Mold in the basement: moisture from below or condensation problem

Hydrogen peroxide should (also) work against mold. It smells significantly less strong.

Acute yes,
but it is not sustainable.

I use benzoic acid as a saturated solution in isopropanol (70%).
Simply spray the walls with it; that prevents new mold for several months.

Benzoic acid was even used in food before, so it is comparatively harmless.
Only as an aerosol you should not inhale it, as it causes coughing fits.
So definitely use respiratory protection and let the solution take effect!