Off flavors possible from plastic mash spoon?

I'm still trying to nail down that stubborn off flavor in my last bunch of brews.I've been using the same plastic spoon for 8 yrs.It is badly scratched and well worn.I typically give it a quick rinse prior to use but never sanitize it as I assumed any nastys would be killed off in the boil.I stir my mash 4-5 times during a 60 min mash,with this spoon,then I use it to stir my wort during boil.Any chance this spoon could impart off flavors?

May as well. You don't need to stir during the boil anyway. If you prefer, use a hardwood paddle or stainless steel spoon.

Very unlikely based on this info but if you are worried switch to something else and see if it goes away.

the amount of chemicals that possibly leech out of the plastic spoon in one brew would be way too small to taste. after 8 years of use, most of what could be leeched out, probably already has been.

if you could measure it, you would get the most chemicals to leech from a brand new spoon, due to mold release agents they use in manufacturing that sometimes leave a residue on the surface, and the fact that leech-able chemicals havnt had 8 years to come out yet. even still, i would doubt anyones ability to taste such small amounts.