Mercury and health
Mercury is considered by World Health Organisation as one of the top ten chemicals or groups of chemicals of major public health concern. It may have toxic effects on the nervous, digestive and immune systems, and on lungs, kidneys, skin and eyes and exposure – even to small amounts – may cause serious health problems[1].
When you breathe in mercury vapours, most (about 80%) of the mercury enters your bloodstream directly from your lungs, and then rapidly goes to other parts of your body, including the brain and kidneys[2].
Exposures of concentrations between 15 g/m3 and 30 g/m3 during long periods of time have shown negative effects on the human health. Exposure of mercury vapours with a concentration between 1 mg/m3 and 3 mg/m3 during a few hours may cause pulmonary irritation and destruction of the tissues in the lungs, and occasionally disorders in the central nervous system[3].
Mercury in Flat Panel Displays
Certain FPDs contain mercury within the CCFL (Compact Cathode Fluorescent Lights) backlights.
The amount of mercury in CCFLs varies between 0.1 mg/lamp and 10 mg/lamp and the number of CCFLs in LCD TVs differs between 2 and 28 lamps, depending on the size and design of the TVs[4].
Presence of mercury in flat panel displays poses a significant problem for electronic equipment recyclers, as it has the potential for release of mercury vapour and powder containing mercury – one of the most hazardous substances known.
Mercury has not only been found in vapours from fluorescent lamps; it has also been found in the electrodes, in the glass[5] and in the fluorescent powder.
How are people exposed in recycling facilities?
When CCFL glass tubes are damaged they create direct exposure to mercury vapour and mercury powder, which poses a high risk to humans and the environment.
Traditionally recycling of flat screens containing CCFLs was done through either shredding or manual disassembly. During such processes the environment and the workers are at risk of being exposed to mercury, if strict precautions are not taken.
Broken backlights reach a share of about 20% for TV’s and less than 5% for PC monitors in manual disassembly process[6].
Legislation & best practice
Processing FPD carries many health & environmental risks and hazards, therefore requires strict controls and restrictions – some of them defined by legislation and many more voluntarily implemented with standards and certifications for increased protection of staff and environment.
The end-of-life treatment facilities should not only be equipped with ventilation systems which remove mercury vapours, but precautions needs to be taken around handling and containing CCFL glass tubes.
Recyclers shall establish operational controls for processing e-waste to safely remove, separate, and prevent mechanical processing (de-pollution) of mercury-containing components (including mercury lamps, older LCD screens, switches, some batteries) unless using a closed-system processing technology specifically designed to effectively control any potentially hazardous releases and/or exposure.
Any Electronic Equipment (including circuit boards, lamps, switches, assemblies, housings, plastics, cables, and wires) that contains mercury as intentional inputs, in unknown levels, or in levels exceeding 0.2 mg/L threshold limit is considered Hazardous Electronic Waste/Hazardous e-Waste (HEW)[7].
Work environment levels for mercury (Hg) vapours work environmental levels of mercury allowed, over a period of eight hours, five days a week[8]:
| Country | Organic Hg | Non-organic Hg |
| Sweden | 0.01 mg/m3 | 0.03 mg/m3 |
| Taiwan | 0.01 mg/m3 | – |
| Germany | 0.02 mg/m3 | 0.02 mg/m3 |
| UK | 0.02 mg/m3 | 0.02 mg/m3 |
| Japan | 0.025 mg/m3 | – |
FPD PRO® Mercury Safety Measures
Full enclosure
FPD PRO® closed design allows to effectively control any potentially hazardous releases and/or exposure.
This way mercury vapours are released and captured within a closed and controlled environment and hazardous materials are sealed before leaving the machine – minimising the risk of exposure to workers and ensuring better quality of materials recovered.
Filtration system
FPD PRO® is equipped with The Donaldson Torit® DCE® cartridge collectors with high-efficiency nanofiber Ultra-Web® filters, engineered to capture the broad spectrum of dust particles and last long.
Air nozzles
FPD PRO® is equipped in high-efficiency air sucking nozzles – at each exit and inside the container.
CCFL tubes crusher
Because CCFL backlight tubes, made from a thin glass, are very fragile – rather than trying to prevent breakage (in effort to contain hazards within the tubes), FPD PRO® is designed to break and crush them intentionally.
Crushed CCFL tubes are contained within FPD PRO® and leave in sealed containers.
Controller systems
Electrical controller systems to automate processes like pressure drop measurement and control.
Additional monitoring equipment
FPD PRO® is ready for installing optional mercury Occupational Exposure Limit (OEL) monitoring equipment, if requested by customer.
Mercury monitoring results for FPD PRO®
Independent emissions monitoring of Exhaust Silencer Outlet carried out on FPD PRO® showed average concentration of mercury at 0.001 mg/m³. Please contact us for detailed test results.
References:
[1] WHO (https://www.who.int/news-room/fact-sheets/detail/mercury-and-health)
[2] ATSDR (https://www.atsdr.cdc.gov/sites/toxzine/mercury_toxzine.html)
[3] World Health Organisation (2000) Air Quality Guidelines for Europe, Second edition, WHO Regional Publications, European Series, No. 91 and Evaporation of Mercury from CCFLs during Recycling of LCD Television Sets K.Elo, E. Sundin
[4] Evaporation of Mercury from CCFLs during Recycling of LCD Television Sets, K.Elo, E. Sundin
https://www.diva-portal.org/smash/get/diva2:680230/FULLTEXT01.pdf
[5] Thaler, E. G., Wilson, R. H., Dought, D. A., Beer, W. W. (1995) Measurement of mercury bound in the glass envelope during operation of fluorescent lamps, Journal of the Electrochemical Society, 142, 6, pp 1968-1970.
[6] Disposal of Flat Panel Display Monitors in Switzerland Final Report March 2011, p.5
[7] The e-Stewards® Standard for Ethical and Responsible Reuse, Recycling, and Disposition of Electronic Equipment and Information Technology
[8] Evaporation of Mercury from CCFLs during Recycling of LCD Television Sets, K.Elo, E. Sundin
https://www.diva-portal.org/smash/get/diva2:680230/FULLTEXT01.pdf
