Saturday, December 29, 2007

Probing the mystery of "lab grade Lugol's solution"

Rev B (see Notes)

The ingredients that go into Lugol's solution are purified water, iodine crystals, and potassium iodide. There are two widely-available grades of iodine: "crude" and "resublimed," the latter of which is crude iodine that has been further refined via a vaporization/crystalization process. ACS-grade iodine is resublimed iodine which satisfies the ACS requirements. The following quotations are included to support these statements:

Commercial-grade crude iodine normally has a minimum purity of 99.5% I2: the main impurities are water, sulfuric acid, iron, and insoluble materials (Lyday 1999 [see excerpt below]). Specifications of the U.S. Pharmacopoeia [USP] XVII call for crude iodine to be not less than 99.8% I2. Resublimed iodine is usually 99.9% pure, and American Chemical Society (ACS) specifications call for not more than 0.005% total bromine and 0.020% nonvolatile materials (Anon. 1971).

from Industrial Minerals & Rocks, 7th edition, By Jessica Elzea Kogel p 549

Commercial crude iodine normally has a minimum purity of 99.5%. Impurities are chiefly water, sulfuric acid, iron, and insoluble materials. The USP XVII specifies iodine content of not less than 99.8%. The Committee on Analytical Reagents of the American Chemical Society allows a maximum of 0.005% total bromine and chlorine and 0.010% nonvolatile matter.

from Iodine By Phyllis A. Lyday

So, there's really only one grade of non-crude, refined ("resublimed") iodine which is widely available, and that is ACS-grade. After a batch is refined, it is tested for compliance to the ACS specification , which limits total impurities to 0.01%, or 100 ppm, implying a purity requirement of 99.99%. Considering that the quantity used for dietary purposes is on the order of 5 mg per day typically, total impurities would be on the order of 500 nanograms, or 0.5 micrograms. You probably get more in the air you breathe on a daily basis.

Potassium Iodide

Besides water and iodine, Lugol's solution contains potassium iodide, and the ACS grade is typically used. The spec for Potassium Iodide, ACS
includes a list of impurities and the maximum permissible level for each. Those that aren't listed specifically would fall into the category of "insoluble matter," which is limited to 0.005%, i.e. 50 parts per million. Soluble matter would have been removed by the manufacturing process, so the spec covers everything that could be present, including residues of chemicals used in the manufacturing process. My main concerns would be the heavy metals, which are low to begin with (again, in the single-digit nanogram range), and which Lugol's solution helps the body to expel.

Putting "USP grade" into context

USP-grade ingredients, which are typically ACS (or lower) grade ingredients which have passed certain tests related to their suitability to be used in or on the human body, are also available. In order to legally sell Lugol's solution for human consumption, the ingredients must pass these USP-mandated tests, and certain USP-approved manufacturing standards must be met. I gather that the designation "lab grade Lugol's solution" is Lugol's solution that was made with ACS-grade materials and wasn't subjected to the USP tests. However, I would check the manufacturer's specification to be certain that ACS-grade materials were used.

It is my understanding that J Crow's (, one of the major suppliers of USP-grade Lugol's solution to consumers, uses ACS grade ingredients. They indicate that their product is "USP grade or higher," which is true of anything that exceeds the relevant USP requirements. Considering the high purity of ASC-grade materials, it would seem that the USP testing is a formality which must be performed in order to be absolutely certain that a product is safe for human consumption. However, CHANCES ARE that "lab grade" Lugol's solution made from ACS-grade materials by a reputable company (such as those who manufacture aquarium chemicals) would be essentially identical to the typical USP-grade Lugol's solution.

Considering A) the purity of the widely-used ACS-grade ingredients; B) the simplicity of manufacturing Lugol's solution; C) the fact that manufacturers and resellers probably make reasonable efforts to ensure that they don't contaminate their product (because the purer it is, the better it will work for lab procedures); D) the fact that Lugol's solution is a germicidal; and E) that it helps the body to rid itself of various toxic substances such as heavy metals, I would be willing to use the lab-grade version if it is made of ACS-grade ingredients and manufactured and rebottled by reputable companies. As of this writing, I had been using Clarkson Labs' non-USP Lugol's solution for about two years, and I hadn't noticed any ill effects. Most "lab grade Lugol's solution" is probably quite similar. (Unfortunately, Clarkson's no longer sells to individuals due to the new DEA regulations, which require anyone who purchases more than one ounce at a time to be registered with the DEA. This status is not available to individuals, and even if it were, it would be absurd to register just to save a few bucks on Lugol's solution.)

