CCA is bad for infrastructure cable. It is even worse when CCA is used for patch cables, as alluminium breaks very easily.
20% of patch cables from Rectron had faults from the beginning, they did sync Gigabit initially, but minutes later link was dropping to fast Ethernet. I ended up making my own cables, had to use solid copper wire in emergency, as it was only things I had.
If it doesn't say pure copper, it is CCA.