MONAQUAT TG has been found to be a good thickening agent for hydrochloric acid. MONAQUAT TG has been used to thicken 1% to 11% aqueous HCl. Viscosities of over 2000 cp. (Brookfield RUF-100 #7 spindle, 100 rpm. @ 25'C) have been achieved with the following stable information: HCl (37% A)/20.3 or 100.0 DI Water/63.0 MONAQUAT TG (30% A)/16.7