have installed not less than one carbon monoxide detector per floor of the dwelling unit in accordance with standards and criteria acceptable to the Secretary for the protection of occupants in the dwelling unit. . (c) Public housing Subsection (a) of section 3 of the United States Housing Act of 1937 ( 42 U.S.C. 1437a(a) ) is amended by adding at the end the following: (8) Carbon monoxide detectors (A) In general Each public housing agency shall ensure, for each dwelling unit in public housing owned or operated by the public housing agency, that not less than one carbon monoxide detector is installed per floor in the dwelling unit in accordance with standards and criteria acceptable to the Secretary for the protection of occupants in the dwelling unit. (B) Rehabilitation With respect to public housing for which a public housing agency is undergoing or planning a substantial rehabilitation project, the public housing agency shall ensure that, during that rehabilitation, not less than one carbon monoxide detector is installed per floor in each dwelling unit located in that public housing in accordance with standards and criteria acceptable to the Secretary for the protection of occupants in the dwelling unit. . (d) Section 8 housing Subsection (o) of section 8 ( 42 U.S.C. 1437f(o) ) is amended by adding at the end the following: (21) Carbon monoxide detectors (A) In general Each owner of a dwelling unit receiving tenant-based assistance or project-based assistance under this subsection shall ensure that not less than one carbon monoxide detector is installed per floor in the dwelling unit in accordance with standards and criteria acceptable to the Secretary for the protection of occupants in the dwelling unit. (B) Rehabilitation With respect to a property receiving tenant-based assistance or project-based assistance for which the owner is undergoing or planning a substantial rehabilitation project, the owner shall ensure that, during that rehabilitation, not less than one carbon monoxide detector is installed per