I have been making mash in a plastic garbage container for years now
with no ill effects.
When it comes to distilled product I use glass period and again with
no ill effects. These containers range frome 500 ml to 4 liter and are
generally containers scrounged or recycled. Mason jars are generally
readily available and are relatively cheap. My question, rhetorical, is
why gamble with plastic you are unsure of when glass is suitable,
cheap, and readily available.
Just my two cents worth, and not wanting to make an issue of this.