  An upper bound on the total cross-section of s-wave electroweak
instanton/sphaleron induced baryon plus lepton number violating processes is
presented. It is obtained by exploiting a recently reported lower bound on the
corresponding tunneling suppression exponent and by estimating the
pre-exponential factor. We find that the present knowledge about electroweak
baryon plus lepton number violating processes still allows their eventual
observability at the Very Large Hadron Collider, even as pure s-wave
scattering. A possibly observable rate at cosmic ray facilities and neutrino
telescopes is presently not excluded, but requires a substantial contribution
from higher partial waves.
