Boveda will never humidify beyond the RH on the pack, so there’s no such thing as “too much”. You want to think in terms of using at least the minimum because the more you use, the more efficient Boveda works and the longer they last

Boveda provides the cleanest and most purified humidity of all other products available on the market today.

Note: Do not mix Boveda RH levels within the same container, and do not use Boveda in the same container with other humidification products. They will fight against each other and reduce the efficiency of the Boveda.