“…The general detection threshold was estimated by equation 1, where the independent variable is the logarithm concentration of The value of the general detection threshold calculated by equation 1 (0.0041 g/L − FeSO 4 .7H 2 O) was obtained from the subjects evaluated by this study. It is different, in absolute value, from data which are presented by other authors (Shiffman, 2000;Zacarias et al, 2001;Gonzalez et al, 1998;Lim and Lawless, 2005a;Lim and Lawless, 2006;Epke and Lawless, 2007). However, approximated to that indicated by ISO (1991), which indicate the concentration of 0.00475 g/L, which is perceptible.…”