Potable water reservoir coatings

Potable water reservoirs — residential/commercial water tanks, elevated reservoirs, underground distribution tanks, cisterns of large buildings — require specific internal coating that guarantees potability of the stored water. Coatings must be fully inert (not releasing substances into water), durable (decades of continuous water contact), washable and sanitizable (periodic cleaning with specific products), resistant to thermal variations and reservoir structural movements. Traditionally dominated by food-grade epoxy coatings, aliphatic PU grows in specific segments due to combination of superior flexibility (accommodates structural movements without cracking), UV resistance (in sun-exposed metal reservoirs), and ease of spray application in complex geometries. Global reference standards: NSF/ANSI 61 (USA/Canada) is gold standard; ABNT NBR 5626, ANVISA and Portaria MS 888/2021 in Brazil. Significant market driven by hydraulic infrastructure expansion in emerging markets and aging infrastructure maintenance in developed markets.