Thursday, March 5, 2015

Heavy Metal Waste Regulation: Which Substances Make Up the RCRA 8 Metals?

What are the RCRA 8 Metals?

The Resource Recovery and Conservation Act (RCRA) lists and monitors a group of eight heavy metals which are commonly referred to as the RCRA 8. The reason being, each of these eight metals is extremely toxic at even small concentrations.
So the amount of each metal present in waste is highly regulated, and the waste can be made up from everything from light bulbs to batteries. So learning each metal and their allowable amounts is crucial.
The RCRA 8 metals are,
  • Arsenic (As),
  • Barium (Ba),
  • Cadmium (Cd),
  • Chromium (Cr),
  • Lead (Pb),
  • Mercury (Hg),
  • Selenium (Se), and
  • Silver (Ag).

The EPA Allowable Limits in Waste: An Overview

The Environmental Protection Agency (EPA) allows for only a certain concentration of each metal in waste. For a look at the limits and the hazardous waste codes set out by the agency, refer to the chart below:
Heavy MetalHazardous Waste CodeEPA Allowable Limits
ArsenicD0045.0 ppm (mg/L)
BariumD005100.0 ppm (mg/L)
CadmiumD0061.0 ppm (mg/L)
ChromiumD0075.0 ppm (mg/L)
LeadD0085.0 ppm (mg/L)
MercuryD0090.2 ppm (mg/L)
SeleniumD0101.0 ppm (mg/L)
SilverD0115.0 ppm (mg/L)

A Breakdown of the RCRA 8 Metals

Arsenic, typically thought of as the de rigueur poison of the nobility in during the Middle Ages, is actually found in small—but harmless—concentrations in our food and water today. Due to its prevalent use and misuse in the historical record, its toxicity is well known. The presence of toxic arsenic in tobacco smoke has also been well-documented. The EPA limits the amount of arsenic in all waste products to 5 parts per million (ppm).
Barium is a highly reactive metal found in many manufactured products, including rat poison, fireworks, fluorescent light bulbs, and floor tiles. The EPA’s regulation stipulates that there can be no more than 100 ppm of barium in waste.
Barium, one of the RCRA 8 metals, used in fireworks
Barium is used in the coloring of fireworks

Cadmium is blue-grey soft metal. It is a byproduct of copper and zinc production. Shellfish, mushrooms, dried seaweed, mussels, and cocoa powder are also naturally rich in the toxic metal. Cadmium can be ingested by humans through contact with secondhand smoke. It can cause harm to the kidneys and liver. Its regulated level is 1 ppm.
Chromium is a steel-grey-colored, brittle metal most often used, as you might expect, in chrome electroplating. But its earliest use can be dated back to the Qin Dynasty in China, where chromium oxide coated the weapons of the funereal Terracotta Army. Trace amounts of the metal are necessary for human health, but overexposure to the substance inside the body can lead to liver, kidney, and blood stream damage. The EPA regulates chromium at 5 ppm.
Lead’s health hazards are well-documented, yet is still found in many things, including crafted metals, ammunition, old paints, and batteries. A naturally-occurring substance, lead is released into the atmosphere or leaches into water supplies during the burning of fossil fuels and certain manufacturing processes. Exposure to lead can cause lead poisoning, which has been shown to be deleterious to the cognitive functionality of the brain, and also a possible cancer-causing agent. The regulated level of lead is 5 ppm.
Mercury, or quicksilver, is a silvery, liquid heavy metal. It can be found in glass thermometers, batteries, and even dental fillings. Ingestion of methly-mercury is common in fish consumption, and its buildup can sometimes lead to mercury poisoning. The long-term effects of mercury poisoning are impaired cognition, tremors, and circadian rhythm disturbances. Mercury is regulated by the EPA at 0.2 ppm.
Selenium is a usually found in soil, but is also generated in its elemental state as the byproduct of refining metal sulfide and copper ores. Its uses in manufacturing can range from the production of electronics (as it is a semiconductor) to pharmaceuticals. Selenium is also necessary for human health, and can even be bought as a supplement, as it has antioxidant properties which protect cells from damage. However, too much selenium can lead to selenosis. Its regulation level is 1.0 ppm.
Silver is used in jewelry, coins, dental fillings, mirrors, of course, silverware. Exposure to silver can happen either through inhalation or ingestion. Overexposure to silver can cause argyria, which can turn the skin a blue or grey color and interfere with breathing patterns. The EPA sets a limit of 5 ppm for silver waste.

