On 17 January 2012 Orica reported a mercury leak at its Port Botany plant, the second mercury incident since August 2011. In a series of samples of environmental air, the EPA recorded a mercury level of ; more than double the regulatory limit of . The leak occurred in December 2011 and Orica failed to report the leak to authorities until the following month. The site of the breach was the thermal desorbtion stack at the company's carpark waste remediation project, which was closed when the breach occurred. The NSW Environmental Protection Authority said the incident was not linked to the mercury emissions breach in September at Orica's other Botany site on Beauchamp Road.