I thought this would be an appropriate subforum to post this in, but if any mods think it belongs elsewhere feel free to move it. I thought it might be helpful for anyone who is not already aware of this fact.

I recently purchased a drain cleaning product when looking for a potassium hydroxide solution. I checked the MSDS on multiple sources and they all said 45% potassium hydroxide 55% water. These were the only two chemicals listed in the composition section of the MSDS. So I purchased the product, intending to use it for an extraction.

A couple of days layer, when I got the basifying step of the extraction, I went to measure out 200mL of this supposed 45% potassium hydroxide solution. When I poured it into the Pyrex measuring cup, it was bright blue... I was a little bit surprised by this as I was under the impression that a 45% KOH solution would be clear. I double-checked the MSDS and no other ingredients were listed. Needless to say, I will not be using this product for any extractions.

So the moral of the story is: industrial-grade products may contain dyes and other ingredients that may not affect the performance of the product when used for the purpose it is sold for. Because these additives would not affect the performance of the product when used for its intended purpose, the manufacturer might not be required to list them on the MSDS.

Be careful what products you use for your extractions, folks.

Good to know. "Inactive" ingredients arent always inactive.

Exactly. They may be "inactive" when it comes to unclogging a sink, but they could very well be absorbed by a NP solvent leaving the alkaloids contaminated and probably pretty hard if not impossible to clean.

Are you aussie?

I know they add blue dye to herbicide so people dont eat poisoned bush tucker, wouldnt surprise me if they added it to poisons and caustics in general. If so you may have to do a bit of research to find an untainted product- solids probably being a better bet.

I`d write to the company and ask wtf was the blue if the MSDS didn`t list it.

But yeah better find a cleaner base in the meanwhile

No, Auxin, I live in the good ol' U.S. of A. This is the first time I have had problems finding a pure (enough) reagent/solvent sold locally, and I live in a relatively small town of ~8000 people.

Thanks, endlessness. I think I will contact the company and find out. I typically use 100% NaOH for my extractions, which I can purchase locally. But I was hoping to try KOH for a cactus extraction, as many people seem to prefer to use KOH for cactus.