What hazardous materials are in common electronics

Common electronics contain a range of hazardous materials that can be harmful to health and the environment if the devices are just dumped in ordinary waste. When screens are smashed, batteries leak, or cables are burned, these substances can enter soil, water, and air, exposing people and ecosystems to serious risks. Below are the main hazardous materials you are likely to find in everyday electronics.

Heavy metals

Several toxic metals are embedded in electronics for specific technical functions:

• Lead (Pb): Found in older CRT monitors and TVs, solder on circuit boards, and some batteries. Lead is a neurotoxin that can damage the brain and nervous system, especially in children, and does not break down in the environment.

• Mercury (Hg): present in fluorescent backlights of some LCD screens, compact fluorescent lamps, and certain switches. Mercury vapor is highly toxic, affecting the nervous and respiratory systems and accumulating in fish and other food chains.

• Cadmium (Cd): used in rechargeable NiCd batteries, older CRT screens, and some older semiconductors. It can damage kidneys and bones and is classified as a carcinogen.

• Hexavalent chromium: used in metal plating for corrosion resistance on some internal parts. It is a strong irritant and carcinogen when inhaled or ingested.

• Arsenic, beryllium, and nickel: occur in small amounts in semiconductors, LEDs, rechargeable NiCd or NiMH batteries, and power‑supply components. These can cause respiratory disease, skin problems, and, in some cases, cancer when inhaled as dust or fumes.

Flame retardants and plastics

Electronics use certain chemicals to reduce fire risk, but these can be environmentally persistent and toxic:

• Brominated flame retardants (BFRs) and halogenated flame retardants are added to plastic casings, circuit boards, and cable insulation. Some types are persistent in the environment and can interfere with hormones and nervous‑system development.

• Polyvinyl chloride (PVC) is common in cables, power cords, and plastic parts. If PVC is burned, it releases dioxins and other toxic fumes; if left in landfill, plastic waste can still leach additives over time.

• Phthalates and other plasticisers are sometimes added to make plastics more flexible. These can migrate out of the material and are suspected endocrine disruptors.

Other hazardous components

Beyond metals and plastics, other dangerous substances are also present:

• Lithium and other reactive battery materials: rechargeable lithium‑ion batteries power phones, laptops, and many gadgets. If damaged or improperly disposed of, they can leak chemicals or even catch fire or explode.

• Rare earth elements and mixed metals: elements like yttrium, europium, and selenium occur in LED and CRT screens and fluorescent coatings. While not always toxic in themselves, their recovery and disposal in uncontrolled settings can release associated metals and dust.

Because of these hazardous materials, it is important that old phones, TVs, laptops, and other electronics are not thrown in the regular bin but instead taken to licensed e‑waste handlers or certified recycling centres. Proper recycling ensures that these dangerous substances are safely contained while useful metals, glass, and plastics are recovered and reused.