A readily available form of Lugol's solution is "lab grade" product for aquariums. Kent Marine's product appears to be the most prevalent of these, and according to their Material Safety Data Sheet, it, unlike some lab-grade "Lugol's solution," contains the proper 5% iodine/10% potassium iodide mixture required to be considered genuine full-strength Lugol's solution. (However, I haven't investigated all of the available brands of "lab grade" LS for aquariums - it's possible that they all have this desirable balance of ingredients.) Considering their emphasis on maintaining water purity, I assume that their Lugol's solution consists of ACS-grade materials. (As far as I know, the only ingredients readily available for use in chemical mixtures are ACS-grade. I suppose they could use crude iodine, or go out of their way to find resublimed iodine that doesn't quite meet the ACS spec, but it's highly doubtful.) However, I don't know what grade they use, and I doubt that Kent Marine will supply the documentation required to prove it one way or the other. But because they have a competitor (Warner Marine Research) who touts their product as USP-grade, I'd be willing to bet that they do use ACS-grade materials. If KM's Lugol's solution were made of inferior ingredients, this competitor could steal the market by performing an analysis of the KM product and publicizing it, which I doubt Kent Marine would want to risk. They would also be risking their reputation and the rest of their business. The fact that the competitor hasn't done this might mean that both products are made of ACS-grade materials, so the only advantage the competitor has is the aura of greater purity by means of USP certification. The bottom line is that I would be willing to risk using KM's product, but you will have to evaluate the information and decide whether to take the risk before using it as a dietary supplement.

On their website as of 12/29/07, Warner Marine (WM) made the following claim about their Lugol's solution: "ReefPure Lugol's Solution is the original Iodine tool for the aquarists' toolbox. It is produced entirely from Pharmaceutical Grade (U.S.P.) Potassium Iodide and Iodine Crystals, the highest quality raw material in the hobby. Inferior competing products are produced using poor quality raw materials containing up to 10x the heavy metals and impurities compared to Warner Marine products." However, in light of the information I have provided above, this sounds like sales hype. If they had any data, they would probably present it. But it is a way to get reasonably-priced Lugol's solution, USP, and if it's available locally, it would be the logical choice.

You might be able to find suitable Lugol's solution at laboratory supply outlets that are willing to sell to private individuals and to provide details on their product. I found a couple of such places through Yahoo Shopping, but upon examination of the relevant Material Safety Data Sheets, I realized that their products do not contain the proper proportion of ingredients, or are so loosely specified that the specs are useless.

Conclusion and disclaimer

So, as far as I can tell, "lab grade Lugol's solution," (assuming it's made with ACS ingredients by a reputable manufacturer, and rebottled by a reputable reseller) is fine to consume, just as Lewis Ford claims in his article Iodide/Iodine (also posted below). But I'm not an expert, and I might have missed something, so I cannot guarantee that it is. It's up to you to determine whether I've covered all the bases, to weigh the evidence, (including the fact that the manufacturing facilities and process, and the rebottling facilities, are not USP-certified), and decide whether you want to take the risk of consuming it. If you get sick from it, you will have only yourself to blame. If you die from it, you won't even be able to blame yourself. But if Warner Marine's Lugol's solution, USP is available locally and competitively priced, it's the logical choice, although if you were to analyze the various brands used for aquaria, I suspect they'd all yield similar results.


Rev B:

Was: Considering the high purity of ASC-grade materials, it would seem that the USP testing is a formality which must be performed in order to guarantee that a product is safe for human consumption. With modern test gear, these tests are probably easy to perform.
Is: Considering the high purity of ASC-grade materials, it would seem that the USP testing is a formality which must be performed in order to be absolutely certain that a product is safe for human consumption. However, CHANCES ARE that "lab grade" Lugol's solution made from ACS-grade materials by a reputable company (such as those who manufacture aquarium chemicals) would be essentially identical to the typical USP-grade Lugol's solution.

Was: As of this writing, I had been using Clarkson Labs' non-USP Lugol's solution for about a year, and I hadn't noticed any ill effects.
Is: As of this writing, I had been using Clarkson Labs' non-USP Lugol's solution for about two years, and I hadn't noticed any ill effects.

Tuesday, December 25, 2007

Can I get some fries and ketchup with this crow?

