Which Substances Make Up the RCRA 8 Metals

Which Substances Make Up the RCRA 8 Metals

Many people may not be aware of the Resource Recovery and Conservation Act’s (RCRA) specific list of a group of eight heavy metals. This list is commonly referred to as the RCRA 8. Many may wonder, what is the purpose of a list of these 8 specific metals? The main purpose is that these eight metals are among the most dangerous and toxic when kept in small concentrations. What can be more concerning is that many of these metals can appear in waste. For this reason, there must be regulations that govern the acceptable amount of each metal in waste.

Many of these metals are found in waste materials that we use in our own homes, including batteries and light bulbs. Any of these waste materials must be disposed of in specific ways according to strict federal and state regulations. But what exactly makes each of these metals so hazardous? In order to better understand this, it is important to investigate the makeup of every individual metal. Learn more here, as we further investigate which substances make up the RCRA 8 metals.


This particular metal may sound very familiar. This is likely because, for the last several hundred years, arsenic has been known as a notorious poison. It may be surprising to some, but arsenic can be found in trace amounts in some types of food and water. It even appears in tobacco smoke. Rest assured, these levels are usually harmless. Although people generally view it as a poison, arsenic has had other uses throughout history.

One prominent use is to strengthen alloys such as lead and copper. Arsenic’s toxicity also makes it beneficial in fighting fungus, bacteria, and insects for wood preservation. The FDA even approved it as a treatment for some forms of leukemia in 2000. As arsenic is usually very hazardous, the EPA limits its amount in all waste to 5 parts per million. Any waste that could contain larger amounts of arsenic is considered hazardous waste.


This silvery-white metal also exists naturally in our environment. Barium can oxidize very easily, which causes it to have a high level of reactivity, specifically with elements such as oxygen. People that are most at risk of exposure are those who work in industries that make or use barium compounds, such as the gas and oil industries. Small amounts of barium can be found at times in food and drinking water, although they are usually not high enough to become a health concern.

Barium poisoning typically occurs through breathing air that contains barium sulphate or barium carbonate. Common products that contain barium include rat poison, fireworks, fluorescent light bulbs, and floor tiles. You should look into proper hazardous waste disposal services when discarding any of these items, as they are unacceptable for normal dumpster or waste disposal.


Cadmium is a byproduct of copper and zinc production. It is a soft metal with a blue-grey color. Cadmium has been known to appear in certain types of paint, especially those sold in some foreign countries. In the past, certain products such as plastic cups have been recalled because they used these paints. Long-term exposure to cadmium, even at low levels, can eventually cause cancer and target the body’s cardiovascular, neurological, reproductive, and respiratory systems. Batteries are one of the most common household products to contain cadmium.


When wondering which substances make up the RCRA 8 metals, this is one most people will certainly recognize. This metal is commonly used in chrome electroplating. One of the earliest uses for chromium was for coating weapons during the Qin Dynasty in China. This metal is a bit different from several others on this list because, in trace amounts, chromium is necessary for our health. Only when there is overexposure does chromium become a hazard. High amounts of chromium can lead to damage in the liver, kidneys, and bloodstream. For this reason, the EPA regulates it at 5 parts per million.


The health hazards of lead have been extremely well documented over the course of history. It is still commonly found in many items, such as crafted metals, ammunition, old paints, and batteries. Lead is another naturally occurring substance. It typically gets into the atmosphere through a water supply during the process of burning off fossil fuels, but it can happen through other manufacturing processes as well.

This has made the fossil fuel industry a great concern to the environment. Overexposure can cause what is infamously known as lead poisoning. This condition has affected many people throughout human history, and typical symptoms include worsening cognitive function and, in more serious cases, cancer.


One of the most dangerous metals on this list is mercury, as it is a liquid-heavy metal. One of the reasons mercury is so concerning is that its presence is quite common. Common products that contain this metal include glass thermometers, batteries, and even dental fillings. Another concern is that many species of fish contain high levels of mercury. Scientists recommend that people limit the amount of seafood they consume, as long-term effects can lead to mercury poisoning, which results in impaired cognition, tremors, and disruption to the circadian rhythm.


Selenium is generally found in soil, but it can also come as a byproduct of refining metal sulfide and copper ores. Selenium is commonly used to manufacture electronics and pharmaceuticals. This is another metal that is good for human health, but it can become very toxic in trace amounts. The worst levels of exposure can result in selenosis. For this reason, you must discard any electronics that contain selenium in the proper manner.


One final metal, which will be probably the most recognized on our list, is silver. While silver is used in many products, including jewelry, coins, dental fillings, mirrors, and silverware, certain types of exposure can be very dangerous. The most common cause of overexposure to silver is through either inhalation or ingestion. Overexposure can cause argyria, which can disrupt breathing and turn the skin blue or grey.

RCRA 8 Metals

I am looking for: