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Keyword: detector

BCoFD has heard from many residents with questions about Maryland's new smoke alarm law, which was signed in 2013 but includes some requirements that just took effect on January 1, 2018. This fact sheet is designed to clarify this regulation and what it means for you.

What the law requires now

  • Replacement of battery-only smoke alarms with new, 10-year smoke alarms with sealed batteries and a "hush" feature (to silence the alarm temporarily during cooking).
  • Replacement of hardwired devices more than 10 years old. Hardwired devices newer than 10 years still are acceptable.
  • Hard-wired devices must be replaced with hard-wired devices. You cannot replace a hard-wired alarm with a battery-only alarm.

What the law requires in the future

  • The law requires replacement of ALL smoke alarms -- hard-wired and battery-only -- when they are 10 years old. That means 10 years from the date of manufacture printed on on the back of the alarm. If you can't find a date, your smoke alarm needs to be replaced.
  • Smoke alarms lose their operational sensitivity after 10 years.
  • Hard-wired devices must be replaced with hard-wired devices.

What brand of alarm should I buy?

  • BCoFD does not endorse one manufacturer over another.
  • Smoke alarms are available at most home supply and "big box" retail stores and at many online retailers.
  • Alarms should comply with Underwriters Laboratory (UL) 217, "Standard for Safety for Single and Multiple Station Smoke Alarm."

What about rental properties?

  • The new law applies to rental properties.
  • However, the new requirements do not impact individuals in the County’s rental registration program because the County’s rental registration provisions do not permit battery-operated smoke detector units and require hard-wired smoke detectors.


  • The local fire code does not grant right of entry into privately-owned single- and multi-family dwellings.

Purpose of the law

  • The law was designed to achieve the most reliable smoke alarm coverage possible in older dwellings without requiring homeowners to run new wiring.
  • The law's overall purpose is reduction of fire deaths and injuries.
  • Studies of residential fire fatalities show that more than half of smoke alarms in these incidents failed to sound because the 9-volt battery had been removed. The sealed battery requirement eliminates that problem.

Placement of smoke alarms   Smoke alarm location

A new state law regarding battery-powered smoke alarms and designed to reduce home fire deaths became effective January 1, 2018.

This law requires replacement of all smoke alarms (hard-wired and battery-only) when they are 10 years old. It also requires the replacement of all battery-powered smoke alarms with new, 10-year alarms with sealed-in batteries and a "hush" button feature.

Do not remove hard-wired smoke alarms and replace them with battery-operated smoke alarms of any kind. A 110-volt electrically powered smoke alarm may be replaced only with a new, 110-volt unit with battery backup.

The change also applies to properties in the County's rental registration program required by County law to have hard-wired smoke alarms.

Making Smoke Alarms Tamper Resistant

The change in law is designed to make smoke alarms tamper resistant. According to the Maryland State Fire Marshal, two-thirds of home fire deaths across the U.S. occur in homes that either do not have smoke alarms or that do not have working smoke alarms -- usually because the batteries have been removed. Sealing the battery inside the alarm means consumers do not have to remember to change the batteries and cannot remove them for other uses. Sealed-in, continuous use smoke alarms provide life-saving protection for a decade.

The new Maryland Smoke Alarm Law requires replacement of smoke alarms 10 years from the date of manufacture. The date should be printed on the back of the alarm. If no date is visible, replace the alarm.

Locating Smoke Alarms

Smoke alarms should be placed on every level of the home and outside sleeping areas; e.g., in the hallways outside bedrooms.

Keep bedroom doors closed when sleeping to prevent smoke, toxic gases and flames from entering the room in case of fire.

Revised June 27, 2017