; or (III) an acute risk hazard quotient that is greater than 1; and (C) is— (i) classified in one or more of North American Industry Classification System codes 322, 324, 325; or (ii) required to prepare and implement a risk management plan pursuant to section 112(r) of the Clean Air Act ( 42 U.S.C. 7412(r) ) and had an accidental release required to be reported during the previous 3 years pursuant to section 68.42 or 68.195 of title 40 Code of Federal Regulations (as in effect on the date of enactment of this Act). (3) Pollutants The pollutants described in this paragraph are ethylene oxide, chloroprene, benzene, 1,3-butadiene, and formaldehyde. (d) Methods and technologies (1) In general Except as provided in paragraph (2), in carrying out the program under subsection (a), the Administrator shall— (A) for each stationary source on the list developed under subsection (c)(1), employ, as necessary to monitor the pollutants described in subsection (c)(3) emitted by such stationary source, at least— (i) Method 325A and Method 325B; and (ii) Method TO–15; and (B) for each of the 10 stationary sources on such list that either emit the greatest volume of pollutants described in subsection (c)(3), or cause the greatest health risk as determined by the Administrator based on a residual risk assessment performed pursuant to section 112(f)(2) of the Clean Air Act ( 42 U.S.C. 7412(f)(2) ) or based on the most recent National Air Toxics Assessment due to such emissions individually, as a group, or cumulatively with all hazardous air pollutants emitted by such sources, and for any other stationary source on such list for which application of the methods described in subparagraph (A) alone will not be sufficient to monitor and report any such pollutants that are emitted by such stationary source, employ— (i) optical remote sensing technology to provide real-time measurements of air pollutant concentrations along an open-path