The methyl compounds in anti freeze have the same effect as the Methyl alchohol thats is added to "meths" to theoretically render it undrinkable! So always avoid it as far as possible, of course a splash isn't going to do you any harm, your liver can deal with it, but why take the chance! I would far rather use my tolerance up on the vastly larger quantity of malt whisky you could drink for the same amount of damage!