SH&E professionals may be asked to determine secondhand smoke (SHS) exposures as a part of worker safety or exposure assessments. This article critically examines a recently proposed set of equations for predicting concentrations of SHS markers in air. It concludes that such models should not be employed until they are fully validated and asserts that use of measured, population-specific, SHS concentrations should remain the preferred practice in job safety assessment for this potential workplace hazard.