Nine-volt battery batteries were formerly made in this size. They had higher capacity than the then-standard carbon-zinc types, a nominal voltage of 8.4 volts, and very stable voltage. Once used in photographic and measuring instruments or long-life applications, they are no longer manufactured as mercury is highly toxic and accumulates in the ecosystem, posing a risk to humans and wildlife. Most battery voltage testers and chargers that can also test nine-volt need another snap clip to hold the battery, while cylindrical batteries often share a holder that may be adjustable in size. Because of the proximity of the positive and negative terminals
Sarah Liao annual air monitoring project. This program was designed to provide extensive background environmental data, which continued for five years. She then spent over seven years establishing and administering the program on Environmental Health & Safety at the University. Another area of work was the management of toxic and hazardous materials (chemical and biological) used in the University, including the procurement, storage, delivery, use, pre-disposal treatment and final disposal of these substances. At the same time she conducted large scale studies relating to workplace health and safety, hazard identification, risk assessment and environmental problems in a range of Hong Kong industries.