Md. Code, Public Safety § 9–106.1

(a) This section does not apply to:

(1) a fire alarm, a smoke detector, a smoke alarm, or an ancillary component that is:

(i) electronically connected as a part of a listed centrally monitored or supervised alarm system; or

(ii) capable of sending and receiving notifications by:

1. a low–power radio frequency wireless communication signal; or

2. a wireless local area networking capability; or

(2) any other device that the State Fire Marshal designates as exempt through the regulatory process.

(b) On or after October 1, 2018, a person may not sell a battery operated smoke alarm in the State for compliance with this subtitle unless the smoke alarm is a sealed, tamper resistant unit incorporating a silence/hush button and using one or more long–life batteries.