DC-900500-1.9, Duracast 500 Gallon Heavy Duty Vertical Tank | 900500 These heavy duty storage tanks have excellent mechanical properties, a seamless design and a high resistance to environmental stress. These important traits makes Duracast’s vertical storage tanks your ultimate storage solution for corrosive chemicals or any liquid up to 1.9 specific gravity. These tanks will not break down from harsh UV rays because the resin is made with UV stabilizers. The resin is also FDA approved, which makes these tanks a safe storage container for potable water. These tanks are equipped with convenient features including an 16-inch vented manway fitting and measurement graduations molded into the tanks. Choose from green, black or natural white tanks. This is a 1.9 specific gravity tank.