A ballast is a device designed to regulate the voltage within an electrical circuit. This page addresses only ballasts used in circuits containing electric gas-discharge lamps. Examples of gas-discharge light sources include neon and fluorescent lights and high-intensity discharge (HID) lamps.

The ballast is designed to provide high initial voltage to start the lamp, then decrease voltage quickly to a stable operating level. Ballasts may contain a variety of hazardous materials and must be handled and disposed accordingly. Ballasts of any type should, and in some cases are required to be, recycled.

Types of ballasts

There are two principal types of ballasts used in electric lamp circuitry, magnetic and electronic.magnetic ballast

Magnetic ballasts use a coil wrapped around a metal core, essentially an electromagnet, to generate an inductive field that affects the voltage flowing through the coil wire. Because they work at a lower cycle than electronic ballasts, you may notice a flicker or hear a hum coming from fixtures containing electromagnetic ballasts. Prior to 1980, the dielectric fluid and potting material in magnetic ballasts contained polychlorinated biphenyls (PCBs), a highly regulated, highly toxic carcinogen. Congress banned the manufacture of PCBs in 1977 and banned their use in 1979 in all but totally enclosed equipment. From 1979 through 1991, Di (2-ethylhexyl) phthalate (DEHP), another toxic hazardous material, was used to replace PCBs in certain ballast capacitors.

Electronic ballasts use semi-conductor circuitry to regulate the current flowing through the lamp. The electronic components that compose an electronic ballast are smaller and lighter than the core and coil assembly of a magnetic ballast. Thus an electronic ballast can weigh less than half as much as a magnetic ballast of the same size.

Different lamps require specific ballasts designed to maintain current levels needed for varying tube designs. Using a mismatched lamp and ballast can shorten the life of all components and increase the possibility of overheating, failure and leakage.

Safe handling

University of Wisconsin supervisors and their employees who handle lamp ballasts are subject to the Hazard Communication Standard and other worker protection provisions. Safety glasses should be worn. Gloves should be neoprene, Viton or some other material resistant to breakthrough and permeation of PCBs. Handle ballasts as few times as possible.


PCBs are regulated federally under 40 CFR 761 and in Wisconsin under NR 157.

Disposal considerations

Ballasts originating at University of Wisconsin campuses should be recycled.

PCB ballasts

As mentioned above, prior to 1980, ballasts contained polychlorinated biphenyls (PCBs). PCB ballasts must be recycled using the State of Wisconsin lamp and ballast recycling contract.

Store ballasts in the proper DOT specification container. Mark/label the container with a yellow PCB label and the out-of-service date. Veolia offers the following containers for storage and transport:

  • Red steel open top 55-gallon drum – UN rating 1A2/X400/S – weight capacity 880 pounds. This is the drum that is typically provided to customers that are shipping large volumes of ballasts. The drum should only be filled 2/3 full. The weight capacity of the drum may be 880 pounds but heavy drums are difficult for personnel to move so we do not recommend filling the container all the way to the top.
  • Black steel open top 55-gallon drum – UN rating 1A2/Y1.2/100 – weight capacity 550 pounds. These drums are sometimes substituted for the red drums if the red drums are out of stock. The drum should only be filled 2/3 full.
  • 5g poly pail – UN rating 1H2/Y30/S – weight capacity 66 pounds. Pails typically can hold sixteen ballasts from 4’ fixtures and 8 ballasts from 8’ fixtures.
  • 30 gallon steel open top drum – UN rating 1A2/Y1.2/100. Weight capacity is 300 pounds.

PCB ballasts must be destroyed within one year from their out-of-service date. Allow sufficient time to schedule a pickup and for transport and disposal. PCB shipments must be documented on a Uniform Hazardous Waste Manifest. Container weights must be in kilograms (kg). Do not send any copies to DNR if the container has no other waste code. Ensure that you receive a Certificate of Disposal.

Non-PCB magnetic ballasts

Ballasts manufactured after 1979 may contain a label stating “No PCBs”. Magnetic ballasts which don’t have such a label should be assumed to contain PCBs. Non- PCB ballasts may be recycled using the State of Wisconsin lamp, ballast and battery recycling contract. They may be segregated from PCB ballasts for a cost savings or mixed with and disposed as PCB ballasts.

Electronic ballasts

Electronic ballast are likely to fail the TCLP test for lead. Electronic ballasts may also be recycled using the State of Wisconsin lamp, ballast and battery recycling contract either as ballasts or as electronic waste.

Additional resources

NR 157


This publication was prepared for environmental, health and safety staff at University of Wisconsin System campuses, to assist in finding resources and information for regulatory compliance. It is not intended to render legal advice.

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