An initiative of New Jersey Agricultural Experiment Station and Rutgers Cooperative Extension

Frequently Asked Questions

This page is dedicated to answering some of the most Frequently Asked Questions associated with the SWPG’s Hazardous Waste Management Project. We are devoted to providing as much information as possible as a resource to all sectors of general public. If you have a question that is not mentioned here please e-mail your question to hayes@aesop.rutgers.edu.

Click on one of the following links to get your questions answered about:

Fluorescent Bulbs	Elemental Mercury
Computer Recycling	Mercury Devices

Fluorescent Bulbs 

Additional FAQs available at the GE Lighting website

Q: Why recycle fluorescent light bulbs?

A: There are significant benefits from recycling fluorescent lamps, since they contain hazardous materials (mercury) that are toxic to humans and the environment. Recycling greatly reduces the risk of the release of mercury into the environment which may result in health problems. Recycling also saves on the cost of pollution control at landfills, and the cost of air emissions treatments at incinerator facilities.

Q: How does a fluorescent light bulb work?

A: A fluorescent light bulb is a high efficiency lamp that uses an electric discharge through low pressure mercury vapor to produce ultra-violet (UV) energy. The UV excites phosphor materials applied as a thin layer on the inside of a glass tubes which makes up the structure of the lamps. The phosphors transform the UV to visible light.

Q: What is the composition of the mercury contained inside a fluorescent lamp?

A: Mercury remains in the vaporous form through it’s stay within the lamp.  The pressure within the lamp is kept very low, so when it is turned on mercury remains in the vapor stage.

Q: What is phosphor powder and how does it work?

A: An inorganic chemical compound processed into a powder and deposited on the inner glass surface of fluorescent tubes and some mercury. Phosphors are designed to absorb short wavelength ultraviolet radiation (from mercury vapor) and to transform and emit it as visible light.
http://www.nichia.com/phosphor.html

Q: Is phosphor power dangerous?

A:  A five-year study of phosphor by the Industrial Hygiene Foundation of the Mellon Institute found no significant adverse effects, either by ingestion, inhalation, skin contact, or eye implant.  Also, there have been no significant adverse effects on humans by any of these routes during the many years of its manufacture or use.  The phosphor is somewhat similar to the inert calcium phosphate-fluorides that occur in nature.  Phosphor is not phosphorous.  Heavy metals were removed from phosphor fifteen years ago or more.  At the end of lamp life mercury is attached to these phosphors.

Q: Is Phosphor powder the same as the powder used to make matches?

Q: What is a ballast?

A: A ballast is an auxiliary piece of equipment designed to start and properly control the flow of power to fluorescent lamps. Essentially, either end of a fluorescent lamp is connected into a ballast. Even though ballasts are replaced infrequently compared to fluorescent lamps, they should also be recycled. Fluorescent light ballasts manufactured before 1979 contain insulating compounds known as polychlorinated biphenyls (PCBs). PCBs are known to cause considerable environmental risk

A: Unlike a traditional incandescent light, a fluorescent lamp gradually weakens over time rather and does not usually "burn out" instantly. This occurs because there is a limited amount of time in which the mercury vapor can work effectively to activate the phosphor powder.

A: Fluorescent lamps have several important advantages. By choosing the proper type of phosphor, the light from such lamps can be made to approximate the quality of daylight. In addition, the efficiency of the fluorescent lamp is high. A fluorescent tube taking 40 watts of energy produces as much light as a 150-watt incandescent bulb. Because of this illuminating power, fluorescent lamps produce less heat than incandescent bulbs for comparable light production.

A: Recycling facilities that specialize in fluorescent lamps have machinery that is used to break down the fluorescent lamps in a safe way. The lamps will be separated into end caps, glass, phosphor powder, and elemental mercury in the following steps:

• Whole lamps enter the recycling process and undergo the initial glass breakage (argon gas is vacuumed out). End caps are separated from the glass and collected from the system, sampled, analyzed for mercury content, and shipped to an off-site metals recycling facility for their aluminum, brass and tungsten content.
• The glass is further processed to remove the residual phosphor powder coating. The glass drops into a collection container where it is sampled, analyzed for mercury content, and subsequently sent off-site for glass recycling.
• The powder with mercury and mercury vapor is conveyed through the system, separated in the cyclone separator, and accumulated in the hopper for further processing.
• The excess air from the cyclone separator is cleaned of all remaining dust in the baghouse air filter system. Dust-free air then passes through the carbon filtration system prior to discharge.

