  In this talk I present a short review of primordial magnetic helicity effects
on Cosmic Microwave Background (CMB) temperature and polarization anisotropies.
These effects allow us to test for cosmological magnetic helicity, however,
very accurate CMB fluctuation data is required. This scheme for magnetic
helicity detection is valid only for a cosmological magnetic field with a
present amplitude larger than $10^{-9}-10^{-10}$ Gauss.
