The importance of RoHS Directive: how restricted substances can affect the workers and consumers health
With the ever-growing industrial development, lots of natural or synthetic substances are constantly introduced in the manufacturing of various products. Some of these substances can constitute a workplace hazard or a hazard to the consumer.
For this reason, it was introduced the so called “RoHS Directive”, where “RoHS” stands for “Restriction of the use of Hazardous Substances”. It limits the use of certain hazardous substances in electrical and electronic equipment.
RoHS Directive indicates when the same directive is applicable. In case of applicability, the compliance to RoHS Directive:
- is mandatory for CE Marking,
- must be accomplished by manufacturer in a proper way (e.g.: by product control and testing),
- and must be indicated by law in the EU Declaration of Conformity of the product.
With the latest modifications of the RoHS regulation, the number of these restricted substances (some of which are actually “classes of substances”) is ten, and they are precisely: lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB), polybrominated diphenyl ethers (PBDE), bis(2-ethylhexyl) phthalate (DEHP), butyl benzyl phthalate (BBP), dibutyl phthalate (DBP) and diisobutyl phthalate (DIBP).
Staying within safety limits of use of these substances in various products is of the utmost importance to avoid such health hazards. It is also necessary to use the appropriate protective equipment in workplaces, and to dispose properly of factory wastes in order to prevent environmental contamination.
To better understand the importance for manufacturers to follow the RoHS Directive, and for consumers to buy RoHS compliant products, where applicable, let see where these restricted substances can be found, how they can enter the human body, and how they affect a person’s health.
Lead
Lead-based paints are a major source of lead despite being banned in any countries. Lead fumes from battery manufacturing, metal smelting or some factories are other sources. Lead plumbing lines can contaminate water. Common household electronics containing lead include computers, keyboards, computer mice, mobile phones, smoker alarms, remote controls and cathode ray tubes that are found (nowadays more rarely) inside computer or TV screens. Within each device, it is found in very small amounts. Collectively, however, electronic waste (WEEE) can contain a hazardous amount of lead.
Lead can enter the human body usually through inhalation of lead fumes. In addition, electronic waste can contaminate the soil or water if not recycled or disposed of properly.
Lead is stored in bones, blood and tissues and acts as a source for continuous exposure. Exposure to a significant amount of lead over a short period of time can cause lead toxicity, manifested by abdominal pain, constipation, headache, irritability, loss of appetite, memory loss, pain or tingling in the hands and/or feet and generalized weakness. High levels of exposure can cause anaemia, kidney or brain damage and even death. Pregnant women can transmit lead to their babies which would affect the development of their nervous system, or cause miscarriage or stillbirth.
A person who is exposed to lead over a long period of time may suffer from: abdominal pain, constipation, depression, distraction, forgetfulness, irritability, and nausea. People with prolonged exposure to lead may also be at risk for high blood pressure, heart disease, kidney disease, and reduced fertility. Children are more prone to lead toxicity and can suffer from intellectual disability and neurological problems.
Mercury
Mercury is a toxic metal that can be found in thermometers, barometers, and fluorescent light bulbs. Mercury is sometimes used in dental fillings. Some forms of mercury occur naturally. Methylmercury, one of the forms of mercury, can contaminate the soil or water. It can then be ingested by fish and is stored inside their bodies. It can contaminate both fresh and salty water fish.
Metallic mercury can be inhaled and is extremely toxic. A few drops can generate enough fumes to contaminate a room. The metal can also be absorbed through the skin. Methylmercury can enter the human body through the consumption of contaminated fish.
Mercury poisoning can manifest as impairment of coordinated movements such as walking or writing, impairment of speech, hearing or vision, emotional instability, memory loss, insomnia, muscle weakness, numbness of the hands or feet and skin rashes. High levels of exposure can affect the central nervous system, the kidneys, the reproductive system, and the immune system. It can also cause high blood pressure and increase the risk of heart attacks. Mercury crosses the placental barrier and interferes with the normal development of the foetus. Children exposed to mercury can have developmental delays and attention deficit.
