PROPERTY managers are playing their part in the battle to protect Hong Kong's environment. Chlorofluorocarbons (CFCs), polychlorinated biphenyl (PCBs) and Halon Gas are all potential pollutants in every day use in buildings throughout the territory. Hong Kong, as a party to Britain's ratification of the 1989 Montreal Protocol, has agreed to phase out the production and use of substances that deplete the ozone layer. Late last year, delegates of 93 countries met in a United Nations-sponsored conference in Denmark and agreed to accelerate this programme. Property managers are now required to assess their building's performance and take corrective action. CFCs are extensively used in air-conditioning equipment in the territory's buildings, including CFC-11 and CFC-12. Scientists have discovered that their release into the atmosphere depletes the world's ozone layer. After January 1, 1996, the use of CFCs will be ''limited to those applications where more environmentally friendly alternative substances or technologies are not available''. Property managers who find air-conditioning equipment using CFCs, can either choose to replace plant, to adapt the equipment to use less damaging refrigerants, or, in the short-term, instal recovering/recycling devices to prevent CFC escape. Legislation in the use of CFCs is tightening and the recent passing of the Ozone Layer Protection (Controlled Refrigerants) regulation makes provision for strict observance of control regulations, with heavy fines for offenders. Halon gas, of which BTM (Bromotrifluoremethane) and BCF (Bromochlorodifluoromethane) are examples, is another type of ozone-depleting substance to be phased out under the Montreal Protocol by next year. They are widely used in fire-fighting installations. The Environmental Protection Board is establishing a database on major Halon gas users, with property managers charged with the task of timely replacement. PCBs are widely used in earlier electrical capacitors and transformers, as lubricants, or for heat transfer. This substance, toxic to man and damaging to the marine ecosystem, has led to an outright ban in many countries. Eric Lee and Gerry Kipling are directors, property management, of Jones Lang Wootton and, in Hong Kong, its use is subject to a strict code of practice.