Understanding Smoke and Carbon Monoxide Detector Law and Functionalities
Single family and multi-family residential properties sold in Massachusetts must be inspected by the fire department to confirm compliance with safety regulations. This protects everyone living in the residence.. The fire department checks for working smoke detectors and carbon monoxide detectors. They then issue a smoke certificate required for the closing. It is essential for all property owners to know the Massachusetts smoke detector laws and smoke detector technologies and to comply (even if they are not selling their property).
Smoke Detector Types and Functionalities
There are two primary types of smoke detectors, Ionization and Photoelectric. Each responds to the two elements, smoke and fire, in different ways. It is important to understand the pros and cons of their responsiveness to these elements. In the event of an alarm one will can asses the situation understanding potential that some a mis-signal and prepare themselves to act (escape, protection, progress—in the event of a real fire) based on that understanding.
Ionization Smoke Detectors
Ionization detectors have two electrodes, and a constant current communicated between them. In the event of a fire, smoke is the element that interferes with the current and initiates the alarm. However, this alarm is also triggered by steam as well. Since the alarm cannot discriminate between smoke and steam, they are likely to issue false alarms when placed near kitchens or baths.
- Pros:
-Better (than Photoelectric alarm) at detecting smoke produced from flaming fires
- Cons:
-Cannot discriminate between smoke and steam.
-Slower at detecting smoke produced from smoldering fires.
Photoelectric Smoke Detectors
Photoelectric smoke detectors have a light beam. Smoke or fire can scatter the beam and trigger the alarm. It is more effective at recognizing smoldering fire and is less sensitive to false alarms from cooking smoke or shower steam. Overall, they are more technologically advanced, reliable and efficient than Ionization alarms.
- Pros:
-Faster (than Ionization alarm) at responding to smoke produced from Smoldering fires. –Less sensitive to detect a false alarm from cooking smoke or shower steam
- Cons:
-Slower at detecting smoke produced from flaming fires
In addition to these detectors, it is also mandatory to have a carbon monoxide detector installed.
What Carbon Monoxide is and Why You Need a Detector
Carbon Monoxide (CO2) is a colorless, odorless, toxic gas created any time you burn fuel. Any fuel burning appliance, vehicle, tool or other device has the potential to produce dangerous levels of CO2 gas and poison people and animals who breathe it. Examples of CO2 producing devices commonly in use around the home include:
- Automobiles
- Charcoal grills
- Fireplaces and woodstoves
- Fuel fired furnaces (non-electric)
- Gas dryers
- Gas stoves
- Gas water heaters
You have some freedom to choose the kind of carbon monoxide alarm based on how it operates (batter-powered, hardwired, combination smoke and carbon monoxide alarms etc).
Melrose MA Smoke Detector Laws
Melrose MA rules determine the kinds and locations of smoke detectors in single family and 2+-family homes. The details differ depending on when a property was constructed or renovated. The following is an overview of the location of smoke detectors within a home.
| Location | Before Jan 1, 1975 | 1975 to Aug. 27, 1997 | after Aug. 27, 1997 | on or after Jan. 1, 2008 | on or after Feb. 4, 2011 |
| Power Supply | Hardwired or Battery |
Hardwired Interconnected |
Hardwired Interconnected Battery Backup |
Hardwired Interconnected Battery Backup |
Hardwired Interconnected Battery Backup |
| Every Finished Level | Y | Y | Y | Y | Y |
| Bottom of Each Stairway | Y | Y | Y | Y | |
| Outside Every Sleeping Area | Y | Y | Y | Y | Y |
| Minimum 1 for Every 1,200 sq.ft. Living Space per Floor | Y | Y | Y | Y | |
| Inside All Bedrooms | Y | Y | Y | ||
| In Basement | Y | ||||
| Base of Each Stairway to a finished level | Y | ||||
| Within 20ft. of Kitchens/Baths | Photoelectric | Photoelectric | Photoelectric | Photoelectric | |
| Outside of 20ft. of Kitchens/Baths | Both Ionization & Photoelectric | Photoelectric OR Dual | Photoelectric |
Additional Regulations
In order to receive a verified certificate of inspection from a local fire marshal, these are some of the minimum requirements:
- All preventative fire systems are required to be photoelectric or combination
- All systems must have sealed, non-replaceable 10-year batteries.
Carbon Monoxide Alarms:
| Location | before Jan 1, 1975 | 1975 to Aug. 27, 1997 | after Aug. 27, 1997 | on or after Jan. 1, 2008 | on or after Feb. 4, 2011 |
| Power Supply | battery powered, plug-in with battery backup, hardwired with battery backup, or system type. | battery powered, plug-in with battery backup, hardwired with battery backup or system | battery powered, plug-in with battery backup, hardwired with battery backup, or system type and may be mounted on the walls. | Must be hardwired and interconnected with battery backup. (May be separately wired from the existing smoke detection system.) | Hardwired Interconnected Battery Backup (May be separately wired from the existing smoke detection system.) |
| Combination Detector | Same mounting instructions as Smoke alarms | Follow same location as smoke alarms: hardwired with battery backup and mounted on ceiling | Follow same location as smoke alarms: hardwired with battery backup | Y | Y and mounted on ceilings |
| Mounted on Walls | Battery powered or plug in with battery backup CO detectors | CO detectors (Power Supply allowed is same as above) | |||
| Within 10ft of each bedroom door | Y | Y | Y | Y | Y |
| Every Finished Level | Y | Y | Y | Y | Y |
More information on Melrose MA smoke detector laws may be found at:
http://www.mass.gov/eopss/agencies/dfs/dfs2/osfm/fire-prev/smoke-alarm-regulations.html.
More information regarding these specifics and requirements for heat alarms can be found at:
Note that the above information is only an overview, must not be considered legal advice and may change in the future. Furthermore, cities/towns may impose stricter rules beyond the state ones. Speak with your local fire department to request comprehensive and up-to-date laws for your home.