Cadmium
Cadmium is present in tobacco leaves which accumulates it from the soil. It is also a byproduct that is extracted during the production of zinc, lead, and copper. In addition, it is used in the production of batteries, pigments, electroplating, solar cells, and plastic stabilizers. It can contaminate air, soil or water during the manufacturing of the previously-mentioned products, and it can accumulate in aquatic organisms and agricultural crops.
Smoking and ingestion of cadmium-contaminated crops are the two major ways to enter the human body. The consumption of water contaminated from factory wastes can be another source. Occupational exposure includes the inhalation of fumes or the ingestion of cadmium from contaminated hands or food. Cadmium cannot be absorbed through the skin. Cadmium accumulates in the kidneys and the liver; with chronic exposure it can cause kidney damage and bone fragility.
Ingestion of cadmium can cause stomach irritation while the inhalation of cadmium fumes causes damage to the lungs and can cause lung cancer. It is secreted in breast milk and can therefore be transmitted to breastfed children. Its effect on children is presumed to be similar to adults. The effects of cadmium on pregnancy in humans are uncertain.
Hexavalent chromium
Chromium occurs in nature in combination with other elements in rocks, animals, plants, and soil. It has three main forms: chromium 0, chromium III and chromium VI. Of these, the hexavalent form is the most toxic to humans. It is used in the manufacturing of metal alloys such as stainless steel. It is commercially present in some types of wood, leather, stainless steel and hip prosthesis.
The main route is through inhalation, either as a workplace exposure or the inhalation of contaminated air from the wastes of facilities that use it. Chromium can also contaminate water and the soil. It can enter the body through ingestion or through the skin while bathing in contaminated water. Trace amounts can be found in some foods such as fruits, vegetables, nuts and meat.
Chromium mainly affects the respiratory system through inhalation. It can cause nasal irritation, cough, asthma, difficulty in breathing and, with occupational exposure, lung cancer. Its effects on children are probably the same as adults. No studies have shown that it causes birth defects in humans.
Polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs)
Polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) are synthetic products that were added to plastic to make it more difficult to burn. Most of them are no longer produced in Europe. However, due to their very slow degradation, they can still be present in the environment.
PBBs can contaminate air, soil, water and fish or other marine animals. They can enter the body through ingestion, inhalation or dermal contact.
These substances tend to accumulate in the adipose tissue and their main effect is causing disturbances of the endocrine system. Experiments on mice have also shown that these substances can cause neurotoxicity, skin disorders, liver toxicity, kidney toxicity, immunotoxicity, diabetes and cancer.
Di (2-ethylhexyl) phthalate (DEHP)
DEHP is a synthetic substance that is added to plastic to make it more flexible. It is used in the manufacturing of wall coverings, tablecloths, floor tiles, shower curtains, garden hoses, swimming pool liners, rainwear, baby pants, dolls, some toys, shoes, packaging film and sheets, sheathing for wires and cables, medical tubing, and blood storage bags.
DEHP can be transferred to humans through the inhalation of contaminated dust, through the ingestion of contaminated food or undergoing medical procedures using medical equipment containing DEHP.
Exposure to DEHP above the safe levels can cause cancer and damage to the male reproductive system. In pregnant women, it can affect the development of the baby.
Dibutyl phthalate (DBP) and diisobutyl phthalate (DIBP)
They are synthetic substances that are added to plastic to make it more flexible and are also used in carpet backings, paints, glue, insect repellents, hair spray, nail polish, and rocket fuel. They can enter the human body through inhalation or through the skin. Acute exposure can cause irritation to the skin, eyes, nose, and throat as well as headache, nausea, dizziness, and seizures. Chronic exposure is potentially carcinogenic. They can also damage the male reproductive system and can affect the development of the foetus in pregnant women.
Butyl benzyl phthalate (BBP)
Butyl benzyl phthalate (BBP) is a synthetic substance that is added to plastic to make it more flexible. It is used in the manufacturing of some vinyl flooring, paints, handbags, belts and footwear. BBP can be transferred to humans through the inhalation of contaminated dust or through ingestion from contaminated hands. Exposure to high levels of BBP can cause damage to the reproductive system. In pregnant women, it can affect the development of the baby.
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- identification of the obligations for your specific products
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