thisloss is compared with the controlsystem. Samples are taken at weeksfive, six and seven, with the MDODbeing determined as the mean valuefrom these samples. The evaluationof results is quite complicated andis described in Figure 2.

Extraction of substances harmfulto health

Cytotoxicity testing is a seven-day test and determines if a prod-uct shows toxicity to humans. If acytotoxic response is detected, twoadditional samples are tested. If theadditional samples show no cyto-toxic response, then the materialcomplies. If the additional samplesshow cytotoxic response, the material fails.

Extraction of metalsThe extraction of metals testing determines if metals are

leached into the product water. Any metal detected must notexceed the maximum ad-missible concentration(MAC). For the MAC lev-els please see Figure 3.

After all five indi-vidual tests are success-fully completed, a passingtest report is issued forthat material. That mate-

Figure 2. Interpretation of MDOD resultsMDOD result, mg/L Interpretation

<1.7 Material passes test1.7 – 2.0 Test extended by two weeks and

further MDOD samples are taken2.0 – 2.9 Re-test is required with two

additional material samples> 2.9 Material fails test

Figure 3. MAC levelsfor metals

MACMetal µg/LAluminum 200Antimony 10Arsenic 50Barium 1,000Cadmium 5Chromium 50Iron 200Lead 50Manganese 50Mercury 1Nickel 50Selenium 10Silver 10

Figure 4. WRAS mechanicaltesting requirementsSuccessful completion of the BS6920(materials testing)Pressure testingOpacityIdentifier

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rial has successfullycompleted the BS6920.For those manufacturersseeking material ap-provals, testing is com-plete and the listingreview process begins.For those manufacturersseeking fitting or prod-uct approvals, mechani-cal testing begins.

There are variousrequirements of mechanical testing de-pending on the system. This article willfocus on four basic requirements as de-scribed in Figure 4. Details of these test-ing requirements follow. Products suchas water softeners and reverse osmosissystems have additional requirements in-cluding, but not limited to, consumptionand testing of the faucet.

BS6920Mechanical testing will not com-

mence until all materials have success-fully completed the BS6920 testing.

Pressure testingPressure testing is required to ensure

the product or fitting is watertight. Theproduct or fitting must withstand pres-sure testing up to 1.5 times the product’srated pressure.

OpacityThe purpose of

opacity testing is to en-sure the product willnot promote microbialgrowth. Testing en-sures light cannot passthrough the product.

IdentifierThe identifier or la-

bel is reviewed to en-sure the product is easily identifiable.After successful completion of the BS6920and mechanical testing, the fitting orproduct’s test reports are sent to the Testand Assessment Group (TAG) of thescheme. The TAG includes representa-tives from the U.K.’s Water Supply Indus-try group. The TAG reviews all testreports and identifier and determines ifa product or fitting will receive a WRASapproval certificate. The certificate issuedis valid for five years and then re-testingis required.

WhenNow that you know who and what

the WRAS approval process entails, alogical next question for manufacturersis, “When should I start the approval pro-cess?” Depending on the when the manu-facturer would like to enter the U.K.

Figure 5. TAG submissiondates for 2006

Wednesday January 18, 2006Tuesday March 7, 2006Wednesday April 19, 2006Tuesday June 6, 2006Tuesday July 18, 2006Wednesday September 6, 2006Tuesday October 24, 2006Tuesday December 5, 2006

market, a manufacturer should refer tothe cut-off dates for submission to theTAG to determine when to begin the ap-proval process. The TAG meets approxi-mately every eight weeks. Thesubmission dates are available on thewebsite at http://www.wras.co.uk/TAG.htm and are available in Figure 5.

WhyThe next question is, “Why would

anyone need WRAS approval?” The pur-pose of WRAS is to prevent the waste,misuse, undue consumption, contamina-tion or erroneous measurement of water.But the real answer to this question is thatWRAS approval is needed for marketaccess for many products being soldthrough retail channels in the U.K.

HowThe last question: “How does a

manufacturer get started in the WRASapproval process?” There are five labo-ratories approved for testing for WRAS.To start the approval process, a manufac-turer can contact one of the approvedlaboratories. A parts list of materials issubmitted for review. The lab reviews theparts list and a determination is maderegarding which materials require test-ing. Each lab requires the same informa-tion and uses a standardized form. Therequired forms can be found on theWRAS website.

With all of the questions aboutWRAS approval asked and answered,now you know the who, what, when,why and how of the WRAS approval pro-cess. You can begin your journey into in-ternational approvals world informedand aware.

About the authorS Laura Moorman has been a certificationproject manager and senior certificationproject manager with NSF International forthree years, working with certification of resi-dential drinking water products. Her previ-ous experience was in pharmaceutical sales.Laura has had extensive training in WRASapprovals and test procedures. She has abachelor’s degree in business managementfrom Kent State University, and she can bereached at 1-800-NSF-Mark or e-mail:lmoorman@nsf.org.

About NSFS If all of this seems a bit daunting, pleasekeep in mind that manufacturers wanting aseamless interface can have NSF coordinatethe WRAS approval process for them. NSFhopes that this service will help make WRASapprovals easier, whether manufacturers careto understand all the details or not.