Frequently Asked Questions
General Questions on NSF/ANSI Standard 61
- What is NSF/ANSI Standard 61?
NSF/ANSI Standard 61 - Drinking Water System Components was published in 1988 to establish minimum requirements for the control of potential adverse human health effects from products that contact drinking water.
NSF/ANSI Standard 61 includes criteria for testing and evaluating products to ensure they do not leach contaminants into the water that would be a health concern. These contaminants include those regulated by the United States Environmental Protection Agency (USEPA) and Health Canada, as well as any other non-regulated compounds that may be of concern.
- What products are covered under NSF/ANSI Standard 61?
- Pipes and Related Products (including pipe, hose, fittings)
- Protective and Barrier Materials (including cements/coatings)
- Joining and Sealing Materials (including gaskets, adhesives, lubricants)
- Process Media (including carbon, sand, zeolite, ion exchange media)
- Mechanical Devices (including water meters, in-line valves, filters, process equipment)
- Mechanical Plumbing Devices (faucets, drinking fountains, and components)
- Potable Water Materials (non-metallic materials)
- What is involved in the NSF/ANSI Standard 61 Certification process?
The NSF Certification process has seven basic steps, as follows:
- Application - NSF/ANSI Standard 61 requires a disclosure by the manufacturer of all water contact materials in the product and a disclosure by the manufacturer's material suppliers of all chemical ingredients in the materials.
- Formulation, toxicology and product use information - Client and suppliers complete and submit NSF's Product Information Form. This provides formulation, toxicology and product use information.
- NSF formulation review - NSF toxicologists perform a formulation review for each water contact material to determine any possible ingredients, contaminants, or reaction by-products that may potentially leach from the material into drinking water. This formulation review then determines the battery of chemical analyses that will be performed on a particular material.
- Plant audit and sample collection - NSF then conducts an inspection of the production facility to verify the product formulation and production process and to ensure adequate quality control procedures are in place to prevent the use of unauthorized materials. Product samples are collected during the inspection and sent to NSF laboratories to be tested to the appropriate exposure protocol of NSF/ANSI Standard 61.
- Laboratory testing - Devices or materials are evaluated according to the exposure and analysis methods in Annex B of NSF/ANSI Standard 61. Most products undergo a 3-week exposure process where the products are exposed to various formulated waters designed to extract specific types of contaminants. Contaminant concentrations are determined from chemical analyses of the exposure water samples.
- Toxicology evaluation - These contaminant concentrations are then evaluated by a toxicologist to the pass/fail criteria in Annex D and E of NSF/ANSI Standard 61. Products that meet the requirements of the standard are then certified and appear in the NSF Listings. If products fail to meet the requirements of the standard, the manufacturer may identify the source of the failure and resubmit a reformulated product for certification.
- Certification granted
Follow-up program - Once products are certified and listed by NSF they are inspected and reviewed on an annual basis.
Listed production facilities are then subjected to unannounced annual inspections by NSF auditors to ensure that certified products are made according to the authorized formulations and processes. Products are collected on a routine basis (typically once annually) for retesting.
Occasionally, certified products will fail an annual retest. When this happens, NSF immediately notifies the manufacturer. NSF requires the manufacturer to stop shipment of noncompliant product and to fully investigate the cause of the failure. An NSF field auditor inspects the facility to ensure the manufacturer has taken these steps. If the manufacturer is able to identify and correct the cause of the failure, they may resubmit the product for certification. If the reformulated product meets the requirements of NSF/ANSI Standard 61, the manufacturer may again mark and sell the products as NSF certified.
- How was NSF/ANSI Standard 61 developed? How is it maintained?
NSF/ANSI Standard 61 is overseen by the NSF Drinking Water Additives Joint Committee. This committee has a balance of 1/3 public health regulatory members, 1/3 product manufacturer members, and 1/3 product user representatives. Any proposal to revise the standard is typically assigned to a task group composed of joint committee members and external experts. Task group members are assigned by the chairman of the joint committee.
One standing group is the Health Advisory Board. This group consists of toxicologists from USEPA, Health Canada, state and provincial agencies, as well as toxicologists from industry, and private consulting firms. This group is responsible for reviewing and approving all allowable contaminant concentrations that are published in NSF/ANSI Standard 61.
