California – Iowa – Wisconsin

Due to strict state-level regulations, Berkey is unable to sell its systems in California, Iowa, and Wisconsin, where laws place heavy restrictions on residential water filtration products that make health-related claims. In these states, any system marketed as reducing contaminants that affect human health must undergo independent third-party testing and certification—typically under recognized standards such as NSF/ANSI—and must also be properly registered and approved at the state level. Regulations in California are particularly stringent, requiring ongoing compliance, detailed performance data, and accurate labeling before a product can be legally sold. Iowa and Wisconsin enforce similar rules, especially for systems that rely on post-carbon filtration and advertise broad contaminant reduction claims. Because these requirements are more rigorous than in most other states, companies that have not completed the full certification and regulatory approval process are restricted from selling their products there, even if those same systems are available throughout the rest of the country.