(a) A smoke alarm must be:
(1) designed to detect both the visible and invisible products of combustion;
(2) designed with an alarm audible to a person in the bedrooms it serves; and
(3) tested and listed for use as a smoke alarm by Underwriters Laboratories, Inc., Factory Mutual Research Corporation, or United States Testing Company, Inc.
(a-1) If requested by a tenant as an accommodation for a person with a hearing-impairment disability or as required by law as a reasonable accommodation for a person with a hearing-impairment disability, a smoke alarm must, in addition to complying with Subsection (a), be capable of alerting a hearing-impaired person in the bedrooms it serves.
(b) Except as provided by Section 92.255(b), a smoke alarm may be powered by battery, alternating current, or other power source as required by local ordinance. The power system and installation procedure of a security device that is electrically operated rather than battery operated must comply with applicable local ordinances.