A: The presence of mercury is essential for fluorescent lamp operation. Electricity must pass through mercury gas in order to produce the ultraviolet energy that is converted into visible light by the phosphor coating. In fact, it is the mercury that gives fluorescent lamps their high-performance capabilities. Currently, there are no known replacements for mercury in the manufacturing process of fluorescent bulbs.

A: While there are not currently any known replacements for mercury, new fluorescent light bulbs are now being manufactured so that they contain up to 80% less mercury than standard fluorescent bulbs (Click here for more information from Philips.com). The mercury in fluorescent bulbs cannot be totally eliminated, but can be greatly reduced. Consumers are still urged to recycle all fluorescent light bulbs regardless of the amount of mercury they possess.

New types of fluorescent lamps known as compact fluorescent lamps (CFLs) are now on the market. These lamps are meant to provide light that is similar to that of incandescents, but with a higher energy efficiency.

Q: What are the similarities between fluorescent light bulbs and fluorescent minerals that glow in the dark?

Q: What are the similarities between fluorescent light bulbs and lava lamps?

A: There are not any significant similarities other than the fact that both need to be heated to work properly.  A fluorescent light bulb uses electrical current to heat mercury vapors inside the fluorescent tube.  A lava lamp uses a light bulb (it might be a fluorescent bulb) to heat the liquid and make is swirl around.  To find out more about lava lamps click here: http://www.howstuffworks.com/question36.htm.

For more information, please visit:

http://www.nichia.com/phosphor.html
--Basic info on phosphor in the bulbs.

http://www.electrochem.org/publications/interface/summer2003/IF6-03-Pages48-51.pdf
--A very technical description of the bulbs.

http://www.gelighting.com/na/downloads/lmi_sheet6.pdf
--A health safety sheet about florescent bulbs.

Elemental Mercury

Q: What is mercury?

A: Mercury is found naturally in the environment in several forms. In its elemental form, it is a shiny, silver-white, liquid metal used in thermometers and some electrical switches. It can be combined with other elements to form inorganic compounds. Mercury can evaporate to form colorless, odorless mercury vapors. Mercury can combine with organic material to form organic compounds such as methylmercury, which is produced primarily by bacteria and is the form which poses the greatest concern for environmental exposure.

A: Mercury in the form of methylmercury is of greatest concern, and the common route of exposure is ingestion. Methyl mercury is of particular concern because it can build up in certain fish to much higher levels and these fish that live in contaminated waters may then be eaten by people. Federal Food and Drug Administration (FDA) regulations prohibit the sale of commercial fish that are found to have high levels of methylmercury. Exposure may also result from breathing in air contaminated with mercury vapors. If handled directly, mercury can also be absorbed through the skin.

A: Exposure to high levels of elemental mercury vapor can result in nervous system damage including tremors, and mood and personality alterations. Exposure to relatively high levels of inorganic mercury salts can cause kidney damage. Adult exposure to relatively high levels of methylmercury through fish consumption can result in numbness or tingling in the extremities, sensory losses and loss of coordination.

Q: At what temperature does mercury freeze?

A: Negative 38^o Fahrenheit or negative 39^o Celsius.

Mercury Devices

A: Any household product that contains mercury is considered a mercury device. Some of the more common mercury devices include thermostats (non-electrical), thermometers and mercury switches. Since there are so many different products that may contain mercury, examining an electronic product label before you throw it away is recommended. If a product is labeled as a mercury device, we urge you to take the product to a recycling center rather than deposing of it in the curbside trash.