Any revision that is proposed by a task group must receive majority approval from the joint committee. Any negative ballots from the joint committee must be circulated to all committee members and adjudicated, according to the guidelines of the American National Standards Institute (ANSI).
Once a revision is approved by the joint committee, the proposal passes to the NSF Council of Public Health Consultants, which consists of regulatory officials from public health agencies across North America.
Revisions to NSF/ANSI Standard 61 are also circulated for public comment and any concerns addressed through the guidelines of the American National Standards Institute. ANSI gives final approval to each revision of the standard.
Anyone may submit a proposed change to the standard, as well as other issues for discussion by the joint committee, by submitting an issue paper to the chairman of the joint committee. All meetings of the joint committee are open and may be attended by requesting an invitation from the secretary of the joint committee. Contact standards@nsf.org for further information.
If you have additional questions relating to NSF/ANSI Standard 61, or NSF's certification services, contact Dave Purkiss at 734.827.6855 or purkiss@nsf.org.
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Processed and Fabricated Products
- Do certified products retain their NSF 61 certification if they are processed or fabricated and resold?
Many companies purchase NSF 61 certified products which are then reprocessed in some manner and resold. These processed or fabricated products do not retain their NSF Certification to NSF 61 unless the facility has an official NSF 61 Listing for the processed or fabricated product.
Example: Fabricated Pipe
A fabrication facility may purchase NSF 61 certified ductile iron pipe and fabricate grooved or flanged pipe and resell the product to a contractor or water utility. The product only retains the NSF 61 Certification if the fabrication facility has a NSF 61 listing for the grooved or flanged pipe. The certification denotes that the fabrication facility is inspected annually and has products periodically retested to confirm the fact that it is using NSF 61 certified pipe, that it has controlled sources of materials used for fittings and welding, and also ensure that any additional coating materials or processing aids are not going to add harmful contaminants to drinking water.
Example: Regenerated and reactivated media
Several process media companies now offer to take spent media from a water utility and regenerate or reactivate the media and then resell it to the water utility at a much lower cost than virgin media. How does the utility know that the media it is receiving back is the same media that they originally sent to the regeneration facility? How can the water utility be assured that the regenerated media conforms to NSF 61 and will not add harmful contaminants to drinking water? NSF 61 contains specific requirements for products and facilities that regenerate and reactivate media. Regenerated or reactivated media is not NSF 61 Certified unless the regeneration or reactivation facility has a NSF 61 Listing for the products.
Example: Repackaged process media
The same rule would apply to companies that are simply repackaging process media or other products. Even if a company is repackaging NSF 61 certified activated carbon, the NSF 61 certification is not maintained if it has not been separately certified for the repackaging company. How can a utility be sure that a company is only repackaging NSF 61 media and not substituting or mixing with some lower cost material that is not certified? Contamination control is another concern addressed by third party certification. If the repackaging facility has been separately certified then the water utility can be reassured that the facility is receiving unannounced annual inspections from NSF to verify the sources and certification of the media that is being packaged.
While a reprocessed or fabricated NSF 61 certified product does not retain its certification, it is still beneficial for manufacturers to choose NSF 61 certified materials for their end product. Choosing NSF 61 certified components or materials will save your company time and expenses when undergoing certification for your product.
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NSF/ANSI Standard 61 and Lead
- What are the requirements for NSF/ANSI Standard 61 and lead?
NSF/ANSI Standard 61 requires all metallic products and components to be evaluated for the leaching of lead as well as other metal contaminants. Annex G of NSF 61 contains an optional lead content verification method. Metallic pipe, fittings, valves, and other mechanical devices are all tested with two specially formulated waters. One is pH 5 and another pH 10. The pH 5 test water is especially aggressive for copper, chromium, nickel, and antimony. The pH 10 test water is especially aggressive for lead, arsenic, barium, beryllium, boron, cadmium, mercury, selenium, and thallium. Products are exposed to these test waters for 16 days where the device is filled with fresh test water each day. On the 17th day water is held in the device for 16 hours. The resulting contaminant concentrations are analyzed and mathematically normalized to reflect the concentrations expected from actual product when it is installed in the field. These normalized concentrations are then compared to the pass/fail results of NSF/ANSI Standard 61, which is 15 ppb for lead. This pass/fail criteria of 15 ppb is scheduled to be reduced to 5 ppb per Annex F of NSF 61.
