Nickel is an essential trace metal used in the occupational setting,resulting in both occupational and nonoccupational exposures to individuals at varying levels.Exposure to nickel has been associated with several toxicities and the International Agency for Research on Cancer has concluded that there is sufficient evidence in humans associating exposure to nickel compounds Nickel is an essential trace metal used in the occupational setting, resulting in both occupational and nonoccupational exposures to individuals at varying levels. Post to nickel has been associated with several toxicities and the International Agency for Research on Cancer has concluded that there is sufficient evidence in humans associating exposure to nickel compounds