Frequent Questions About EPA's Mercury Lamp Drum-Top Crusher Study
On this page:
1. What are drum-top crushers (DTCs)?
2. Why did we do the Mercury Lamp Drum-Top Crusher Study?
3. What does the Mercury Lamp Drum-Top Crusher Study show?
4. Should drum-top crushers be used in the management of fluorescent lamps?
5. Are drum-top crushers safe to use?
Drum-top crushers are devices that are designed to safely crush fluorescent lamps. DTCs fit on the top of a 55 gallon drum and crush the fluorescent lamps into the drum below. These devices are used to reduce the volume of waste lamps, so as to improve storage and handling and reduce shipping costs of waste lamps to make it easier to recycle them. They also are designed to prevent the release of mercury that is a key component of fluorescent lamps.
Hazardous waste lamps were added to the federal list of universal wastes on January 6, 2000. The preamble identifies lamp crushing as Resource Conservation and Recovery Act (RCRA) treatment and specifically prohibits the use of DTCs for management of fluorescent lamps as universal waste unless an equivalency determination is made. The purpose of the Study is to make information available to states and regions that could eventually be used to provide “a demonstration of equivalency to the federal prohibition [on treatment of universal waste without a permit]” (volume 64 of the Federal Register page 36465).
Three of the four devices included the Study usually maintained mercury levels within a containment structure, constructed for the Study, below the Occupational Safety and Health Association (OSHA) Permissible Exposure Limit (PEL) of 0.1 mg/m3. One device generally maintained mercury levels below the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 0.025 mg/m3 during normal lamp crushing operations. The fourth device failed to maintain mercury levels below the OSHA PEL, even when only low-mercury lamps were crushed (nine of the 12 air samples collected for this device were above the PEL and four of the 12 air samples were more than three times the PEL). This device was eliminated from the Study after two rounds of testing because of concerns about operator health and safety.
[NOTE: The results from the Study were generally collected over time periods between one and three hours. Results were not adjusted to represent eight-hour, time-weighted averages (TWA).]
This Study also demonstrated that during operation of the three DTCs that completed the Study, the operator was, at times, exposed to levels of mercury above the TLV and PEL values. Higher exposures typically occurred when a DTC had to be taken off of a drum because the drum was full. This procedure allowed the drum to be open to the room for several minutes.
The Mercury Lamp Drum-Top Crusher Study presents the findings of the DTC Device Study. EPA encourages states to review the Study carefully as they determine whether, and under what circumstances, to allow the use of DTCs.
Recycling of spent lamps represents one of the best ways to control the release of mercury to the environment from landfilling of fluorescent lamps, by keeping mercury out of landfills in the first place. Recycling can be done either on an individual lamp basis (i.e., sending whole, boxed lamps to a recycler), or by using a DTC at the point where lamps are removed from service. Use of DTCs has obvious appeal in that the devices reduce lamp volume, allowing several hundred crushed lamps to occupy the space that 40 or 50 whole lamps would occupy, thereby reducing storage and shipping costs.
Pre-crushing the lamps also has the advantage of allowing shipping to the recycler in a well-sealed, durable container that is unlikely to release substantial amounts of mercury during shipment, while a significant fraction of whole lamps can be broken during shipment, releasing mercury.
Despite these advantages, the DTCs evaluated as part of this Study all released some mercury when used and so have the concern of creating new sources of mercury exposure. The DTC operator and any assistants handling lamps or working directly with the DTC are the most obvious new exposures. Less direct mercury exposures that could be created by DTC use include anyone working in or visiting buildings in which DTCs are used. The only way to eliminate these unnecessary indirect mercury exposures would be to keep the ventilation of the lamp crushing room completely separate from the general building ventilation system as is done at large-scale, industrial lamp recycling facilities.