Faucets, drinking fountains, and endpoint devices that dispense drinking water are tested and evaluated in a different manner. NSF/ANSI Standard 61 requires that these products be tested over a 19 day time period using a specially formulated pH 8 test water. Samples for lead are taken at 9 sample days throughout the 19 day test. Other metal contaminants are measured on the last day of the test. A minimum of 3 devices must be tested for lead and a statistical calculation is made based on the geometric mean of the lead leach concentrations, the standard deviation of the concentrations and a probability factor which is based on the number of products tested. A statistical Q value is derived from this calculation to represent the lead dose of the product. An endpoint device must have a Q value less than or equal to 11 ug of lead to meet the requirements of the standard. The Q value of 11 ug is scheduled to be reduced to 5 ug for endpoint devices and 3 ug for stop valves and flexible connectors per Annex F of NSF 61.
- Does NSF/ANSI Standard 61 only test for lead?
No, NSF tests for other metallic contaminants as well as nonmetallic contaminants. In fact, the standard requires a full formulation disclosure of all chemical ingredients in each water contact material. The standard then requires testing for any chemical contaminant that might possibly leach from each material into drinking water.
- Can a pure lead device pass NSF/ANSI Standard 61?
No. This misconception started when an article reported that a small lead device was tested to the NSF/ANSI Standard 61 test protocol and it passed for lead. A close reading of the article shows that the lead device was only tested with the pH 5 test water. It was not tested with the pH 10 test water, which is required by the standard. The same article claims that other devices were tested with both the pH 5 and pH 10 test waters and showed that the pH 10 test water was 71 times more aggressive for lead leaching than the pH 5 test water. If the factor of 71 was applied to the pH 5 test results for the small lead device, it would have clearly failed to meet the standard. In fact, many brass products containing only small amounts of lead have difficulty meeting the testing requirements of NSF/ANSI Standard 61.
- Has NSF/ANSI Standard 61 reduced the amount of lead in plumbing products?
The U.S. Safe Drinking Water Act of 1986 restricted the lead content in plumbing products to less than 8 percent. A recent survey of products submitted to NSF for evaluation under Standard 61 shows that 89 percent of all metal parts in valves and water meters contain less than 3.7 percent lead, and two-thirds contain less than 0.5 percent lead. We attribute this consistently decreasing amount of lead in new plumbing products over the past two decades to manufacturers' needs to receive NSF/ANSI 61 Certification and a sign of NSF/ANSI Standard 61's impact on protecting public health from lead exposure from drinking water. In addition Annex G of NSF 61 contains an optional evaluation method for weighted average lead content of <0.25% which is now required in some states.
If you have additional questions relating to NSF/ANSI Standard 61, or NSF's certification services, contact Dave Purkiss at 734.827.6855 or purkiss@nsf.org.
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USEPA FAQ on Lead in Plumbing Products
Note: This list of questions and answers was developed by the USEPA in 1997 to describe the requirements of the U.S. Safe Drinking Water Act revisions of 1996 and how they impact requirements for lead content, lead leaching and NSF/ANSI Standard 61, Section 9.
- Is there any law or regulation for lead in drinking water?
Yes. The National Primary Drinking Water Regulations (NPDWR) for Lead and Copper, 40 CFR Parts 141 and 142, promulgated in 1991, established an action level of 15 parts per billion (ppb) for lead in drinking water. Action level exceedance is determined by measuring the concentration of lead in a number of samples collected from a specified number of consumer's taps. The lead action level is exceeded if the concentration of lead in more than 10 percent of tap water samples is greater than 15ppb. Public water systems exceeding the lead action level are triggered into treatment technique requirements including corrosion control treatment, public education, and, if appropriate, source water treatment and/or lead service line replacement.
- What are the sources of lead in drinking water?
Lead in drinking water results primarily from corrosion of materials containing lead installed in building plumbing such as lead solder, brass, bronze and other alloys containing lead in contact with the water. The amount of lead attributable to corrosion by-products in the water depends on a number of factors, including the amount and age of lead bearing materials susceptible to corrosion, the way they were manufactured, how long the water is in contact with the lead-containing surfaces, and how corrosive the water is towards these materials. The corrosivity of water is influenced by a number of factors, including acidity, alkalinity, dissolved solids and hardness. In general, soft acidic waters are more corrosive to lead than hard waters.
