Used Firebrick

[Gulf]

Re: Used Firebrick

I guess my post was confusing Gulf.....I meant how do you test them to see if they haven't been contaminated by any Hazmat or anything like that....

The short answer to that would be buy new. The amount of testing for the numerous amounts of hazardous materials, carcinogens, and other toxic to human materials would be out of the price range of most municipal and state labs to conduct. I understood you to say they were form a fireplace. I interpret that as a residential fireplace. A side from the hardwoods and some softwood used as starter their will be the occasional Christmas wrapping and some plastic toys thrown in. If the brick are from a residential fireplace and all of my above post's criteria were met, I wouldn't sweat it.
EDIT: I just went back and reread the post (not fireplace as I first undrstood, but chimney) Did you mean an industrial chimney?