About100 workers in a gas processing plant are exposed to the following concentrations of phosgene gas for the indicated hours.

a. 2.2 ppm for 2.75 hr

b. 1.5 ppm for 3.00 hr c

. 0.1 ppm for 2.25 hr

To determine the potential fatalities, there are two approaches to interpret the problem: (i) assume the same workers exposed over 8-hr (2.75 + 3.00 + 2.25) period, and (ii) assume each exposure is separate (i.e., independent and isolated event) with different workers.

Using the Probit Eqn, 2-5 (Textbook): , where C in ppm and T in min with k₁ = -19.27 and k₂ = 3.69, determine the potential fatalities by the two methods as articulated above (i & ii). Briefly, interpret your results obtained by the two methods.

= k + kyln() c )