- Is there any law or regulation limiting lead content in pipe, plumbing fittings, fixtures, faucets, solder and flux?
Yes. Section 1417(a)(1) of the Safe Drinking Water Act (SDWA) requires that after June 19, 1986 only "lead free" pipe, solder or flux may be used in the installation or repair of (1) Public Water Systems, or (2) any plumbing in a residential or non-residential facility providing water for human consumption, which is connected to a Public Water System. Under section 1417(d), "lead free" as defined in the SDWA means that solders and flux may not contain more than 0.2 percent lead, and pipes, pipe fittings,and well pumps may not contain more than 8.0 percent lead.
- How can I tell if a faucet or plumbing device contains more than 8% lead?
In general, plumbing products that are on the market contain 8% or less lead. The amount of lead contained in the plumbing product is usually governed by its manufacturing process. In order to find out how much lead is contained in a plumbing product, you should contact the manufacturer or the importer/distributor and ask for a certificate of lead content.
Another approach is to send the plumbing product to a laboratory and have it analyzed for lead content. However this approach may not be practical since the cost of the test could be several times of the purchase price the product.
- Can "lead-free" plumbing fixtures or devices leach lead?
Yes, as noted in response to Question 2, any plumbing device or fixture that contains lead and is in contact with the water is a potential source of contamination. Brass fittings and plumbing fixtures, containing 8% or less lead, have been found to contribute high lead levels for a considerable period of time after their installation, even in cases where these devices are in contact with relatively non-corrosive waters. The amount of lead that may leach into the water from a brass faucet or fixture is not solely related to the amount of lead contained in the alloy. The amount of lead leaching from a brass alloy is greatly influenced by the manufacturing process.
- Is there a performance standard limiting the leaching of lead into drinking water from faucets, fittings, fixtures, pipes, and plumbing devices?
A voluntary standard, NSF International's consensus Standard 61,(NSF/ANSI Standard 61: Drinking water System Components-Health Effects), including inline and endpoint devices has been established. The criteria for lead in the NSF Standard limits the amount of lead that can leach into the water from a particular product. The standard does not specify the lead content in that product. Devices that are made of brass alloys that contain lead may be certified if they pass the performance test prescribed by the standard. Some manufacturers modified their manufacturing processes to meet the NSF Standard.
NSF Standard 61, section 9 covers endpoint devices. The NSF Standard defines endpoint devices as mechanical plumbing devices, components, and materials which are typically installed within the last liter of the distribution system and are intended by the manufacturer to dispense water for human ingestion. The devices include kitchen and bar faucets, lavatory faucets, water dispensers, drinking fountains, water coolers, glass fillers, residential refrigerator ice makers, supply stops, and endpoint control valves.
NSF Standard 61, section 8 covers mechanical devices which include inline devices in building distribution systems, including any device that is used to measure or control the flow of water that is used in treatment/transmission distribution systems and is in contact with the water intended for human ingestion. Inline devices in a building used to measure or control the flow of water include water meters, building valves, check valves, meter stops, valves and fittings backflow preventers, etc. The NSF Standard defines inline devices as any device installed on a service line or building distribution system downstream of the water main and before endpoint devices.
NSF Standard 61, Section 4 covers pipes, fittings and small drinking water storage devices having domestic or residential applications including the products or water contact materials of: pipes, fittings, tubing, hoses, well casing, drop pipes and screens etc.
- How does NSF Standard 61, Section 9 relate to the definition of lead free?
NSF Standard 61, Section 9 relates to the amount of lead leached from a product while the definition of "lead free" for pipe and pipe fitting corresponds to a maximum of 8% lead content. By amending Section 1417 of the SDWA, Congress incorporated a performance standard into the law for endpoint devices intended to "dispense water for human consumption." Section 1417(e) of the SDWA, states that "lead free" with regard to plumbing fittings and fixtures intended to dispense water for human consumption means those fittings and fixtures that are in compliance with a voluntary standard established pursuant to the Act. The reason for this requirement by Congress, EPA believes, was that some brass fittings and plumbing fixtures containing 8% or less lead have been found to contribute high lead levels for a considerable period of time after their installation, even in contact with relatively non-corrosive waters. Because of low flow and infrequent usage, lead concentration levels in water in contact with endpoint devices dispensing water for human consumption were found in some cases, to exceed the 15 ppb action level for lead, established by EPA in the Lead and Copper Rule.
