Chlorine is considered toxic, corrosive, and an oxidizer: http://www.praxair.ca/-/media/documents-en/safety-data-sheets-en/chlorine-msds-e4580.pdf
This material should be disposed of with our household hazardous waste program for small residential quantities. For commercial quantities, surcharges may apply, see here for details: https://foothillslrrc.com/service/hazardous-waste-paint/