The real reason there is so much controversy is that Ronald Reagan used to do commercials for "20 Mule Team" brand borax products. Ronnie boy was the only American president (that we know of) who had Alzheimer's while sitting in office. Simultaneously, Nancy Reagan was the only first lady, that we know of, to use Astrology to guide decisions. Yeah, any controversy is due to the Reagans and taint by association!
On a more serious note, one of the products being used nowadays to avoid the lengthy list of allergens in modern household products is borax. Dyes, perfumes, ISO chemicals that are in products for God know why ... cause people to have nasty allergic reactions. Borax is simple, safe, generally considered hypoallergenic, and very low toxicity.
As more evidence, there is actually an industrial town in Southern California called "Boron". You can guess what they mine there. Nobody in that town, nor the workers, have any ill effects from the process of mining boron and making borax. Living near refineries, on the other hand, has serious medical consequences!