- Can an endpoint plumbing device meeting the 8 percent limitation specified by the SDWA, but not meeting an approved voluntary standard, such as the NSF Standard 61, Section 9, be used in the installation or repair of Public Water Supply Systems?
No. In order to be legally used in the installation or repair of public water supply systems, after the statutory deadlines, a product must be certified by an approved voluntary standard and meet the 8% "lead free criteria."
- How much lead does the NSF Standard allow to be leached from endpoint devices?
The NSF Standard limits the amount of lead from endpoint devices to 11ppb when normalized to 1 liter. This approach is based on the 15ppb action level established in the lead and copper rule, considering the 11ppb lead contributed from the endpoint device as well as from sources other than the endpoint device, which is assumed to be 4ppb. [Note: The value of 11 ug is scheduled to be reduced to 5 ug for endpoint devices and 3 ug for stop valves and flexible connectors per Annex F of NSF 61.]
- What is the NSF test procedure for endpoint devices?
The NSF test procedure requires that at least three endpoint devices be exposed to specially formulated water for a period of 19 days. On days 3, 4, 5, 10, 11, 12, 17, 18, and 19, water samples from the endpoint devices are collected. The observed lead dosage levels, (lead concentration times the volume of the endpoint device) normalized to 1 liter are determined and statistically compared to the 11ppb limit.
- Are inline devices regulated under the SDWA? Does the SDWA require inline devices to meet health effects based performance standards?
The SDWA prohibits the use of any pipe, any plumbing fitting or fixture that is not lead-free (containing more than 8% lead) in the installation or repair of any public water system or any plumbing in residential or non-residential facility providing water for human consumption, which is connected to a public water supply system.
However, there is no specific language in the SDWA which would require that inline devices meet health effects-based performance standards limiting the leaching of lead into the drinking water. Therefore, EPA has not recognized these standards as requirements for purposes of Section 1417 of the SDWA. Thus, while EPA encourages the industry to conform with these standards, the industry is not currently required to do so. However the absence of explicit statutory requirements that such devices comply with NSF Standard 61 does not preclude state or local governments from adopting such requirements.
In most instances, inline devices installed in building plumbing systems handle a large volume of water used for showering, laundry, etc. compared to endpoint devices dispensing water for human consumption. Although some inline devices containing 8% or less lead may leach certain quantities of lead, the amount of lead leached from these devices would generally be expected to be diluted to levels below those of concern by the relatively high volume of water passing through them.
- How can I be sure that the faucet or plumbing device meets the NSF Standard?
Products certified against the NSF Standard carry a certification mark of the certifying organization. NSF International publishes listing books of products that it has tested and certified against the NSF Standard. NSF International also maintains these listings through its Internet site. One can obtain Listing books from NSF International at 1-800-NSF-MARK (800-673-6275), or visit its website at www.nsf.org.
- Which parties helped develop the NSF Standard?
The standard was developed using voluntary consensus process. All interested parties were represented, including regulatory agencies, industry, water suppliers, consultants, and other users of products covered by the standard.
- Is NSF the only organization that can test against the Standard?
Any organization that is accredited by the American National Standards Institute to certify products against NSF Standard 61 can test products against the NSF Standard. Currently 44 states have regulations requiring products to meet NSF Standard 61 and all of these states require products to be certified by an ANSI-accredited certifier.
- What is the deadline for selling non lead-free products?
The law prohibits any person from introducing into commerce any pipe, or plumbing fitting or fixture that is not lead free after August 6, 1998, except for a pipe that is used in manufacturing or industrial processing.
The law does not make any distinction between the wholesale and retail sales of these materials. Thus, the sale or distribution from inventory of any pipe, or any pipe or plumbing fitting or fixture, that is not lead free, is prohibited after the deadline established by the SDWA.
