Endogenous Respiration Rate Constant is usually measured using the 1 Per Day[d⁻¹] for First Order Reaction Rate Constant. 1 Per Second[d⁻¹], 1 Per Millisecond[d⁻¹], 1 Per Hour[d⁻¹] are the few other units in which Endogenous Respiration Rate Constant can be measured.