Rev A (see Notes)

It seems that I overlooked a little detail required to purchase more than one ounce of full-strength Lugol's solution at a time: registration with the DEA. I confused it with record-keeping, and none of the companies I contacted about buying bulk quantities mentioned it, or at least emphatically enough to penetrate my skull. Registration is a complex, expensive undertaking reserved for certain companies that handle chemicals, so spend the extra few dollars to purchase one ounce at a time, and get over it.

There is one way to save a few bucks on an ounce of Lugol's solution, and that is to use "lab grade," which, I gather, is made of ACS-grade ingredients but not subjected to USP tests. (I searched extensively, and wasn't able to find anyone who sells anything explicitly identified as "lab grade" Lugol's.) Considering the purity of the ACS-grade ingredients, however, lab-grade Lugol's solution would almost certainly pass the USP tests every time, assuming that such ingredients are used. According the article Iodide/Iodine
by Lewis Ford, lab-grade Lugol's solution is safe to consume.


Rev A: Improved writing in spots (I hope), and eliminated a quoted passage which defines Lugol's Solution, USP. When I incorporated that passage, I was under the impression that "Lugol's solution" ("lab grade") and "Lugol's Solution, USP" were one and the same, and that anything sold as "Lugol's solution" is required by law to meet pharmaceutical standards. However, I was essentially correct, since anything sold as "Lugol's solution" by a reputable manufacturer typically meets the pharmaceutical standards, due to the purity of the ingredients typically used in the manufacturing process, the simplicity of the process, and the germicidal nature of the compound.

Saturday, December 22, 2007

Excerpts from the August 2007 revisions to the DEA iodine regulation

[Does not include sections on registering with the DEA, which is required for purchasing more than 1 oz of full-strength Lugol's solution at a time, and is a major undertaking.]

