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
Toxic Substances Control Act of 1976 safety studies. In this extent of TSCA, the EPA’ s ability is restricted to share information including the company’s identities, the chemical’s structures to any public groups except the designated contractors, or to law enforcement officials. It is important that the state and local environmental non-governmental agencies, environmental advocates and other public groups in obtaining chemical information in order to develop contingency plans and effective emergency responses in cases of highly toxic exposures. However, the EPA can only disclose confidential business information when it determines such disclosure is necessary to protect human health or the environment from an unreasonable risk.