'Perfect Pool 3" Giant Chlorinating Tablets' is an algaecide, bacteriocide, and disinfectant. Its Federal EPA registration number is: 3432-61. It was originally approved by EPA on 21 Jun 1985. It has a 'Danger' signal word. It has the following active ingredients: Trichloro-s-triazinetrione. It's approved for 1 sites including swimming pool water. It is also approved for 2 pests and pest groups including but not limited to algae and animal pathogenic bacteria.