What is black mould?
If any of your dates have unusual black spores, this is black mould (Aspergillus spp.), which attacks the dates while they are still growing on the trees. Normally these should be sorted out after harvesting, but it is of course possible that the odd date may slip through. EU regulations allow up to 4% infestation (2-3 dates in a 1kg box). However, we aim for 0% and generally do not allow more than 1% infestation.
Mould can only be dangerous for people with weakened immune systems. Therefore, the other (non-infested) dates in the pack can be consumed without hesitation.