Muriatic acid is diluted Hydrochloric acid (HCl) at a concentration of 31.45% or less.
Pure Hydrochloric acid (HCl) is used in primarily laboratories and industrial applications, not swimming pools and spas. This has to do with the dangers of handling and transportation. While muriatic acid is the same chemical compound as HCl, it is diluted with water down to 31.45% or less.
31.45% is the most common concentration on the market, but there are also 20% and 25% variations that can be purchased in pool stores and hardware stores. Anything at or below 31.45% HCl is considered muriatic acid.
HASA Muriatic Acid options
Hydrochloric acid is produced as a byproduct of producing liquid chlorine. It's called the chlor-alkali manufacturing process. HASA offers muriatic acid in two concentrations:
- Acid-15® (15% HCl) - [PDF of product SDS]
- Muriatic acid (31.45% HCl) - [PDF of product SDS]