OOPs, I made a mistake. I said I don't use Sulphuric acid. There is none in the wine test kit. I have to check if I can get h2so4 at our Home Brew store.
If you are a professional brewer and you need to be able to show a particular certification, then I know nothing about this.
But pool chemicals go in water that will be ingested at least by accident.
For an example the 50 pound bag of Bicarb that I am using now is NSF Certified to ANSI/NSF...
Swimming pool Acid is close enough to food grade. People drink pool water all the time, if only by accident. Most pool chemicals are of Water Treatment grade which might even be better than food grade.
I have a pool service company. I buy 50 pound bags of Bicarb and CaCl2 and NACL for pool...