23,700
Residential building fires from electrical malfunction
U.S. fire departments responded to an estimated 23,700 residential building fires caused by electrical malfunction in 2023.
U.S. Fire Administration · 2023 data ↗APPLICATION / FIREXNULL
Supplemental Fire Suppression for Outlet and Switch Boxes
FXN-S1 Outlet Guard is designed for compatible indoor electrical outlet and switch boxes. Select the appropriate pack size and follow installation guidance.
FireXNull products are designed as supplemental protection, not as substitutes for code-required fire protection systems. Review technical documentation and confirm fit for the application.
IN SHORT
Passive Fire Suppression Inside Outlet and Switch Boxes.
FXN-S1 adds passive, heat-activated fire suppression inside compatible indoor electrical outlet and switch boxes. One 0.75 x 0.75 in (nominal) sticker installs per compatible gang and releases FK-5-1-12 clean agent at 248°F ± 9°F (120°C ± 5°C). It needs no power or wiring. It is supplemental protection: it does not prevent electrical faults or replace breakers, AFCI or GFCI protection, smoke alarms or code-required fire safety measures.
01 / THE CONTEXT
Electrical Malfunction Is a Persistent Home Fire Cause.
Electrical malfunctions continue to start tens of thousands of residential fires in the U.S. every year.
305
Deaths in 2023
These electrical malfunction fires caused an estimated 305 deaths and 800 injuries in 2023.
U.S. Fire Administration · 2023 data ↗$1.5B
Direct dollar loss in 2023
Residential electrical malfunction fires caused an estimated $1.5 billion in direct dollar loss in 2023.
U.S. Fire Administration · 2023 data ↗Context: these figures cover all U.S. residential building fires attributed to electrical malfunction, not only fires that start in outlet or switch boxes. They do not measure how FXN-S1 would perform in any specific installation.
02 / LOCALIZED ELECTRICAL RISKS
Focus on the Connections Behind the Wall Plate.
A loose terminal, worn device or overheating connection inside an outlet or switch box can become an ignition source behind the wall plate, where it cannot be seen. FXN-S1 adds a localized layer inside the box itself.
- Receptacle (outlet) boxesEnclosed indoor boxes behind wall outlets.
- Switch boxesEnclosed indoor boxes behind wall switches.
- Multi-gang boxesOne FXN-S1 per compatible gang. Do not stack stickers.
- Old-work and new-work boxesResidential and light commercial boxes, subject to available clearance.
- Panels and larger enclosuresUse FXN Sticker models sized by enclosure volume, not FXN-S1.
03 / AN ADDED LAYER OF PROTECTION
One Sticker Per Gang. Inside the Box.
FXN-S1 works inside the box, where wall-mounted smoke alarms and circuit protection do not reach. It adds to those protections and never replaces them.
Where It Fits in Home Electrical Safety
On a phone, scroll sideways to see all columns.
| Layer | Scope | How it works | Role |
|---|---|---|---|
| Correct installation and inspection | Wiring, devices and connections | Work by a qualified electrician, with periodic inspection | Prevents many electrical problems at the source |
| Breakers, fuses, AFCI and GFCI protection | Circuits | Respond to overcurrent, arc faults or ground faults | Interrupts many electrical faults |
| Smoke alarms and sprinklers | Rooms and building | Smoke detection, or heat at the sprinkler head | Warns occupants and provides code-required protection |
| FXN-S1 | Inside one compatible box | Heat at the sticker reaches its activation temperature | Supplemental, localized layer at the likely ignition source |
FXN-S1 does not send an alarm signal, does not identify the electrical problem and does not replace any of these layers.
FXN-S1 Outlet Guard
Compact sticker for compatible indoor outlet and switch boxes. Available in 4, 12 and 100 packs.
Shop FXN-S1 →FXN Sticker S Series
For electrical panels, cabinets and other small enclosures, select an FXN Sticker model by enclosure volume.
Compare FXN Stickers →Contractor and Bulk Quantities
For electrical contractors, builders and property managers protecting many boxes across a project or portfolio.
Ask About Bulk Quantities →04 / FXN-S1 SPECIFICATIONS
Key Specifications.
Reference values from the current FXN-S1 Technical Data Sheet.
