iSpring sediment filters are manufactured to comply strictly with FDA standard (CFR - Part 177) and tested by independent third party against NSF/ANSI standard for material safety and water quality. (NSF/ANSI 42, by NSF International, 10/2018)A combination of a sparse layer, compaction layer, and precision layer ensures this iSpring premium 5-micron polypropylene sediment filter captures dirt, sand, silt, dust, rust, and scale particles effectively. Combining with other filters such as CTO filter(FC15B), iSpring fine PP sediment filter not only brings clean and refreshing water to every faucet in your home but also helps to prolong the lives of your appliances and protects plumbing from sediment and scale buildup. With affordable pricing, solid quality, prompt delivery, and top notch customer service, we hope to assist in bringing you great water for years to come.