NSF

An American food-safety and public-health certification body. NSF/ANSI 42 and 53 are the standards specifically for drinking-water filtration — 42 covers aesthetic effects (chlorine, taste, odour), 53 covers health-related contaminants.

Why it matters — When evaluating water filters for café or commercial use, NSF certification means the filter has been tested by an independent body — not just claimed by the manufacturer. Most commercial water filtration carries NSF.

Good to know

• Check the certification category — NSF 42 alone is much less rigorous than 42+53 combined.
• NSF and SCA (Specialty Coffee Association) water standards aren't the same thing. NSF covers safety; SCA covers brewing performance.