NALA Membranes makes reverse osmosis membranes that hold up to chlorine, so water treatment plants can use chlorine to stop bacteria clogging them.

Reverse osmosis has used the same polyamide membranes for more than forty years, and chlorine breaks them down. NALA's are made from a different material, a patented sulfonated polysulfone layer, which the company says survives chlorine about 1,245 times as long as the standard membrane. It drops into existing systems.

Membranes that survive chlorine need less cleaning and last longer; NALA puts the saving at 24% of a system's operating costs. Judy Riffle, the polymer chemist who invented the material, founded the company in North Carolina in 2018 with Sue Mecham, now its CEO. In 2025 it signed a multi-year agreement to supply membranes to wastewater company Concord Enviro Systems.