Federal Register Notices > Rules - 2007 > Changes in the Regulation of Iodine Crystals and Chemical Mixtures Containing Over 2.2 Percent Iodine
Rules - 2007
FR Doc E7-12736 [Federal Register: July 2, 2007 (Volume 72, Number 126)] [Rules and Regulations] [Page 35920-35931] From the Federal Register Online via GPO Access [] [DOCID:fr02jy07-6]
Drug Enforcement Administration
21 CFR Parts 1309 and 1310
[Docket No. DEA-257F] RIN 1117-AA93
Changes in the Regulation of Iodine Crystals and Chemical Mixtures Containing Over 2.2 Percent Iodine
AGENCY: Drug Enforcement Administration (DEA), Justice.
ACTION: Final rule.
SUMMARY: This rulemaking changes the regulation of the listed chemical iodine under the chemical regulatory provisions of the Controlled Substances Act (CSA). The Drug Enforcement Administration (DEA) believes that this action is necessary to remove deficiencies in the existing regulatory controls, which have been exploited by drug traffickers who divert iodine (in the form of iodine crystals and iodine tincture) for the illicit production of methamphetamine in clandestine drug laboratories. This rulemaking moves iodine from List II to List I; reduces the iodine threshold from 0.4 kilograms to zero kilograms; adds import and export regulatory controls; and controls
[[Page 35921]]
chemical mixtures containing greater than 2.2 percent iodine.
This rulemaking establishes regulatory controls that will apply to iodine crystals and iodine chemical mixtures that contain greater than 2.2 percent iodine. This regulation therefore controls iodine crystals and strong iodine tinctures/solutions (e.g., 7 percent iodine) that do not have common household uses and instead have limited application in livestock, horses, and for disinfection of equipment. HOUSEHOLD PRODUCTS SUCH AS 2 PERCENT IODINE TINCTURE/SOLUTION AND HOUSEHOLD DISINFECTANTS CONTAINING IODINE COMPLEXES WILL NOT BE ADVERSELY IMPACTED BY THIS REGULATION. ADDITIONALLY, THE FINAL RULE EXEMPTS TRANSACTIONS OF UP TO ONE-FLUID-OUNCE (30 ML) OF LUGOL'S SOLUTION.
Persons handling regulated iodine materials are required to register with DEA, are subject to the import/export notification requirements of the CSA, and are required to maintain records of all regulated transactions involving iodine regardless of size.
DATES: This rulemaking becomes effective on August 1, 2007. Persons seeking registration must apply on or before August 31, 2007 in order to continue their business pending final action by DEA on their application.[...]Comments Regarding Iodine Products Used for Nutritional Supplementation
Twelve comments expressed concerns that the proposed regulations would adversely impact the availability of products for use as a dietary source of iodine. These comments detailed the use of iodine products as part of a nutritional program to supplement iodine levels for various health purposes (e.g., the normalization of thyroid function, prevention of breast cancer recurrence, or supplementation during pregnancy as a program to prevent autism in offsprings.)
Eleven of these comments expressed concern that the regulation would adversely impact the availability of a specific formulation known as Lugol's Solution. Lugol's Solution is a 5 percent aqueous solution of iodine in combination with 10 percent potassium iodide.
Most of these comments detailed the importance of Lugol's Solution as a source of milligram doses of iodine as part of a daily health program of disease prevention. Commenters noted how several drops of Lugol's Solution per day served as an inexpensive source of dietary iodine. Commenters detailed multiple uses for Lugol's Solution and expressed concerns that such material should remain available to end users in small quantities.
In response to comments, DEA conducted further review of the LEGITIMATE USES FOR LUGOL'S SOLUTION. These uses include (1) the staining of slides in microbiology, (2) the staining of cervical and esophageal tissue in diagnosis of disease, (3) use in aquariums, (4) use in pre-treating the thyroid gland prior to ingestion of radiolabeled I131 so that the thyroid gland will not take up large quantities of radioactive material, (5) USE AS A DIETARY SOURCE OF IODINE, and (6) use in educational science test kits for identification of starches. For each of these uses, the quantities of Lugol's Solution needed are small. In most cases, the Lugol's Solution is used in small 8 milliliter (ml) bottles or in one-fluid-ounce (30 ml) bottles. BECAUSE OF THE NUMEROUS LEGITIMATE USES AND SMALL QUANTITIES INVOLVED, DEA IS ADDING A PROVISION TO THIS FINAL RULE THAT WILL EXEMPT LUGOL'S SOLUTION WHEN PACKAGED IN BOTTLES/CONTAINERS OF ONE-FLUID-OUNCE (30 ML) OR SMALLER, AND INVOLVE DISTRIBUTION OF ONLY A SINGLE PACKAGE PER TRANSACTION. WHILE THIS FINAL RULE PROVIDES AN EXEMPTION FOR LUGOL'S SOLUTION WHEN PACKAGED IN SMALL BOTTLES, LARGER PACKAGES ARE SUBJECT TO REGULATORY CONTROLS. DEA IS AWARE OF THE AVAILABILITY OF 16 FLUID OUNCE BULK PACKAGES OF LUGOL'S SOLUTION. THESE LARGER BULK PACKAGES ARE SUBJECT TO REGULATORY CONTROL PROVISIONS INCLUDING REGISTRATION, IMPORT/EXPORT NOTIFICATION, AND RECORDKEEPING.
DEA review indicates that only 2-6 drops a day of Lugol's Solution are used for nutritional purposes. Additionally, the quantities used in the healthcare field, microbiology, and in the testing of starches, require only very small amounts of Lugol's Solution and the sale of 8 ml and one-fluid-ounce (30 ml) bottles is common. When used in an aquarium, the labeled directions indicate that only 1 drop of Lugol's Solution per 25 gallons should be used weekly. Therefore, one-fluid- ounce package of Lugol's Solution should be adequate for most legitimate purposes. A one-fluid-ounce (30 ml) package size contains 1.5 grams of iodine and has potential utility for use in the illicit manufacture of methamphetamine. Therefore, DEA is adding the provision to exempt individual transactions involving one one-fluid-ounce (30 ml) package/bottle. Individuals that distribute more than one package/ bottle of Lugol's Solution (of any size) per transaction, are subject to CSA recordkeeping and import/export requirements.
