Cathode Ray Tube (CRT)
A cathode ray tube (CRT) is the glass tube that converts an electronic signal into a visual image on a television or computer. Most desktop computer displays and older televisions use CRTs. Cathode ray tubes are toxic because of phosphor, which contains several toxic metals, and because of the high lead content in the glass of the cone part of the CRT.
Arsenic is often found in circuit boards where it is used as a conductor. Electronics contain low levels of the element, but if it is allowed to accumulate in dumps or landfills, it can be a serious threat to health.
Barium is a metallic element that is chemically similar to calcium but more reactive. Found in sparkplugs and fluorescent lamps, it is highly unstable in the pure form and it becomes poisonous when it comes in contact with air. Short-term exposure to Barium can lead to brain swelling, muscle weakness, damage to the heart, liver, and spleen.
Beryllium is a naturally occurring element found in soil. It's used in electronics to produce springs and connections. Beryllium dust is toxic to humans, and exposure to it can cause lung cancer and respiratory problems.
Brominated flame retardants (BFRs)
BFRS are used in electronic and electrical appliances to make materials more flame resistant. They have been found in indoor dust and air through migration and evaporation from plastics. Combustion of halogenated case material and printed wiring boards at lower temperatures releases toxic emissions including dioxins which can lead to severe hormonal disorders. Major electronic manufacturers have begun to phase out brominated flame retardants because of their toxicity.
Cadmium is used in contacts and switches, rechargeable batteries and cathode-ray tubes. Cadmium is highly toxic to plants, fish and humans. Inhalation has been linked to lung cancer.
Chlorofluorocarbons are compounds composed of carbon, fluorine, chlorine, and sometimes hydrogen. Used mainly in cooling units and insulation foam, they have been phased out because when released into the atmosphere, they accumulate in the stratosphere and deteriorate the ozone layer. Exposure results in increased incidence of skin cancer in humans and in genetic damage in many organisms.
Chromium and its oxides are widely used because of their high conductivity and anti corrosive properties. While some forms of chromium are non-toxic, most compounds are irritating to eyes, skin, and mucous membranes. Chronic exposure can cause permanent eye injury, unless properly treated, and can also cause DNA damage.
The degree to which a substance dissolves materials and living tissues by chemical action. Examples of corrosive substances are drain openers and oven cleaners.
Dioxins and furans are a family of chemicals comprising 75 different types of dioxin compounds and 135 related compounds known as furans. Dioxins have never been intentionally manufactured, but form as by-products in the manufacture of substances such as pesticides and in combustion processes. Dioxins are known to be highly toxic to animals and humans because they accumulate in the body and can lead to deformities of the fetus, decreased reproduction and growth rates, and cause impairment of the immune system.
The degree to which a substance can pose a fire hazard. Examples of ignitable wastes include:
- flammable liquids (flash point less than 60oC)
- solids that can start burning through friction or absorption of moisture
- certain compressed gases
Lead is the fifth most widely used metal - it is commonly used in the electronics industry in lead-acid batteries, electronic components, cable sheathing and the glass of CRTs. It is toxic to humans and is particularly dangerous for young children because it can damage nervous systems and cause blood and brain disorders.
Mercury is one of the most toxic yet widely used metals in the production of electronic appliances, appearing in batteries, some switches and thermostats, and fluorescent lamps. It is a toxic heavy metal that bio-accumulates causing brain and liver damage if ingested or inhaled.
Polychlorinated biphenyls (PCBs)
Polychlorinated biphenyls (PCBs) are a class of organic compounds used in a variety of applications, including dielectric fluids for capacitors and transformers, heat transfer fluids and as additives in adhesives and plastics. PCBs have been shown to cause cancer in animals and a number of serious health effects, including affecting the immune system, reproductive system, nervous system, and endocrine system. Due to the high lipid solubility and slow metabolism rate of these chemicals, PCBs accumulate in the fat-rich tissues of almost all organisms (bioaccumulation) and are persistent in the environment. the use of PCBs is prohibited in OECD countries. However, due to its wide use in the past, it can still be found in electrical waste.
Polyvinyl chloride (PVC)
Polyvinyl chloride (PVC) is the most widely-used plastic, contained in electronics and appliances, household items, pipes, upholstery etc. PVC is hazardous because contains up to 56 % chlorine which when burned produces large quantities of hydrogen chloride gas that forms hydrochloric acid which is dangerous because when inhaled, it leads to respiratory problems.
A waste is reactive if it is likely to explode, react violently, or release toxic gases if it comes in contact with water. One example of a reactive substance is nitroglycerin.
Exposure to high concentrations of selenium compounds cause selenosis, symptoms of which include hair loss, nail brittleness, and neurological abnormalities (such as numbness and other odd sensations in the extremities).
The degree to which a substance can harm humans or animals. Toxicity can be acute, sub-chronic, or chronic:
- Acute toxicity involves harmful effects in an organism through a single or short-term exposure.
- Sub-chronic toxicity is the ability of a toxic substance to cause effects for more than one year but less than the lifetime of the exposed organism.
- Chronic toxicity is the ability of a substance or mixture of substances to cause harmful effects over an extended period, usually with repeated or continuous exposure, sometimes lasting for the entire life of the exposed organism.