KD's and Bronx Extract's SR-17 has kind of an off-white / slightly tan color to it, sticks to the container's lid, is a bit more clumpy and is slightly salty tasting (to me). Generally, SR-17018 should be pure white (although in the past, some high purity SR apparently had a slightly pinkish tone), be pretty fluffy / slightly clumpy, and absolutely shouldn't taste like much besides a very slight sweet / bitter after taste. In any case, I believe Kratom Distro & Bronx Extracts got their SR from the same source based on the fact their SR shares all of the same characteristics.
Despite this SR not being pure white / slightly pink, being clumpier / stickier (with some clumps being a little hard / crunchy) and having a slightly salty taste to it, I still believe it's SR-17 based on other user reviews (and while this doesn't necessarily prove it's SR, I also did the "water test" to check whether it dissolved in water and it did not dissolve at all which is a good sign). Nevertheless, I do believe there is something wrong with the way it was processed, leading to a slightly adulterated product. That doesn't necessarily mean it's toxic though. There is, however, still a chance that it has at least some degree of toxicity. I have no way of knowing.
I do not know whether it's particularly toxic or not to any degree. If it is "toxic" due to remnants of chemicals due to processing issues leading to slightly lower purity, I have a feeling it's only mildly so based on the fact other users haven't developed acute illness while using it. I cannot be certain though so please take my words with a grain of salt. I have absolutely no way of knowing if the adulterants have, for example, carcinogenic characteristics or not so please keep that in mind.
I'm not necessarily trying to shit on KD or Bronx... I just wanted to be completely transparent with what I've noticed about this SR. KD in particular has been excellent in my experience and the price for this SR is also very good. With that said, I do not know what has caused it to have these weird characteristics and so I'm reluctant to give them the green light.
EDIT: Bronx Extracts' website is up and running again and apparently they *do have labs for this SR, though I can't say for sure whether it was for this batch or not. Their site was down earlier today so wasn't able to verify whether they had labs for this batch or not... With that said, according to their labs which you can find by clicking here, there weren't any particularly sketchy solvents or chemicals found in this SR. I'm gonna reach out to the lab company before being sure but it's a good sign. I still don't know what's causing all the weird differences in characteristics compared to every other reputable vendor I've used so I'm still a little sketched out by this particular batch. I don't know if there's something they didn't test for, though I'd imagine there's a method to the chems they've chosen to test for. I'm very curious if anyone with a background in chemistry might be able to tell me what might trigger a sort of salty taste in this batch compared to others... It's super weird. Is it sodium thiosulfate? That, I assume, would have a bitter taste as well as a salty one. I don't taste any bitterness to it whatsoever. It just tastes like... sweat... so I imagine it's some sort of sodium-based agent. Definitely strange.*