I believe almost everyone doing MHRB extractions are using technical grade solvents - the kind you get at hardware stores.
Is this simply because food-grade naptha is for the most part impossible to get? Or is their a reason that tech grade naptha is safer/less gross than tech grade limonene?

I can't imagine anything highly toxic like lye even has a food grade. Seems crazy.

yes, food grade lye is still highly caustic, of course.. But it is used for example to raise the pH for olive conserving (and of course it will be diluted, not so high pH like for extractions of MHRB )

Easy; you get food grade sodium chloride (aka salt) and electrolyse it to get sodium hydroxide. You take care everything is "food grade" clean and that the chlorine gas by product is carefully dealt with (not difficult in a proper facility).

And by the way, "Food grade" is not a measure of toxicity. Tap water is food grade but it can drown you. It's all about the dosage and how you use it.

There is no lye that is safe to ingest.

peace
DB

misinformation

Food Grade is just a measure of purity and the process to get it there. It has NOTHING to do with how toxic/edible the actual pure product is.

It is hard to find this information, but I asked green-terpene about it and it, they replied:

"About our food grade d-limonene, it is labeled as such to indicate the level of purity. This is an industry standard, we do not add anything to our d-limonene it's straight from the orange peel. This allows clients to do with it as they wish. Because we are marketing an all purpose cleaner we are not at liberty to advocate internal use or to give any advice."

Though tests of people consuming 20g of limonene a day for a week produced diarrhea and indigestion of proteins... or something like that. The LC50 (vapor toxicity) was incredibly low as well, scary low.
In my opinion is that Limonene is only slightly less toxic than xylene, but this opinion based on over-reaching the basic facts

Another site on taxidermy mentioned this:

"Food grade and Technical grade hydrogen peroxide are essentially the same. However, the FDA regulates among other things the processing of Food grade hydrogen peroxide.

For Example:
The manufacturer produces 10 drums of technical grade H2O2. He would test the first and the last drum for quality and purity. The FDA inspects or test all 10 drums. All 10 drums are now considered to be food grade H2O2 after the additives added by the manufacturer for compliance. If the packager pours food grade H2O2 out of one of those drums into a smaller container, it is no longer a "food grade" unless that smaller container is also tested for the FDA compliance."



This mention of food-grade lye confirms my suspicions because eating food-grade lye would kill you just as fast as tech grade I'm sure. It is pure sodium hydroxide.

Don't eat lye.

AAA-Chemicals d-limonene is TECHNICAL grade.
I just got an email from them.

Guys, food grade refers to purity standards. Ingesting enough food grade lye will kill you just like ingesting enough food grade water will kill you.

yeah.. as I said, lye is used here in olives conserving... The dosage makes the difference

(in other words, dont try to ingest a MHRB lye soup )

Misinformation again.

Lye is used in the cooking of some stuff, like pretzels. This recipe uses a strong solution of lye that gives a pH of 14 to dip the pretzels. There's plenty of lye leftover on the pretzels after the dipping.

"don't eat lye" is not a useful comment. The poison is always in the dosage. Of course I wouldn't eat a teaspoon of lye, but a 40mg of lye dissolved in ~300ml of water i'd gulp without fearing ill effects.

Let’s clarify a few things here. People are not getting the meanings clearly.

Anything that is food grade has to pass FDA inspection. It can only be stored in FDA approved food grade or USP grade containers. At no time can it be exposed to non-food grade substances in sufficient quantities. Each batch needs to be tested for known carcinogens, and other toxins. If any such things are found in the solvent that are not approved for use in food grade applications, the batch can not be labeled as food grade, but can be labeled as technical grade instead. That is why technical grade is cheaper. Technical grade doesn't need to pass rigorous FDA inspection.

Food grade means that the solvent can be safely used for processing food, or safely used as an ingredient in food in some cases. Each solvent has a different set of rules defined for it when it comes to contact with food. Some solvents can be used in the processing of food, but cannot be present in the final products. Others can be. It all depends on the limits defined by the FDA.

D-limonene can be present in supplements in doses up to 1000 mg while xylene cannot. Even if the xylene was food grade xylene, it cannot be present in food or supplements.

Defining something as food grade means that it’s pure to a certain degree and that it will not leave toxic residue behind in the food after the solvent is removed from the food.

Highly toxic substances can still be food grade. But they must be pure enough that their use in food processing will not contaminate the food, and the final product must have food safe acceptable levels of the toxin. Certain things like DMSO are banned by the FDA for use in food. But you can still get food grade DMSO. But they cannot state that it is food grade because the FDA doesn’t allow it in food at all.

Technical grade can be contaminated with a whole bunch of crap. Pretty much anything can be in it. The impurities do not have to meet FDA standards for use in food processing. It can leave behind all sorts of highly toxic residues after evaporation. It can be stored in non-FDA approved containers and make you seriously sick if you ingest it. It can cause cancer or others health problems or contain impurities that do and still be sold as technical grade.

