You must understand that this salt is naturally occurring and very healing since the minerals are bio available; theres more to it than the actual minerals included in the salt but has to do with the energetic arrangement of the crystal structure; I wouldnt be too concerned with residual amounts of platinum and even heavy metals (unless it has been exposed to unnatural sources).
the typical table salt (sodium chloride) is a chemical (man made) and your body recognizes this as a toxin; you need the fine balanced minerals in sea and himalayan salts to fully absorb sodium chloride.
Although pricey, himalayan salt is very beneficial (and delicious)
Mike