The Government Laboratory supports the enforcement of environmental protection legislation and the implementation of various environmental programmes through comprehensive analytical and advisory services. In 2005, the laboratory performed 227 732 tests on environmental samples including air, water, sediment, biota and waste samples, and provided a large volume of useful data for environmental programmes such as background monitoring, special studies and investigation of illegal discharges. The laboratory's commitment to protecting the environment is further exemplified by providing round-the-clock support in the handling of emergencies involving chemical spills or suspected emission of noxious and irritant gas. As part of air quality management, vehicular diesel fuel and unleaded petrol are also routinely tested against legal requirements.

The laboratory has continued to offer technical support to the EPD on a number of special study projects, particularly those on dioxin such as the monitoring of dioxin emissions from the Chemical Waste Treatment Centre during the incineration of dioxin-contaminated residues, the study of air quality at Discovery Bay, Penny's Bay and landfill sites, and the measurement of dioxin levels in fly ash samples collected from crematories. The laboratory has also contributed to the EPD's environmental impact studies and ad hoc projects including the analysis of environmental impact studies and the analysis of environmental samples for organic pollutants under the Toxic Substances Monitoring Programme, which keeps toxic substances in the marine environment under close surveillance. The test parameters include dioxins, polychlorinated biphenyls, organochlorine pesticides and polycyclic aromatic hydrocarbons.