You should not use technical grade solvents ever. But if you do, you should distill them first, and you should make sure there is as little left in your final product as possible.

With food grade d-limonene, the FDA allows up to 1000 mg of it in food, if I recall correctly. That amount is believed to be safe for human consumption. But technical grade d-limonene is banned from contact with food, for obvious health reasons.

While I think the FDA is highly corrupt, they still serve a purpose when it comes to preventing toxins from getting into our water and food supply. If they accept something as food grade, it doesn’t always mean it’s safe. NutraSweet is food grade, and very bad for you to ingest in any quantity. This is the problem with the FDA. If you have enough money, you could get almost any toxin approved for use in food (of course this is an exaggeration, but still true to a certain degree).

Ron, you feel this way about all tech-grade solvents? I don't perform extractions, but it does surprise me to see this sentiment on a board where lots of people use naptha, acetone, lye, and other stuff right from the hardware store.

What kinds of contaminants could be harmful? I seem to remember you mentioning some tech grade HCL or solvent that was 99.x percent pure and saying that any impurities at that level would be mostly harmless.

Whatever you read, you got my intended meaning wrong. I only recommend that people use food grade or USP grade chemicals in their extractions, is the extraction in meant for human use.

HCl sold for use in pools is not the same as technical grade HCl. HCl sold for use in pools comes in contact with human beings and so it is more highly regulated than technical grade and cannot be contaminated with anything that is greatly harmful to humans or its use in pools would be prohibited. So it’s safer than technical grade HCl. But even then, the contaminants present are not meant for ingestion. It should really not be used for any extraction where the end product is meant for ingestion. But it’s safer than technical grade.

It’s all about risk level. Food and USP grade have the least health risk for a given solvent, and so those should be used.

If a tech doesn’t use food grade solvents and chemicals, it should not be used unless you understand the risks and are willing to risk your own health.

As for what kinds of toxins can be present in technical grade, and what exactly could make you sick, well it could legally contain viruses, bacteria, feces, carcinogens, etc. Food grade cannot contain acceptable levels of any of those things.

Wow who knew a simple post would make such a stir. Lol

A friend of mine used the blender style limtek and was quite successful for a few rounds starting with 150 than 300 grams of powdered MHRB. He's kind of a lazy guy and since the fumerate keeps better than pure free base crystals he wants a one and done set up to last. a friend of his left town and left him with 12k of MHRB. He happens to work construction and has a mixer for high viscosity sealants and such that mounts on 5 gallon pail. The mixer is stainless shaft and multiple impeller/agitator placement at different depths alon the shaft. He intends to perform the initial acid prep, lime mix and hydration in a solid bottom pail using the agitator as a blender of sorts, letting it run for some time. He intends to use some excess water to ensure viscosity is not so high as to break the agitator (multspeed, 2 hp motor, direct drive) than let it sit briefly to become more doughy. He then plans to transfer the dough into another 5 gallon pail with small holes drilled across the entire area of the pails bottom. This pale will be above and inside the mouth of an upside down nalgene carboy stuffed with cotton and filter paper in the small mouthed neck end (THP). Below this is a pyrex car boy (with bottom spigot) with a wide funnel on top to catch the drippings from THP. Fumeric acid mixture to be done in large glass carboy, aloud to settle, water/DMT fumeerate decanted from bottom initialy via spigot, finished via pipette. D-limonene recycled. His biggest concern is mixing d-limonene into the second 5 gallon pail. He wants to perforate the bottom of the pail as an intermediate instead of using cotton filter directly. He is afraid that the mixer will ripp the filter apart. He is however concerned that improper perforation of a 5 gallon pail might not create adequate flow resistance to maintain a proper dwell time for the d-limonene especially since he wants to keep the viscosity of the d-lim/dough bucket somewhat low as not to break the electric mixer. Any body have any comments on this proposal. I would love to help my buddy out, I know he'd do the same for me...

Thanks for the clarification, Ron.

At least harmful microorganisms would be killed by most of these products, but do you have any advice for people who are going to use tech grade solvents for whatever reason? I suppose it would be hard to prescribe a technique to clean out unknown contaminants in such small quantities.

I believe you would just need to set up a distillation apparatus and distill it...
I might have to do this someday if I keep using limonene.

Not quite; you have no reason to believe that distilling your limonene will remove any of the contaminants, right?

Which are the contaminants you're after to remove? Do they co-distil with limonene? Limonene has a high boiling point often other stuff co-distils with it.

Distillation of limo will definitely leave non-volatiles and high boiling point contaminants behind but not everything. Distillation is not a silver bullet to clean solvents!

Is Acetone you buy from the hardware store Food Grade? How about MEK or Heptane or Naptha? If they aren't food grade, and are technical grade, and you already use these items, then why not order technical grade limonene instead? Even if it is technical grade, it can often be used in place of some of these solvents, but is much more pleasant to work with, and often more safe.