There is no single, universal “margin of error” for computed respirator cartridge change-out schedules. Because software calculators—such as NIOSH’s MultiVapor™ or manufacturer-specific tools like 3M™ Select and Service Life—rely on predictive mathematical models (most commonly Gerry Wood’s adsorption model), their accuracy depends entirely on how closely the inputted parameters match real-world workplace conditions.
In controlled laboratory studies evaluating mathematical models against actual experimental breakthrough times, the relative error for single organic vapors under steady-state conditions typically ranges between 9% and 15%. However, in active industrial environments, the real-world margin of error can deviate significantly due to environmental fluctuations, chemical interactions, and human factors.