This is cool. It’s very small amounts.
The key issue is that they are making antimatter at CERN but the magnetic fields at CERN impede studying/analysing it.
Checking in with a nearby physicist, the amount is so small that even in the worse case it would be unlikely to set off a radiation detector.
In return for this sagesse, I was subjected to several witticisms on the detectable rate of decay in the bananas we have awaiting to be turned into banana bread.