By being aware of the regulated concentrations of each of the RCRA 8 metals, you will be better suited to dispose of them in an EPA-compliant manner. For example, if the degree of one of these hazardous metals exceeds the allowable limit, the waste must be treated as hazardous.
But if the concentration of the metal is below the limit, the waste can legally be disposed of in a landfill, which is much less expensive.

Testing Hazardous Concentrations in Waste: the Toxicity Characteristic Leaching Procedure

The only way to ascertain the concentration of hazardous compounds inside waste is by testing the waste in a process called the Toxicity Characteristic Leaching Procedure (TCLP). The TCLP is a method used to simulate leaching through a landfill and analyzes the presence and volume of hazardous substances within waste. There are four main features of the TCLP, which include:
  1. Sample preparation for leaching;
  2. Sample leaching;
  3. Preparation of leachate for analysis; and
  4. Leachate analysis
This test will help you better understand whether or not your waste can be land-disposed, or if it must be treated and disposed of as hazardous waste.

Understanding the characteristics and regulation of hazardous wastes is vital—and can mean the difference between compliance and fines.
If you would like to learn more about RCRA regulation, please take a moment to download our free eBook, Hazardous Waste: Basics for the First Time Generator. Or, if you would like to speak to an expert about disposing of RCRA 8 metals waste, give us a call today at 800-936-2311.

Photo credit: Wikimedia Commons

How Much Should You Worry About Asbestos in the Home?

Asbestos was a popular material for most of the twentieth century, mainly because of its ability to insulate and act as a fire retardant. In fact, it's still used heavily in some parts of the world, such as India and China. We know enough about the risks now, though, that it's banned outright in more than 50 countries according to and banned for some uses in the US. But how worried should you be if you find it in your home?

Asbestos in the home

asbestos duct tape health safety risk
One of the places you might find asbestos in a home is the duct system. The white tape you see above is of the type that often contains asbestos, although you don't really know without sending a sample to be tested in a lab. If you have an older home with rigid metal ducts, as shown above, it might have the white fabric tape you see in the photo.
The video below, from the 1920s, shows two workers applying a thick insulation material to the boiler and ducts in the home. (Skip to the 6:20 mark to see that part.) That stuff probably had asbestos in it.
Other places you might find asbestos are:
  • Floor tiles
  • Ceiling tiles
  • Vermiculite insulation in attics and walls
  • Roofing and siding
  • Artificial ashes and embers in gas fireplaces
  • Textured paint and patching compounds (banned in 1977)

What health problems does asbestos cause?

The big three diseases listed on all the asbestos websites are:
  • Asbestosis
  • Mesothelioma
  • Lung cancer
All of them result from asbestos fibers getting into the lungs. Asbestos occurs in six mineral types, and all have fibers that are harmful to lung tissue, getting embedded in lung tissue and causing inflammation, scarring, and eventually tumors. The photo below (from the US Geological Survey) shows the fibers of the Chrysotile type, which makes up about 90% of all the commercially available asbestos.
chrysotile asbestos sem image UICCA 500
Asbestosis is an inflammation leading to shortness of breath, coughing, and other breathing problems. Mesothelioma is a cancer of the protective membrane around the lungs. Lung cancer is well known because so many people succumb to it each year, mostly from smoking. (Both of my parents died of lung cancer; both had been smokers.)
The World Health Organization says asbestos exposure leads to these three diseases killing more than 107,000 people worldwide every year. That's a big number. In addition, many more people die of other asbestos-related diseases or suffer various levels of disability.
The problems with asbestos have been known for a long time. The ancient Persians and Romans used the stuff and may have noticed health problems associated with its use. In 1902, asbestos was added to a list of harmful industrial substances in England. Nellie Kershaw, who worked in a factory spinning asbestos fibers into fabric, was the first officially diagnosed case of asbestosis. She died in 1924. (See Discovery of Toxicity section in Wikipedia article on asbestos.)
The consensus in the medical community is that asbestos is dangerous, which is why it's classified as a known human carcinogen. There's no debate on that point, and the lawyers have had a field day litigating asbestos health problems.

