CPSC Safety Recommendations For Aluminum Wiring In Homes

June 1, 1974
Release Number: 74-040

The U.S. Consumer Product Safety Commission held four days of fact-finding hearings on March 27 and 28 in Washington, D.C., and on April 17 and 18 in Los Angeles, California, to seek information about possible hazards associated with the use of aluminum in home electrical wiring systems.

The Commission has received numerous reports about home fires that have been attributed to the use of aluminum conductors in branch circuits. Many of these fires have been the result of overheated terminals involving aluminum wiring and a receptacle or switch.

The Commission currently is evaluating the data presented at the hearings by consumers and representatives of industry and government and conducting additional tests at the National Bureau of Standards to better understand the failure mechanism. Further action by the Commission is dependent upon a finding that aluminum wiring is either a substantial product hazard or poses an unreasonable risk of injury to consumers.

An estimated two million homes and mobile homes have been constructed using aluminum wiring since 1965.

To assist consumers who live in homes with aluminum wiring to reduce the potential risk of fire and the possibility of dangerous overheating, the Commission suggests the following precautionary steps.

CONSUMERS WHO HAVE NOT HAD THOROUGH ELECTRICAL TRAINING SHOULD NOT ATTEMPT TO INSPECT THEIR HOME WIRING SYSTEM OR MAKE ANY ELECTRICAL REPAIRS OR ADJUSTMENTS BEFORE SEEKING EXPERT ADVICE. SERIOUS OR FATAL ELECTRIC SHOCK COULD RESULT.

  1. If you are not certain or if you do not know whether your home is wired completely with aluminum, ask a knowledgeable electrician or other qualified individual to make the determination. If aluminum wiring was used, have the electrician or individual check the connections on heavily loaded and constantly loaded circuits to determine if the electrical connections have been made properly or show evidence of deterioration.

  2. Trouble signals associated with aluminum wiring problems include:

    * warm switch or receptacle face plates.
    * strange or distinctive odor or the smell of burning plastic in the vicinity of a receptacle or switch.
    * flickering of lights not traceable to appliances or obvious external causes.

    IF THESE TROUBLE SIGNALS ARE PRESENT IN YOUR HOME, SEEK EXPERT ADVICE IMMEDIATELY.

  3. If it is necessary to replace wall switches and receptacle outlets, only devices which are designed specifically for use with aluminum wiring should be used. These devices are labeled CO/ALR on the mounting strap.

    Proper installation of the CO/ALR device is critical. The work should be performed only by a qualified electrician or individual familiar with the techniques of using aluminum wiring. Proper techniques include the ability to remove the wire insulation without nicking the wire, to wrap the wire with proper distance and direction around the terminal screw, to tighten the screw with the proper torque, and to position the wires within the outlet box to avoid loosening the terminal connection. Complete installation procedures are available at no cost by writing to Aluminum Wire Installations, U.S. Consumer Product Safety Commission, Washington, D.C. 20207.

  4. Pigtailing. A technique called pigtailing is sometimes used to improve aluminum wiring connections. Pigtailing involves connecting a short piece of insulated copper wire between the aluminum wire and the switch or receptacle connecting terminals. Although this technique may be an acceptable practice for new installations, the addition of more wires and splices into existing outlet boxes is not generally recommended.