Hazards of Improper Disposal of Chemical Waste includes

(i) toxic effects to workers;
(ii) adverse effects on air, water and land from spills;
(iii) fire hazards; and
(iv)biological disruption to sewage treatment works where waste enters the sewage system.

According to the information from the Hong Kong Environmental Protection Department (EPD), use of products containing PCBs are not available in the market, PCBs waste originate only from products purchased in the past and are still in use.

Small PCB capacitors have also been used in the starter units of fluorescent lights and fractional horsepower motors of the type used in domestic and light-industrial electrical equipment. Typically they contain about 50g of the lower chlorinated PCBs, mostly absorbed in the windings. Wastes which may contain PCBs should be treated as hazardous unless and until laboratory tests prove their absence.

For equipment and products with proper nameplates, the presence of PCBs could be easily verified by checking whether any of the trade names shown in the list appears on the nameplates. If identification by trade names is not possible, the supplier or manufacturer should be contacted for details, or arrangement could be made with a qualified laboratory to undertake analysis.

Most electrical capacitors manufactured since the 1930s were, however, filled with PCB liquids. It should be assumed therefore that all power capacitors regardless of size or use contain PCBs except where alternative (non-PCB) liquids are clearly indicated on the nameplate.

Once it has been confirmed that equipment contains PCBs, planning for removal of the toxic material needs to begin. As with analyses and monitoring, to ensure that such work is carried out under appropriate conditions by trained staff.

Draining the equipment will remove most of the PCBs, but much is retained in the interstices, in porous materials of construction, and on internal surfaces of the equipment, so repeated draining and flushing with mineral oil possibly separated by brief periods of service, will eventually lower PCB content to acceptable levels- often taken as 2mg/kg - at the expense of generating large volumes of contaminated oil during sequence.

In Hong Kong, PCB waste is classified as a chemical waste under the Waste Disposal Ordinance, the packaging, labelling, storage, collection and disposal of PCB waste is controlled by the aforesaid legislation. These regulations cover (i) handling by trained operators, (ii) transport only by licensed carriers, (iii) storage in secure premises away from sensitive areas.

According to the Waste Disposal Ordinance, any PCB waste producer who produces or causes to be produced PCB waste including old PCB equipment must therefore register with EPD as a chemical waste producer, they should also register with EPD when they intend to dispose of any PCB waste including old PCB equipment for suitable disposal arrangements to be made.

Before registration with EPD is completed and the disposal method be directed, PCBs waste producers are required to store the PCBs waste in a designated storage area used for the storage of containers of PCBs waste, such area should comply with the following requirements:

a.	not be used for any purpose other than the storage of chemical waste;
b.	be enclosed on at least 3 sides by a wall, and
c.	have adequate ventilation to prevent the formation of any dangerous or harmful concentration of vapour in the event of spillage or leakage.


PCB containers:Double bung metal drums




Labelling for PCB Waste

The recommended method of safe disposal of PCBs is by incineration at temperature above 1100 with a mean residence time of 2 seconds and a minimum excess oxygen content of 3 %. Arrangements could either be made with the Chemical Waste Treatment Facility or experienced overseas waste disposal contractors for the disposal of PCB waste. Prior approval from EPD should be sought for the export of PCB waste to overseas facilities for disposal.

In normal circumstances, decontaminated PCB articles and small PCB capacitors (incorporated as a component of domestic appliances) could be accepted at landfill sites. These articles include the properly decontaminated containers and mechanical equipment such as pumps, heat exchangers, etc. unless the landfill operator advises that there is undue concentration at the lanfill site, then will be treated as the same way as large capacitors.

A cradle-to-grave control has been introduced under the Regulation, as a mechanism of keeping track of the movement of chemical waste from its point of arising to its final disposal site.

For every waste consignment, a waste producer needs to complete the trip-ticket before the waste will be accepted for collection from his premises. The waste producer has to keep one copy as a record of consignment, and the waste collector will retain a further copy of the form upon delivery of the waste to a reception point manager. The reception point manager will retain the original copy.

The Trip-Ticket System

The most common replacement for PCBs is mineral oil (paraffin), but this represents a return to the practice of the pre-PCB era. Flammability was a major reason for the replacement of mineral oil dielectric fluids by PCB and many equipment-holders will be concerned about increased fire risk attending the replacement of chlorinated materials by mineral oil. The response at some facilities has been to blanket the dielectric fluid with inert gases to reduce the risks of fire when electrical equipment overheats. The use of alternative organo-chlorine materials and of some new formulations has also been suggested.

According to EPD, non-PCB materials are gaining wider use in capacitors for fluorescent light fittings, and the use of capacitor start motors in domestic appliances is diminishing due to design changes.

The regulations I mentioned such as the Waste Disposal (Chemical Waste) (General) Regulation and A Code of Practice on the Handling, Transportation and Disposal of PCB Waste are accessible at the government web sites.  So if you want to know details, please check the website.

With the wider recognition of the potential hazards associated with PCBs, the use of PCB equipment in diminishing. However, PCB wastes will continue to be produced for many years from the gradual replacement of existing PCB equipment and retrofilled equipment. Thus for every country, safe disposal of PCB waste and establishment of guidelines to waste producers on PCB waste disposal are important to ensure PCB waste be disposed in an appropriate manner, in order to minimize the impact on the environment.