Liquid caustic ingestions: an in vitro study of the effects of buffer, neutralization, and dilution

Changes in pH and temperature of solutions of common commercial liquid caustics were determined in vitro following the addition of neutralizing agent, buffer, and diluent. Neutralization of strong base was complete following the addition of less than twice the volume of weak acid with only a minimal release of heat. Buffer added to a strong acid caused an immediate temperature elevation without changing the pH; a gradual rise in pH followed. Large volumes of diluent caused little change in temperature or pH of either strong base or strong acid. We conclude that dilution as a first-aid measure is ineffective, whereas buffer is ineffective and possibly harmful. Neutralization is effective in reversing pH change, but in vivo studies are needed to confirm the relative roles of pH extremes and heat in the genesis of tissue injury.