Bagel Board Update

I see bagel boards were discussed here several years ago.

Recently, I found some burlap in my garage, washed it, it's now drying, and I want to use it to make bagel boards on cedar boards cut to the size of my oven.

So, I've read all of the posts here and elsewhere about food grade burlap. It's hard to find and in quantities much more than I need. I can't really tell if what I have is food grade or not. Maybe someone knows a way to tell from the numbers or printing on the burlap.

But if it's not food grade, and I want to use it, what's the worst that can happen? It's only on the burlap for three minutes before the rest of the bake on a baking stone. If anyone has any ideas, I would welcome them.

Thanks and Happy Holidays.