Potassium Iodide (KI) is approximately 76.5% iodine.
I have taken Kelp tablets for about 25 years. If it were toxic... my doctor would have found it by now. I have bloodwork done regularly. Like every 6 months at least. Kelp tablets are 150% ... and yes, they are iodine, too, from North Atlantic Kelp!
Um, yes. Table salt is probably 50% sodium, too. Do you know what happens when you take elemental sodium?
An iodine salt is not the same as elemental iodine. You can take a much higher dose of iodine in the form of potassium iodine than you can in the form of elemental iodine.
Go to ki4u.com, check the tables for the amount of iodine you need to ingest on a daily basis to keep your thyroid saturated, then check how many kelp tablets you'd need to take to provide that amount. I'm not making this stuff up.