Why don’t other brands test each tuna for its mercury level?

You would have to ask the other brands. We started as a technology company and invented proprietary testing technology to screen seafood for mercury. We offered to test and certify purity for other brands but every brand we approached declined. So, we used our technology to start our own brand, and we call it Safe Catch. Safe Catch is the only brand that tests every single tuna to a strict mercury limit.