WEEE depollution: Guide to hazardous substance management

Depollution — the removal of hazardous components and substances before mechanical treatment — is the most critical stage in the WEEE recycling process. Incomplete depollution contaminates output fractions, exposes workers to serious health risks, and can attract sanctions up to and including suspension of the environmental permit. This guide covers the major hazardous substances found in WEEE, with concrete handling protocols.

Mercury: the most underestimated risk

Mercury is present in fluorescent lamps, high-intensity discharge lamps, LCD screens (CCFL backlight lamps), thermostats, relays, and certain switches. Content varies from 3-5 mg per compact fluorescent lamp to 20-30 mg per T8 tubular lamp.

Handling protocol

• Mercury-containing lamps are depolluted exclusively in controlled crushing installations equipped with activated carbon filtration systems, or in end-cap cutting machines that capture mercury vapours
• Storage is carried out in sealed containers, labelled in accordance with ADR, on an impermeable surface with a retention kerb
• Monitoring: the mercury concentration in the air within the work area must be kept below 0.02 mg/m³ (8-hour occupational exposure limit value per GD 1218/2006)
• Mandatory PPE: nitrile gloves, mercury vapour filter mask (type AX or Hg), safety goggles

A frequently overlooked detail: LCD screens manufactured before 2012 often contain CCFL lamps with mercury. Disassembly must include the careful extraction of these lamps before any mechanical operation on the panel.

PCBs (polychlorinated biphenyls)

Although PCB production has been banned globally under the Stockholm Convention, PCB-containing capacitors are still found in old equipment — particularly in lighting fixtures with electromagnetic ballasts manufactured before 1986, in small transformers from old radio and TV sets, and in certain motor start capacitors.

Identification and separation

• Suspect capacitors are identified visually: cylindrical metal casing, no ”PCB-free” marking, diameter over 25 mm
• Precautionary rule: any capacitor from equipment manufactured before 1986 with a capacity exceeding 1 µF is treated as potentially PCB-contaminated until proven otherwise
• Extracted capacitors are collected separately in sealed metal containers, on retention trays
• Disposal is carried out exclusively through incineration at temperatures above 1,200°C in authorised facilities (in Romania, domestic capacity is limited — most are exported)

Asbestos and asbestos-containing materials

Asbestos appears in WEEE more frequently than one might expect: thermal insulation boards in old ovens and dryers, gaskets in industrial heating equipment, and protective boards in old electrical panels. Identification is difficult without experience — chrysotile asbestos materials look similar to pressed cardboard.

Strict protocol

• Any suspect material is treated as asbestos until analytical confirmation (polarised light microscopy or SEM-EDS)
• Handling is carried out exclusively by trained personnel, wearing an FFP3 mask with valve, disposable type 5/6 coverall, and double gloves
• The material is moistened before extraction to reduce the release of fibres into the air
• Storage: in double polyethylene bags, labelled with the asbestos hazard symbol, in a dedicated area
• Disposal: exclusively at landfills authorised for asbestos-containing hazardous waste

CFC, HCFC, and HFC gases from cooling equipment

Refrigerators, freezers, air conditioning units, and dehumidifiers contain refrigerant gases that are either ozone-depleting substances (CFC-12, HCFC-22) or potent greenhouse gases (HFC-134a, R-600a). In addition, the insulation foam in old refrigerators contains CFC-11 as a blowing agent — the amount of CFC in the foam can be 3-4 times greater than that in the refrigeration circuit.

Treatment requirements

• Stage 1 — refrigerant gas extraction: vacuum pumping of the refrigeration circuit with capture in approved cylinders, minimum capture efficiency: 90% per EN 50625-2-3
• Stage 2 — compressor oil extraction: the oil contains dissolved gases and must be collected separately (20-300 ml per appliance)
• Stage 3 — foam treatment: shredding in a controlled atmosphere (nitrogen) with capture of gases released from the foam, minimum blowing agent capture efficiency: 90%
• Monitoring: leak sensors in the work area, mechanical ventilation, portable gas detector for personnel in the treatment hall

Batteries — the fire risk

Lithium-ion batteries found in phones, laptops, tablets, electric scooters, and robot vacuum cleaners represent the most acute current operational risk. A battery that is mechanically damaged or exposed to high temperatures can enter thermal runaway — a self-sustaining exothermic reaction reaching 600-800°C that releases toxic flammable gases.

• Golden rule: batteries are removed manually, before any mechanical treatment, without puncturing the cells
• Storage: in metal containers with sand or vermiculite, away from combustible materials, with fire alarm signalling
• Damaged or swollen batteries are isolated immediately in individual containers and transported as a priority to an authorised recycler

Depollution documentation

Each depollution operation must be documented. The minimum records required under WEEELABEX and EN 50625-1 include:

• Type and quantity of hazardous substance removed (kg or units)
• Destination and waste code (per GD 856/2002)
• ADR transport document or accompanying form
• Certificate of disposal/recovery from the receiving facility
• Occupational exposure register (for mercury and asbestos)

Depollution is the maturity test of a WEEE treatment operator. An operator that bypasses this stage is not recycling — it is merely transferring pollution from one place to another. Investment in depollution equipment and staff training is not a cost, but a condition of operation.