In addition to toxicity of denatured alcohol and its higher volatility,
from a biological disinfection argument, ethanol has to be more
concentrated to be effective against bacteria. Optimal percentage
against bacteria is 70%.

Isopropanol is a little more toxic toward bacteria, and it is also a
better general cleaner because it has a larger nonpolar part, thus it
has a lower surface tension. Optimal against bacteria is only ~50%.
It's also supposedly cheaper for non-laboratory use because of taxation
of ethanol.