RoHS Substances Explained

While there are sometimes heated discussions about the economic impact of environmental laws, it might be helpful to summarize what the six current EU (and China) RoHS materials are, where they are commonly used, and some of their less than desirable effects on humans:


Lead is a heavy metal that occurs naturally in the environment and is produced from man-made sources. Most exposures to lead come from lead paint and emissions from industrial facilities like metal smelters. Other sources of exposure include crystal tableware, porcelain enamel and contaminated food. Lead is a suspected carcinogen, a known hormone disruptor, and can damage almost every organ and system in the human body, particularly the nervous system. Lead has been indicated as a cause of decreased mental ability, developmental delays, behavioral disorders and reproductive defects.

Lead is/was commonly used in the electrical and electronics industry in solder, lead-acid batteries, electronic components, cable sheathing, in the glass of CRTs etc. Short-term exposure to high levels of lead can cause vomiting, diarrhea, convulsions, coma or even death. Other symptoms are appetite loss, abdominal pain, constipation, fatigue, sleeplessness, irritability and headache. Continued excessive exposure, as in an industrial setting, can affect the kidneys. It is particularly dangerous for young children because it can damage nervous connections and cause blood and brain disorders


When inorganic mercury enters the air from these human sources it is then deposited in soil and water, where micro organisms transform inorganic mercury into organic mercury compounds, such as methyl mercury. Methyl mercury can bioaccumulate in the fatty tissues of living organisms, particularly fish living in polluted waters, and the people who then eat those fish. Mercury is a recognized developmental toxin, and it is also a suspected hormone disruptor, neurotoxin, reproductive toxin and respiratory toxin.

Mercury is one of the most toxic yet widely used metals in the production of electrical and electronic applications. It is a toxic heavy metal that bioaccumulates causing brain and liver damage if ingested or inhaled. In electronics and electrical appliances, mercury is highly concentrated in batteries, some switches and thermostats, and fluorescent lamps.


Cadmium is a heavy metal that comes from both natural and man-made sources. Most exposures to cadmium come from pigments and bake ware, as well as electronic equipment, car parts, batteries, phosphate fertilizer, sludge applications in agriculture and contaminated food. This heavy metal is known to cause lung and prostate cancer, and is toxic to the gastrointestinal tract, the kidneys, and the respiratory, cardiovascular and hormonal systems. Cadmium components may have serious impacts on the kidneys. Cadmium is adsorbed through respiration but is also taken up with food.

Due to the long half-life in the body, cadmium can easily be accumulated in amounts that cause symptoms of poisoning. Cadmium shows a danger of cumulative effects in the environment due to its acute and chronic toxicity. Acute exposure to cadmium fumes causes flu-like symptoms of weakness, fever, headache, chills, sweating and muscular pain. The primary health risks of long term exposure are lung cancer and kidney damage. Cadmium also is believed to cause pulmonary emphysema and bone disease (osteomalacia and osteoporosis).


Chromium and its oxides are widely used because of their high conductivity and anti corrosive properties. While some forms of chromium are non toxic, Chromium (VI) is easily absorbed in the human body and can produce various toxic effects within cells. Most chromium (VI) compounds are irritating to eyes, skin and mucous membranes. Chronic exposure to chromium (VI) compounds can cause permanent eye injury, unless properly treated. Chromium VI may also cause DNA damage.

Brominated flame retardants (PBB, PBDE)

The 3 important types of BFRs which can / could be used in electronic and electrical appliances are Polybrominated biphenyl (PBB), Polybrominated diphenyl ether (PBDE) and Tetrabromobisphenol-A (TBBPA). Flame retardants make materials, especially plastics and textiles, 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.

PBDEs are highly persistent and bioaccumulative and they are suspected hormone disruptors and can cause cancer reproductive and developmental disorders. PBDEs are suspected of having particularly damaging effects on the thyroid (which controls brain development), and as a result, PBDEs may cause neurodevelopmental disorders such as learning disabilities and behavior problems. PBDEs leach from products, and have been detected in house dust, human blood and breast milk.

Phthalates (DEHP, BBP, DBP, DIBP)

Added as part of DIRECTIVE (EU) 2015/863 which was published on 31 March 2015, this restriction takes effect on 22 July 2019 except for Category 8 Medical Devices and Category 9 Monitoring & Control Instruments, which takes effect 22 July 2021. Bis (2- ethylhexyl) phthalate (DEHP), Butyl benzyl phthalate (BBP), Dibutyl phthalate (DBP) and Diisobutyl phthalate (DiBP) are usually found in plasticizers in PVC, rubber or other polymers (cable/wire/tubing), in sealants and adhesives, in flexible varnish/paint/coating/ink and certain glass.

Phthalates have been demonstrated to cause endocrine disruption; children are considered to be particularly vulnerable to negative health effects.

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