Are you at risk?

If you live in a home built before 1980, there's probably some asbestos in it. The stuff was used in a lot of different building materials. But here's the good news for homeowners. The people who get asbestosis, mesothelioma, and asbestos-related lung cancer are almost always people who fall into one of these groups:
  • Asbestos mine, mill, or transportation workers
  • Asbestos product workers (e.g., shipbuilders, construction workers, pipefitters, auto mechanics)
  • Families of asbestos workers (because of fibers brought home on clothes and in hair)
  • People who live near asbestos mines or mills
Another group being watched because of high asbestos exposure are the people involved in the rescue and cleanup efforts in New York City after the 9/11 attacks in 2001. It'll be a while before we know how bad it really was because it generally takes 10 to 40 years for symptoms to appear.
Asbestos in some form is in millions of homes, but I haven't been able to find statistics on the health effects of asbestos exposure in the home. That doesn't mean they aren't there, but the cases of health problems from occupational exposure dominate. The only mention of health problems from exposure in the home that I could find are related to people living with asbestos workers or living near asbestos mines or mills.
That doesn't mean you have nothing to worry about, but I think the National Cancer Institute's view is one to keep in mind:
Everyone is exposed to asbestos at some time during their life. Low levels of asbestos are present in the air, water, and soil. However, most people do not become ill from their exposure. People who become ill from asbestos are usually those who are exposed to it on a regular basis, most often in a job where they work directly with the material or through substantial environmental contact.
In other words, don't panic.

What should you do about asbestos in the home?

If you do find something in your home that you think may contain asbestos, rule number one is:
Don't mess with it!
If you see white tape on your ducts, as shown in the photo above, vermiculite insulation in your attic, as shown below, it's probably not causing a problem as long as it's undisturbed. (Vermiculite insulation, which may contain the Tremolite types of asbestos, is a big enough topic that I'll write a whole article about it later.) Asbestos isn't like radioactivity, which can be a hazard because it constantly emits radiation. Asbestos only becomes a problem if it becomes airborne and gets into your lungs at a high enough dose.
vermiculite attic insulation asbestos risk
If you're concerned about a particular material in your home, you can call an asbestos inspection company to come in and have the material tested. They'll take samples using the approved protocols and send them to a lab for testing. When you get the results back, the company you hired can help you decide what your next steps should be.
As long as you're not planning to make changes to the home that require disturbing it, it might be best just to leave the material alone. If the suspected asbestos-containing material is friable, encapsulating or enclosing the material can help prevent the fibers from getting into the air. But this's not a job to be taken lightly, so you should hire a pro. The US EPA has a good page for homeowners on what to do if you may have asbestos in your home.

A word to the pros

For those who work in the fields of HVAC, insulation, plumbing, home performance, or remodeling and deal with older homes, you're likely to come across many homes with materials that may contain asbestos. You owe it to yourself and your family to take all the proper precautions when working with these materials.
You may not have the exposure that killed Nellie Kershaw after only seven years of spinning asbestos fibers into fabric. You may not even get enough exposure over a career to cause problems. Still, do you want to take that chance? I can tell you from my experience with asthma as a child that having difficulty breathing is no fun at all. And from seeing both of my parents die of lung cancer, I can tell you that's not a nice way to go.
If you spend a lot of time in the attics, basements, and crawl spaces of older homes, don't mess around with materials that may be dangerous. Whether you're an employer or employee, check out the OSHA page on asbestos and be safe.


We humans are a curious and ambitious lot, always striving to understand the world around us and improve our circumstances. If a material exists anywhere near the surface of the Earth, we've found it and exploited it for its useful properties. Like the toddler touching the hot stove, though, we often don't discover the harmful properties until after the damage is done. That is also true of asbestos.
The stuff is out in the world now, and we must deal with it. The key is to use caution and know what you're dealing with.

HVAC boot cleared of Asbestos in Los Angeles