A: A mercury switch is a regulating device that uses mercury to perform "automatic" functions. It is a very small capsule containing mercury and is incorporated into many electronic products. For example, a mercury tilt switch is used in some space heaters so that if a space heater accidentally falls over, it will shut off automatically. When the space heater falls the mercury in the mercury tilt switch is displaced and causes the machine to shut off.

A: In general, if a mechanical switch is not visible in these items, a mercury switch is probably being used. The most common place where mercury switches are used is in thermostats (non-electrical). Mercury-containing tilt switches are found in or under the lids of clothes washers and chest freezers. They stop the spin cycle or turn on a light. They are also found in motion-sensitive and position-sensitive safety switches in old clothes irons and space heaters. Float switches are commonly used in sump pumps to turn the equipment on and off when the water is at a certain level. These switch devices are often visible. Mercury switches are also found in many places in automobiles and tractors.

A: Special machinery (see right) is used to separate elemental mercury from products which contain mercury switches. This mercury is then reused in the manufacturing of new mercury switches or any other new product that utilizes elemental mercury.

A: In some cases, yes.

· Several types of thermostats are now on the market that regulate temperature electronically rather than with a mercury switch (they have a digital display).

· Most new automatic irons have replaced the traditional mercury tilt switch with a switch that performs the same function without mercury. It is a switch that contains a tiny metal ball. The movement, or "tilt," of this ball indicates whether the iron has fallen over. Note: In many cases like the iron, mercury switches can be replaced more easily than in other cases. Some products simply cannot make use of a replacement switch because it cannot simulate certain properties of mercury. Some switches are required to perform more complex functions where only mercury can provide the solution.

Computer Recycling

A: There are several reasons why computer recycling has become an important issue in New Jersey and throughout the world:

1. The amount of obsolete computers in the waste stream is high due to the fact that computers are being replaced so frequently as technology improves. In general, sending garbage to landfills is becoming more and more of a problem because our landfills are reaching their capacity limits. Since computer and electronic waste accounts for a significant portion of the garbage in landfills, recycling can free up space in landfills for other trash.
2. Another important issue involved with computer recycling is the fact that computers have hazardous substances in their parts. The component of most concern is the cathode ray tube (CRT) inside of monitors. CRTs have approximately five to eight pounds of lead inside the glass. By recycling the CRTs we are ensuring that a hazardous substance like lead will not get into the environment.
3. Computer recycling also generates a large amount of raw materials that can be used to create new products like computers and other electronics. Any salvaged scrap materials and metals can be melted down and used in new products. Also, the smaller components like chips and motherboards from old computers can be reused in building new ones. Or, the old computer itself can be refurbished so that it works better and can be reused by someone who cannot afford or chooses not to purchase a brand new computer system.

A: In most cases all computer components can be recycled, that includes monitors, CPUs, printers, drives, modems, scanners and most other peripherals. Keyboards, mice, and other small peripherals can also be recycled although it is not cost effective for many recycling facilities because these items contain very little salvageable materials. That is why it is recommended that if you do wish to recycle a small peripheral you recycle it in combination with a larger one like a monitor or CPU.

A: Other electronic devices like televisions (which also use CRTs with leaded glass), VCRs, telephones, fax machines, and copiers can also be recycled by many recycling facilities, although some only recycle computers. While they might not pose as much of a hazard to the environment (with the exception of televisions), these other electronic products posses many of the same salvageable metals that computers have and can be recycled in a similar way.

NOTE: Microwaves and air conditioners are two major exceptions and should not be dropped off to be recycled. In the future the technology to recycle these items might become available. Therefore, you might wish to store them in your home until this occurs (if you have the space).

A: CRTs: The first step involves separating the tube from the rest of the monitor. The plastic housing and metals inside of a monitor can be recycled once the monitor is taken apart. Recycling the CRT, however, requires more effort. Some recycling facilities have specially machinery (like the CRT separation system shown below; from Newtech Recycling, Inc.) that enable them to recycle the tubes while minimizing human risk. CRTs are first decompressed to eliminated the explosive behavior of the tube. The tubes are then crushed, and the leaded glass is separated from the other materials. This leaded glass can then be melted down and recycled for the production of new CRTs in monitors and television sets. NOTE: In some cases, monitors do not have to be recycled. People sometimes will dispose of a monitor simply because it no longer has use for them not just because it does not work. Recycling facilities that specialize in remanufacturing and resale will first test whether or not the monitor is working. If it is working, it will be reused in combination with a refurbished computer system.

