All states have laws (statutes) that require landlords to install and maintain smoke detectors in leased residential premises (apartments, homes).

Some states such as Iowa, Maine, Massachusetts, Ohio, and Vermont require photoelectric or ionization sensors—at least in new construction. And Oregon requires smoke detectors with a HUSH mechanism that allows the alarm to be silenced or temporarily desensitized for 7 minutes while a known condition such as cooking is causing the alarm to activate.

Most states also require landlords to install and maintain carbon monoxide detectors in leased residential premises. Smoke and carbon monoxide detectors are widely available in the same device.

In Delaware, landlords are required by law to install and maintain smoke detectors in leased residential premises. Delaware's regulations stipulate that smoke detectors must be present on each level of the residence and outside sleeping areas. The state law aligns with the National Fire Protection Association's recommendations for smoke alarm installation. Additionally, Delaware mandates the installation and maintenance of carbon monoxide detectors in all rental units that have fuel-burning appliances, have an attached garage, or are otherwise at risk for carbon monoxide exposure. These requirements are designed to ensure the safety and well-being of tenants by providing early warning in the event of a fire or carbon monoxide presence. It is important for landlords to comply with these regulations to avoid legal liabilities and to ensure the safety of their tenants.