Welcome to the Bunnings Workshop community. Thank you so much for joining us and sharing your question about H3 structural pine being treated with CCA.
When purchasing structural timber CCA-treated pieces have a stapled tag at the end of the timber piece. The same goes for LOSP treated timber, they usually have a digital print on the side or end of the timber piece. Did you have a specific size in mind? I would be more than happy to contact your local store for you and ask what they carry in stock.
If you need further assistance, please let us know.