- Does the exception for industrial and manufacturing processes apply to all such uses?
The exception applies to any process where the water conveyed by the plumbing or distribution system is not used directly or indirectly for human consumption.
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Standard 61, Annex F (2007a)
NSF/ANSI Standard 61 was revised in August 2007 to change the evaluation criteria for lead in drinking water products. These changes are reflected in Annex F of the standard. For questions or concerns regarding this change, please contact Pete Greiner at 734.769.5517 or greinerp@nsf.org.
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Standard 61, Annex G (2008)
Questions on NSF-61 Annex G, plus the latest information on the low lead in plumbing products issue, can be found on the NSF Low Lead Plumbing Products website.
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Stainless Steel Products and NSF Standard 61
- What is stainless steel?
Stainless steel, compared to typical steel, is a general class of metal alloys that contains lower levels of iron and higher levels of chromium, vanadium, etc. The actual percent of the various elements yield different physical properties.
- Why do people use stainless steel products with drinking water systems?
In general, stainless steels are quite hard, tough, and corrosion resistant in comparison to some other materials used in drinking water applications.
- Are all stainless steel products compliant with NSF Standard 61.
No. Only products that are certified to NSF/ANSI Standard 61 can be assumed to meet the requirements of NSF/ANSI Standard 61. Certification to NSF/ANSI Standard 61 includes product testing and production location auditing to ensure ongoing compliance with the health based requirements of NSF 61. This includes testing products on an annual basis, by exposing them to different formulated waters (typically at pH 5, pH 8 and pH 10) and testing for regulated metals such as antimony, arsenic, barium, cadmium, chromium (including chromium VI), copper, lead, mercury, selenium, thallium, and nickel, as well as any other inorganic and organic leachate concerns that may derive from cutting oils, lubricants, process aids, welding, machining, and other forming by-products. The certification process also includes annual unannounced inspections of the manufacturing facility to verify that the manufacturer is making the product using the same raw materials, material suppliers and production process as the products that are tested.
- I thought because stainless steel was listed in Annex C of NSF 61 that all stainless products meet the requirements of the standard?
Annex C of NSF 61 provides a list of materials that have been extensively tested under certain conditions, which then can reduce the amount of testing that NSF needs to perform when certifying products to NSF 61. For example several grades of stainless steel have been listed under Annex C at specific surface area to volume ratios and at certain temperatures (23°C and 30°C). When product manufacturers use these materials in their products under these conditions, NSF may not have to do as much testing as we would if they were using other materials. However NSF would still need to audit the manufacturing facility to verify that these materials are being used in certified products, and testing would be required if other materials are in the products, or if the stainless steel is being used at higher temperatures such as domestic (60°C) or commercial (82°C) hot water.
- I need NSF Standard 61 Certified stainless steel pipe and fittings. Where do I find them?
Use the NSF web-based Standard 61 Certified Potable Water System search engine.
From the NSF website you may choose from many search criteria such as:
- Manufacturer name, if you know the maker of the product
- Product trade name, if you know the tradename or model number, etc.
- Manufacturing location, if you seek product from a certain country, state, etc.
- Product type, if you need a particular item like pipe, valve, fitting, pump, etc.
- Material type, if you need a specific material such as SS, PVC, PE, Cu, brass, etc.
- If I can't find the specific company/product type I seek, what should I do?
Contact NSF staff for assistance. Have details of your target products and preferred suppliers. NSF staff may be able to help you find the NSF 61 Certified products you seek. NSF can also help you by networking with your preferred suppliers and rapidly arranging the appropriate evaluation of products you need to meet bid specifications and drinking water safety requirements.
- Why do companies get NSF Standard 61 Certified for stainless steel products?
Most US States and Canadian Provinces have regulations or policies that require public drinking water system components to comply or be certified to NSF Standard 61. In addition most of the plumbing codes across the US also require products to be certified to NSF 61. While enforcement of these requirements varies greatly by region, these requirements have resulted in a growing number of specifications for NSF 61 for stainless steel and other potable water products.
Make sure the products you buy are NSF Certified!
If you have additional questions relating to NSF/ANSI Standard 61 and stainless steel or NSF's certification services, contact Dave Purkiss at 734-827-6855 or purkiss@nsf.org.
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