by SENS and SWICO - Ecotic

PCB’s in Small Capacitors from Waste Electrical and Electronic Equipments1 Initial Situation and Target1.1 Capacitors and EnvironmentSmall capacitors are passive electrical building elementsand found in many electrotechnical devices. Inelectrical and electronic equipments, they serve as energyand charge-coupled memory, frequency dependingresistances, converters or sensors. A capacitor consistsof two electro-conducting surfaces, mostly at small intervals,i.e. the electrodes. Between them, there is alwaysan area with isolating properties, the dielectric,which may be solid or liquid. The case of one of theelectrodes formed by a conducting liquid refers to anelectrolyte capacitor. The dielectric is found in the aluminiumoxide (Al 2O 3) or tantalum oxide (Ta 2O 5) of theelectrolyte capacitor, generated as a chemical reactionbetween electrodes and electrolytes. Most current designsare winding capacitors (i.e. paper sheet, syntheticsheet, metal paper systems), mass capacitors (i.e. ceramicand electrolyte capacitors) and layer capacitors(Hentschel 2000).Due to the electrical insulating property, diffi cult infl ammability,chemical and thermal stability of polychlorinatedbiphenyls (PCB’s), these chemical chlorine compoundswere often used as dielectrics in paper capacitors.As a consequence of their hazardous impacts onhuman health (BAG 2006) and their extraordinary stability,the production and application of PCB’s in Switzerlandwas generally prohibited in 1986. On an internationallevel, the production and application of PCB’s wasbanned, fi rst in open systems in 1978 and then broadlyprohibited in 1986 (UNEP 1999). Various non-conductiveoils, mainly without halogens, were used as substitutesfor PCB’s. But as these substitutes must also havea certain thermal and electrical stability, the environmentalhazard cannot be excluded. In Al capacitors,organic carbonic acids – heavily toxic and corrosive(Baumann 2005) – are frequently used as electrolytes.These electro-conductive matters are often mixed withadditives and solvents.1.2 Legal Provisions and System RegulationsIn 2006, 121 t small capacitors from 96’400 t electricaland electronic waste equipments were removed anddisposed of separately in Switzerland (SENS-SWICO2007) . The Swiss legal provisions differentiate on principlebetween the disposal routes for PCB-containingand PCB-free capacitors. According to the Swiss Ordinanceon the Return, Acceptance and Disposal of Electricaland Electronic Equipments (VREG), Art. 6 Abs. 1lit. a (VREG 1998), “especially contaminated componentssuch as PCB-containing capacitors must be disposedof separately”. The guidance on the VREG (BU-WAL 2000) stipulates high-temperature incineration forPCB-containing capacitors.Specifi c requirements for the disposal of PCB-free capacitorsare not defi ned in the Swiss legislation, unlesstheir classifi cation as “heavily contaminated components”can be justifi ed. According to the VeVA Waste Catalogue(Ordinance on the Handling of Waste), PCB-freecapacitors are assigned to the other wastes which aresubject to control (Waste Code: 16 02 16 [ak]).In Annex 2 (EU 2002) of the European WEEE Directive,the removal from equipments and a separate disposalof PCB-containing capacitors and electrolyte capacitorswith environmentally relevant matters (height> 25 mm; diameter > 25 mm or proportionally similarvolumes) are stipulated. Following the European WasteCatalogue, these capacitors are also ranked as hazardouswaste.The Treatment Requirements of the Swiss system operatorsSENS and SWICO on the disposal of electrical andelectronic equipments are ruling the handling of smallcapacitors in accordance with Swiss and Europeanstandards. Basing on the defi nition in Annex 2 of theWEEE Directive, all the PCB-containing and electrolytecapacitors shall be removed from the equipments anddisposed of separately.In practice, a differentiation between PCB-containingand PCB-free capacitors is diffi c ult – also for qualifi edpersonnel – cost and time intensive, and therefore rarelydone. Available auxiliary documents for identifying6