Mercury and Mercury-Containing Equipment

Elemental mercury is liquid at room temperature, with a metallic and shiny appearance. It is conductive and highly volatile. Mercury can have serious health impacts on humans.

Disclaimer: The information below is intended to serve as a guide to responsible waste management and does not supersede Delaware’s Regulations Governing Hazardous Waste (7 DE Admin. Code 1302). Regulations specific to Mercury Wastes can be found in the regulations.

In some cases, mercury wastes may fall under the Universal Waste Rule.

Mercury Affects Human Health and the Environment

Exposure to high levels of mercury has been linked to nervous system and developmental problems in humans, especially children. Depending on the amount of exposure, health effects can range from minor losses of sensation or mental ability to tremors, inability to walk, convulsions and even death.

Improper treatment, disposal and management of mercury-bearing wastes, mercury-containing devices and elemental mercury can contribute to mercury exposures. Mercury vapor released in the air eventually settles into water or onto land where it can later be washed into water. Once mercury enters water, biological processes transform it to a highly toxic form (methylmercury) that builds up in fish and animals that eat fish. People are exposed to mercury primarily by eating fish, which can potentially result in health problems.

Devices that Contain Mercury

While not a complete list, the following items may contain mercury and must be properly assessed before disposal:

A Note About Fluorescent Lamps

While fluorescent lamps do contain mercury, when spent, lamps should be managed as their own universal waste stream, not as a mercury-containing device.

  • Fluorescent lamps, including tanning bed lamps
  • Switches within older model refrigerators, chest freezers, washers, dryers and other appliances
  • Thermostats
  • Silent wall switches manufactured before 1991
  • Commercial/industrial heating and cooling equipment
  • Elemental mercury compounds
  • Float switches
  • Gas-fired devices with pilot lights and flame sensors (ex. gas Ranges and ovens)
  • Manometers/barometers
  • Dental amalgam
  • Mercury thermometers

Managing Mercury-Containing Devices

Mercury-containing devices must be managed as a hazardous waste in accordance with the requirements of Delaware’s Regulations Governing Hazardous Waste as applicable to your site’s generator category classification or as a universal waste in accordance with Part 273 of the Regulations.

The Universal Waste Rule and Mercury-Containing Devices

Under the Universal Waste Rule, some wastes may have less stringent management standards, depending on the amount of wastes managed.

While mercury-containing devices can be managed as hazardous waste, the Universal Waste Rule is designed to simplify their management.

When managing mercury-containing devices as universal waste you need to store the devices in a suitable leak-proof container, labeled “Universal Waste – Mercury Containing Equipment,” “Waste Mercury – Containing Equipment,” or “Used Mercury – Containing Equipment.”

If breakage occurs see the information on mercury spills, below.

If removing the original housing of a non-ampule mercury-containing device, you must immediately seal the original housing holding the mercury with an air-tight seal to prevent the release of any mercury to the environment.

To dispose of these devices, either send or take them to a mercury recycler. Be sure to discuss proper shipping methods with the recycler.

What to Do About a Mercury Spill

DNREC Emergency Response


When liquid mercury is spilled, it forms droplets that can accumulate in the tiniest of spaces and then emit vapors into the air. Mercury vapor in the air is odorless, colorless, and very toxic.

Most mercury exposures occur by breathing vapors or by direct skin contact.

Be careful to keep devices from breaking and releasing mercury into the environment. Health problems caused by mercury depend on how much has entered your body, how it entered your body, how long you have been exposed and how your body responds to the mercury.

All mercury spills, regardless of quantity, should be treated seriously.

The Division of Public Health (DPH) can offer assistance following exposure to any level of mercury. Contact the Division of Public Health at 302-744-4540.

In the event a spill or other incident leads to the release of one pound or more of mercury, you are subject to Delaware’s Reporting of A Discharge of A Pollutant or Air Contaminant Regulations (7 DE Admin. Code, 1203). When such a release occurs Environmental Emergency Notification needs to be made to DNREC by calling 1-800-662-8802.

It is also necessary to report the release to the State Emergency Response Commission and your Local Emergency Planning Committee.

Disposing of Fluorescent Lamps

Please see Managing Fluorescent Lamps. Delaware’s Regulations Governing Hazardous Waste prohibit disposal of any hazardous waste into a solid waste landfill, such as those operated by the Delaware Solid Waste Authority. Delaware generators of hazardous waste may not use these landfills as a disposal option.

Satellite Accumulation Areas

Mercury or mercury-containing devices may be managed as hazardous waste in a satellite accumulation area. (§262.15(a))

All containers must be closed, unless waste is being added or removed, and marked with the words “Hazardous Waste” and a description of the hazard of its contents. The containers must be compatible with the waste within and maintained in good condition. (§262.15(a)(1-5))