What Are the National Sanitation Foundation (NSF) Drinking Water Certifications?
What is NSF Certification?
Millions of people take the safety of their food, water and consumer products for granted on a daily basis. Why? Because of three letters: NSF. NSF certification is the key to making sure that the products we use meet strict standards for public health protection.
Choosing a product certified by NSF lets you know the company complies with strict standards and procedures imposed by NSF. From extensive product testing and material analyses to unannounced plant inspections, every aspect of a product's development is thoroughly evaluated before it can earn the NSF certification.
NSF certification is not a one-time event but involves regular on-site inspections of manufacturing facilities and regular retesting of products to ensure that they continue to meet the same high standards required to maintain certification over time. If for any reason a product fails to meet one or more certification criteria, NSF will take enforcement actions to protect consumers, including product recall, public notification or decertification.
Products that earn NSF certification are said to be “NSF certified” or “NSF listed” and display the applicable NSF certification mark to show that they have been tested by one of today’s most respected independent product testing organizations.
What are the Primary NSF Certifications for Drinking Water?
NSF/ANSI 42 Standard refers to filters that are certified to reduce aesthetic impurities such as chlorine and taste/odor/appearance (e.g. chlorine, chloramine, particulate matter, etc). These can be point-of-use (under the sink, water pitcher, etc.) or point-of-entry (whole house) treatment systems.
NSF/ANSI 53 Standard refers to filters are certified to reduce a contaminant with a health effect when ingested (e.g. asbestos, lead, arsenic, PFOAs, microcystin, etc). Health effects are set in this standard as regulated by the U.S. Environmental Protection Agency (EPA) and Health Canada. Both standards 42 and 53 cover adsorption/filtration which is a process that occurs when liquid, gas or dissolved/suspended matter adheres to the surface of, or in the pores of, an adsorbent media. Carbon filters are an example of this type of product.
NSF/ANSI 55 Standard: This certification pertains to ultraviolet (UV) treatment systems. UV systems disinfect water by exposing it to UV light, which effectively inactivates bacteria, viruses, and other pathogens without the use of chemicals. NSF/ANSI 55 ensures that these systems meet specific performance criteria for UV dosage and safety, providing assurance that they can reliably disinfect water to a safe level for consumption.
NSF/ANSI 58 Standard: This standard is specific to reverse osmosis (RO) systems. RO systems work by forcing water through a semi-permeable membrane, which effectively reduces a wide array of contaminants, including certain heavy metals like lead and arsenic, as well as fluoride and nitrates. These systems are particularly effective in areas where the water supply may have a high level of dissolved solids or other difficult-to-remove contaminants.
NSF/ANSI 244 Standard: This standard applies to point-of-use (POU) microbiological water purifiers. It certifies that these systems can effectively reduce or remove microbiological contaminants such as bacteria, viruses, and cysts from drinking water. This certification is particularly important for areas where waterborne pathogens are a concern.
NSF/ANSI 401 Standard refers to filters that are certified for emerging contaminants removal and include both point-of-use and point-of-entry systems that have been verified to reduce one or more of 15 emerging contaminants from drinking water (e.g. prescription drugs, over-the-counter drugs, microplastics, DEET, etc). These emerging contaminants can be pharmaceuticals or chemicals not yet regulated by the EPA or Health Canada whose long-term health effects are not yet fully determined.
NSF Protocol P231 refers to filters that are certified for the purification of microbiological contaminants (e.g. bacteria, viruses, live cysts, etc). These filters are certified for health and sanitation based on the recommendations of the EPA’s Task Force Report, Guide Standard and Protocol for Testing Microbiological Water Purifiers (1987) (Annex B).
What are the Secondary NSF Certifications Drinking Water?
NSF/ANSI 44 Standard: This standard applies to cation exchange water softeners, which are designed to treat hard water. Hard water contains high levels of minerals like calcium and magnesium, which can cause scaling in pipes, appliances and fixtures. Scaling not only damages plumbing but can also decrease the efficiency of appliances and affect the cleaning action of soaps and detergents. NSF/ANSI 44 certified softeners are tested to ensure they effectively reduce these minerals. The certification also evaluates the structural integrity of the softener, its effectiveness in reducing hardness and ensures it does not add harmful levels of sodium or other substances to the treated water.
NSF/ANSI 62 Standard: This standard is for distillation systems, which purify water by heating it to create steam, then condensing the steam back into liquid form. This process effectively removes a wide range of contaminants, including minerals, heavy metals, and some organic compounds. NSF/ANSI 62 ensures that distillation units meet specific requirements for contaminant reduction, material safety, and structural integrity. It's important for consumers looking for a high level of purification, particularly in areas where water contains a broad range of contaminants.
NSF/ANSI 177 Standard: This standard specifically addresses shower filters, which are not for drinking water but for reducing exposure to chlorine when showering. Chlorine, commonly used for water disinfection, can be absorbed through the skin and inhaled in the form of chloroform gas during hot showers. NSF/ANSI 177 certified shower filters are tested for their ability to reduce free chlorine, helping to minimize these exposures. This certification is particularly relevant for people with sensitive skin or respiratory issues.
NSF Protocol P231: This is a protocol for microbiological water purifiers, assessing their effectiveness in removing or inactivating bacteria, viruses, and cysts. Products meeting this protocol are tested under extreme conditions that simulate highly contaminated water. This certification is crucial for ensuring the safety of drinking water in emergency situations, outdoor activities, or in areas where the water supply is known to be compromised.
NSF P473 Standard: This certification focuses on the reduction of PFOA and PFOS, which are part of the larger group of PFAS chemicals. These substances are found in various consumer products and industrial applications and have been linked to health issues like cancer and hormone disruption. NSF P473 ensures that certified water treatment devices effectively reduce these specific contaminants to levels considered safe by public health standards.
NSF/ANSI/CAN 60: This standard applies to chemicals used in treating drinking water. It ensures that these chemicals are safe and do not introduce harmful levels of contaminants into the water. This includes evaluating the toxicity of the chemicals themselves and any potential byproducts that might be formed when they are used in water treatment processes. This certification is essential for ensuring the safety of chemicals used in municipal water treatment and other large-scale water purification systems.
NSF/ANSI/CAN 50: Though primarily focused on pools and spas, this standard is relevant for any equipment used in recreational water facilities, including filters. It covers a wide range of products, ensuring they meet health and safety standards. This includes evaluating the effectiveness of filters in reducing contaminants, the safety of materials in contact with water, and the structural integrity of the products. This certification helps to ensure a safe and healthy recreational water environment.
