Although a variety of acid-generating molecules have been developed, the formation of toxic byproducts and the need for light-activation or temperatures that may be incompatible with physiological conditions leave room for the optimization of biocompatible acid-generators. Herein, we report 4-hydroxybenzyl chloride derivatives that generate hydrochloric acid via hydrolysis at the benzylic position at room temperature in the absence of light. Utilizing the acetal protected 4-hydroxybenzyl chloride scaffold, we access a myriad of compounds that generate acid at different rates.