CPUs: There are three major directions in which computers can go, as far as recycling is concerned, when they have become obsolete:

1. Some computers are still working, but have been disposed of because they are old or have been replaced by a brand new system. In this case it still has a resale value. Certain recycling facilities specialize in upgrading these types of computers and will then resell them to interested buyers. In many cases facilities like these are able to sell refurbished computers in large quantities to schools and organizations at a discounted cost compared to buying a large quantity of brand new computers. Some facilities specialize in donation services and will donate these upgraded computers to needy non-profit organizations, schools, or individuals.
2. Some computers are simply too old or damaged to be upgraded or refurbished. In this case certain recycling facilities can actually demanufacture (take apart) the CPU and remove all of its parts. While the computer might not be useful as a whole unit, its parts like disk drives, chips and circuit boards can still be used in "rebuilt" computers. There are two primary criteria that determine the need to demanufacture and recycle a computer.  The first reason is the age of the PC and its ability to support current software and applications.  The rapid pace of technology continues to shorten the life cycle of a PC. The second reason to demanufacture and recycle a computer is the mechanical condition of the unit.  The costs to repair or upgrade a dysfunctional PC can often exceed the value of the system.


(Reusable computer parts)

3. All of the parts inside the computer that cannot be reused are then recovered simply for their precious and non-precious metals like copper, tin, and small amounts of low grade gold. Many recycling facilities only recycle computers in this way rather than reusing parts. The metals and plastics recovered from computers can be melted down and reused in the production on new computers or other electronics.

A: There are several reasons against this argument. The gold used in computers is not jewelry grade and so not as valuable as one might think. Also, the amount of gold found in computers is small compared to the other metals that are used. Thus, it would take a very large amount of computers to recover a reasonable amount of gold. For many people it would just take too much time and effort without much to show for it.

Some recycling companies specialize in the recovery of gold and other precious metals. They are able to make it cost effective to perform such a task because they have the help of special machinery that can easily separate gold and other precious metals from circuit boards.

A: The lead inside of the glass in monitors protects us from radiation that is given off by the computer monitor. This radiation can be harmful to us if the leaded screen was not there. An alternative to using monitors that contain lead would be to use an LCD screened monitor (like the ones used for laptops).

A: No, the screens used for laptop computers use LCD technology and do not have leaded glass.

A: Yes. Laptops should also be recycled. We are especially concerned with laptop batteries, which contain toxic materials.  Laptops also contain a small, mercury-containing, fluorescent light bulb which is used to illuminate the LCD screen.

A: Other toxic substances like mercury, arsenic, cadmium, and PCBs are used in computers. They can be found within the circuitry of various components within the CPU. Therefore, it is important to recycle CPUs along with computer monitors.

A: It would be great to just send away our trash and not have to worry about it again. Unfortunately, to send all our garbage into space it would take thousands of launches, and with each launch being so costly, it just wouldn’t make sense to send all our garbage into space.

Q: How much mercury is found inside a computer?

A: Note: the following is preliminary data and not is yet confirmed.  
A standard desktop computer possesses .001 grams of mercury found in the printed wiring board.  A laptop computer possesses this amount as well in addition to .5 grams found in a mercury switch.  (Mercury switches are explained in more detail on this informational page).

Q: How does a television or computer monitor work

A: The following website explains in detail the process behind how televisions and computer monitors work: http://www.howstuffworks.com/tv1.htm.

Q: Is the lead solder (used in circuit boards) hazardous to the touch?

A: Like lead paint, the leaded soldering found in the circuitry of computers should not be ingested.  To avoid the risk of lead poisoning, computers should not be disassembled in the home and should be recycled appropriately.