Fire Safety Concerns for Aluminum Wiring in Homes

This article was written by Captain Trey Foust of the Loveland-Symmes Fire Department

Loveland and Symmes Township, Ohio – During the 1960’s and 1970’s, aluminum wiring became a popular choice for electrical installations in homes. It was seen as an affordable alternative to copper wiring, which had become expensive due to high demands for copper. However, over the years, it has become evident that aluminum wiring poses significant safety risks, in relation to fire hazards. Residents may be at a greater risk of a fire if their home has aluminum wiring.

The Risks of Aluminum Wiring

The primary safety concern with aluminum wiring lies in its material properties and the way it interacts with electrical systems over time.

Key risks associated with aluminum wiring:

• Thermal Expansion & Contraction: Aluminum expands and contracts more than copper when exposed to the heat generated by electrical currents. Over time, this expansion and contraction can loosen connections, leading to arcing and overheating, both of which significantly increase the risk of fire.
• Oxidation: Aluminum reacts with oxygen in the air to form aluminum oxide, a substance that is less conductive than the base metal. This oxidation increases resistance at connections, causing them to heat up and potentially ignite nearby flammable materials.
• Galvanic Corrosion: When aluminum wiring is connected to copper wiring or terminals, a chemical reaction called galvanic corrosion can occur. This process deteriorates the connection, leading to increased resistance and heat generation.
• Brittleness: Aluminum is softer and more prone to damage than copper. Over time, aluminum wires can become brittle, increasing the likelihood of breaks or fractures, which can lead to arcing and sparks.

Signs of Potential Issues

Homeowners with aluminum wiring should be aware of warning signs that could indicate electrical problems, such as:

• flickering lights;
• unusual warmth or discoloration around outlets or switches;
• a smell of burning plastic;
• sparking when plugging in or unplugging appliances.

Fire Statistics

Studies have shown that homes with aluminum wiring are more likely to experience electrical fire compared to homes with copper wiring. According to the U.S. Consumer Product Safety Commission (CPSC), homes built with aluminum wiring are 55% more likely to have a fire hazard at connections than homes with copper wiring.