On a phone, scroll sideways to see all columns.
| Property | Specification |
|---|---|
| Format | Adhesive-backed sticker, 0.75 x 0.75 x 0.04 in (nominal) |
| Activation temperature | 248°F ± 9°F (120°C ± 5°C) |
| Quantity | One FXN-S1 per compatible gang. Do not stack stickers or install more than one per gang |
| Pack sizes | FXN-S1-4, FXN-S1-12 and FXN-S1-100, covering up to 4, 12 and 100 gangs |
| Placement | Upper-left or upper-right clean, dry, flat interior surface of the box, clear of wires, terminals, connectors and device components |
| Operating environment | Enclosed indoor boxes only. Sustained ambient at or below 149°F (65°C), up to 80% RH, non-condensing. Not for use where condensation is present |
| Service life | Single use. Activation may not be externally visible. Replace after any known or suspected activation. Recommended replacement up to 5 years after installation |
| Storage | Up to 2 years from date of manufacture in original sealed packaging |
Source: TDS-FXN-S1-001-US V1.0 (September 2026). Last updated October 2026. Performance depends on correct installation, adhesion, clearance, box conditions and fire conditions. Fire prevention or suppression is not guaranteed.
05 / THE CLEAN AGENT
Why a Clean Agent Behind the Wall Plate.
FXN-S1 uses microencapsulated FK-5-1-12, an electrically non-conductive clean agent that evaporates without leaving a residue. When heat at the sticker reaches its activation temperature, the capsules release the agent inside the box, close to the source. No wiring, power supply or detection hardware is required.
After any known or suspected electrical event, stop using the outlet or switch and have a qualified electrician inspect the device, wiring and connections before restoring normal use. How the technology works →
06 / BEFORE YOU INSTALL
Check the Box First.
Install only in accordance with the FXN-S1 Safety, Installation and Use Guide supplied with the product. Before installing, confirm:
- Power is off at the circuit breaker and the circuit is verified de-energized. If you cannot verify this safely, contact a licensed electrician.
- The box is an enclosed indoor outlet or switch box with a clean, dry, flat mounting area.
- There is enough clearance that the device and cover plate close without force.
- The sticker will stay clear of wires, terminals, connectors and device components.
- The installation date and replacement date are recorded for each box.
07 / COMMON QUESTIONS
Common Questions.
Does FXN-S1 prevent electrical fires?
No. FXN-S1 does not prevent electrical faults. It provides supplemental, early-stage suppression inside the box when the temperature at the sticker reaches its activation threshold.
Does it replace breakers, AFCI or GFCI protection or smoke alarms?
No. FXN-S1 complements those protections and code-required fire safety systems. It does not replace any of them.
How many do I need?
One FXN-S1 per compatible gang. A two-gang box with two compatible gangs uses two stickers. Do not stack stickers.
Can I install it myself?
Only with the power off at the breaker and the circuit verified de-energized, following the FXN-S1 Safety, Installation and Use Guide. If you cannot verify this safely, contact a licensed electrician.
How do I know if it has activated?
Activation may not be externally visible. Inspect the sticker whenever the box is opened with the power off. After any known or suspected electrical event, stop using the outlet or switch, have a qualified electrician inspect it and replace FXN-S1.
Can it be used outdoors or in damp locations?
No. FXN-S1 is for enclosed indoor boxes only and should not be used where condensation is present or where the sustained ambient exceeds 149°F (65°C).
How long does it last?
The recommended replacement is up to 5 years after installation under specified conditions. Unopened packs can be stored for up to 2 years from the date of manufacture.
Can I use FXN-S1 in an electrical panel?
No. For electrical panels, cabinets and other enclosures, select an FXN Sticker model sized by enclosure volume.
Is FXN-S1 UL Listed or FM Approved?
No. FXN-S1 is not UL Listed or FM Approved as a fire suppression product.
FXN-S1 is supplemental protection. It does not replace correct electrical installation, inspection, maintenance or repair, circuit protection, smoke alarms or code-required fire safety measures. Fire prevention or suppression is not guaranteed.
Related applications: Wire Connections & Terminals · Industrial Control Panels & Switchgear · FAQ · Safety Data Sheets
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