In Hong Kong, PCBs are mainly used in transformers and capacitors installed many years ago. From 1987 to 2001, surveys on PCB equipment have been conducted by the Environmental Protection Department (EPD), the Government of the Hong Kong Special Administrative Region (HKSAR). Results of the surveys revealed that the number of PCB equipment has dropped significantly over the past few years.

In the survey of 1987, there were 167 PCB transformers, 6,677 PCB capacitors and 71 PCB equipment owners. The most recent survey revealed that there is no more PCB transformer in use and the number of PCB capacitors are 296.

There is currently no statutory phasing out plan or control for PCB equipment under use in Hong Kong. The phasing out of PCB equipment was probably due to the owners' awareness of the harmful effect of PCBs fluid and that a large part of the PCB equipment has already reached the service life.

The recent survey also revealed that 3 PCB owners, who owned 44% of the existing PCB equipment, planned to phase out PCB capacitors in one or two years. Therefore the number of PCB equipment would be greatly reduced. With the wider recognition of the potential hazards associated with PCBs, the use of PCB equipment is diminishing.

New transformers or capacitors installed in premises as replacement of old PCB were either of dry type or fluid type with silicone oil as dielectric fluid. No new PCB equipment was identified.

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

PCB capacitors

PCB transformers and PCB owners in Hong Kong

PCB is classified as a chemical waste, under the Waste Disposal (Chemical Waste) (General) Regulation, which is subject to the notification/direction requirements under the Regulation and the Waste Disposal Ordinance. There are legislative controls on the packaging, labelling, storage, collection and disposal of PCB waste. 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 (WDO), 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 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, PCB waste producers are required to store the PCB waste in a designated storage area used for the storage of containers of PCB 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 vapor in the event of spillage or leakage.

Other requirements such as Hazard Warning Panel for the Storage Area could be found in the Code of Practice on the Handling, Transportation and Disposal of Polychlorinated Biphenyl Waste published by the EPD. The document is accessible in the EPD's website www.info.gov.hk/epd/

The recommended method of safe disposal of PCB is by incineration at temperature above 1100 with a mean residence time of 2 seconds and minimum excess oxygen content of 3%.

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.

Notification has to be given to EPD, which will issue appropriate directions for disposal at landfills. All unloading and placing of the waste at the landfills should be carried out in accordance with the instructions of the disposal site staff.

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 creation to the 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; the waste collector will retain a further copy of the form upon delivery of the waste to a final reception point. The staff of the final reception point will retain the original copy. Each party in the waste disposal chain has to keep the copy for at least 12 months.

The quantities of PCB waste disposed of at the Chemical Waste Treatment Centre (CWTC) and the South East New Territories Landfill (SENT) during the period from 1994 to 2001 are as shown below:

PCB Waste Treated

The PCB waste is usually generated when PCB equipment is disposed of. In the past decade, PCB equipment owners have been phasing out their equipment and the remaining inventory is small. The proportion of PCB waste is very small when compared with the total quantity of chemical waste generated in Hong Kong, which is in the order of 100,000 tonnes per annum.

Air

The average annual concentration of total PCBs in the air were as follows:

Year/Places Average concentration of total PCBs in the air, Hong Kong (ng/m3) 1998 0.56 1999 0.87 2000 0.65 2001 0.39 Tokyo** 20 Sweden** <0.8-3.9 Germany** 5-10 United States** 5

** source from Mitchell D. Erickson, Analytical Chemistry of PCBs, 2nd Ed., Lewis Publishers, 1997

The average concentration of total PCBs in the air in Hong Kong are low when compared with other places.

Water

PCBs were not detected in any of the 20 marine water sampling locations, with detection limit of 0.1 mg/l.

Marine Sediments

Sediments samples were collected using grab samplers and analyzed for 30 physical and chemical parameters because many inorganic and organic contaminants in seawater are associated with particulate matter, which eventually settle and become part of the bottom sediments. Sediments are important habitats supporting marine life. The concentration of total PCBs and some heavy metals were analyzed.

Although the use of PCB equipment is diminishing, there is increasing concern of their presence in the environment because of their persistent characteristics and their bioaccumulation in the food chain and toxic effects could affect aquatic organisms and human health.

In the past five years, the concentrations of total PCBs found in the sediments of Hong Kong were considered to be low. All stations in the territory, except the western part of Victoria Harbor, had total PCBs concentrations below 23 mg/kg.

Total polychlorinated biphenyls (PCBs) in marine sediments in Hong Kong. 1997-2001

The highest concentration of total PCBs in sediments was found in Kwun Tong Typhoon Shelter. It was the only location in the territory where the total PCBs exceeded 180 mg/kg dry weights. Five other typhoon shelters around Victoria Harbour: Causeway Bay, Rambler Channel, Yau Ma Tei, To Kwa Wan and Chai Wan were found to contain moderate amounts of total PCBs. The total PCBs in all other typhoon shelters were low.

Total polychlorinated biphenyls (PCBs) in typhoon shelter sediments in Hong Kong. 1997-2001

The above information showed that the concentration of PCBs in the environment of Hong Kong was considered to be low. Notwithstanding, PCBs are very persistent in the environment and their bioaccumulation effects in the food chain should not be overlooked. As the phasing out of the PCB equipment continues, their disposal needs to be closely monitored to prevent any contaminations to the environment. The general public as well as PCB equipment owners and operators need to be educated about the harmful effects of PCBs to the environment and human health. PCB waste should be properly disposed of.