Personal Protective Equipment Test No. 5 From IFSTA Hazmat for First Responders 4th Edition Progress Indicator: Question 1 of 15 1.  Which type of SCBA is allowed to be used at incidents where responders are exposed to hazardous materials? p. 384 Choices: Pressure-demand open-circuit Pressure-relayed open-circuit Positive-pressure open-circuit Negative-pressure open-circuit