Actually, the Pool Time products (made by Chemtura) are basically the same as the Bioguard and Aqua Chem products (and very similar to the Proteam trichlor products, which are made for Haviland by Chemtura).

These trichlor tablets contain borax as a buffer, which is not necessarily a bad thing. As far as I know Pool Time is only including copper sulfate in the Duo Tabs in addition to the borax buffer. All HTH dual action trichlor (Arch Chemical) tabs do contain copper.

Chemtura has made the MSDS for all their various lines difficult to get. You have to email them since many of their pool products are not in their online database.