This final rulemaking includes a waiver of the registration requirement under 21 CFR 1309.24 for "Lugol's Solution (consisting of 5 percent iodine and 10 percent potassium iodide in an aqueous solution) in original manufacturer's packaging of one-fluid-ounce (30 ml) or less per package.'' Additionally, this rulemaking includes an exclusion from the definition of regulated transaction under 21 CFR 1310.08 for "Domestic and international transactions of Lugol's Solution (consisting of 5 percent iodine and 10 percent potassium iodide in an aqueous solution) in original manufacturer's packaging of one-fluid-ounce (30 ml) or less, and no greater than one package/bottle per transaction.''
DEA currently has no evidence that Lugol's Solution is diverted as a source of iodine for illicit purposes. However, should clandestine laboratory operators begin to exploit the exemption for small packages of Lugol's Solution as a source of iodine for the manufacture of methamphetamine, DEA may remove these exemption provisions.
One comment received from a physician expressed concerns regarding the possible control of an iodine product (Iodoral) that contains 5 milligrams iodine and 7.5 milligrams potassium iodide per tablet. The physician stated that this product is used in patients with thyroid disease and therefore requested that this product remain exempt from CSA regulatory provisions. In response to this comment, DEA obtained samples of Iodoral and determined that the concentration of iodine in the product is below the 2.2 percent concentration level for chemical mixtures as specified in 21 CFR 1310.12. Therefore, Iodoral 5 mg tablets are not subject to CSA regulatory control provisions following implementation of this final rule.[...]Iodine Products Subject to This Final Rule
Iodine is important to the chemical and allied industries primarily as a chemical intermediate used to make new chemical products for industry and research. These products have application in sanitation (as disinfectants), animal feed, pharmaceuticals, as catalysts, heat stabilizers, and in various other industrial applications. Most iodine is consumed by industry. Those who purchase iodine for end use, whether they are individuals or businesses, will be subject to CSA chemical regulatory controls to the extent that they must present identification and provide other information that helps assure the seller that the end user's proposed use of the chemical is legitimate. See 21 U.S.C. 830 and 21 CFR 1310.07.
Iodine has powerful bactericidal action and is used for disinfecting unbroken skin before surgery. Iodine may also be employed as a weak solution for the first-aid treatment of small wounds and abrasions.
Concentration of Iodine in Products per 100 ml: [Iodine (gm.)/Sodium iodide (gm.)/Potassium iodide (gm.)] Iodine Topical (w/water) 1.8-2.2/2.1-2.6/0.0 Strong Iodine (w/water) 4.5-5.5/0.0/9.5-10.5
Source: U.S. Pharmacopoeia (U.S.P.)
As shown in the table, the solutions are formulated in two concentrations of iodine. They are specifically named as iodine topical solution [although this is not regulated, good luck finding any of the genuine article] and strong iodine solution. Iodine topical solution two percent U.S.P. is defined as having in each 100 ml, not less than 1.8 grams and not more than 2.2 grams of iodine, and not less than 2.1 grams and not more than 2.6 grams of sodium iodide in water. Strong iodine solution U.S.P. contains in each 100 ml, not less than 4.5 grams and not more than 5.5 grams of iodine and not less than 9.5 grams and not more than 10.5 grams of potassium iodine.[...]Iodine two percent tincture and solution U.S.P. are sold at a wide variety of retail outlets and have household application as antiseptic and antimicrobial products. These products are not subject to this regulation. In contrast, iodine crystals and iodine chemical mixtures containing over 2.2 percent iodine have no household use
[[Page 35924]]
and are available only from specialty retailers. Iodine solutions (in excess of 2.2 percent iodine) are used as an antiseptic in the care of livestock and horses and as disinfectants for equipment and areas where livestock are kept. Some iodine solutions (e.g., Lugol's Solution) are used in saltwater aquariums, used as a dietary source of iodine, used to test for the presence of starch, and as stains in some laboratory tests. This rulemaking exempts small transactions of these chemical mixtures, as discussed elsewhere in this rule.
Iodine crystals have also been historically used by campers to purify water. Today, however, most of the water treatment products available to campers use iodide salts and are not the subject of this regulation. DEA, however, has identified two marketed products that contain iodine for water purification. Under this rulemaking, these products will be subject to control.
Iodine Products Not Regulated Under This Rulemaking
There are other iodine-containing products that have household use and are widely sold in retail settings. Iodine products classified as iodophors consist of iodine complexed with surfactant compounds (e.g., poloxamer-iodine complex) or with nonsurfactant compounds (e.g., polyvinyl pyrrolidone-iodine complex (povidone-iodine)). These complexes allow the iodine to be delivered continuously. Such complex solutions in water or alcohol are better tolerated than iodine tincture and solutions with comparable efficacy. Considering the necessary time of application and the correct dilution, these complexes are used for general disinfection, hand disinfection, as well as for skin disinfection prior to surgery or venipuncture. Some of these iodine complexes are also used for the treatment of burns and of different skin lesions. Since these complex products do not have applicability as a source of iodine at clandestine drug laboratories, DEA is exempting these products in 21 CFR 1310.12(d)(4). This provision will automatically exempt from CSA controls "Iodine products classified as iodophors, which exist as an iodine complex to include poloxamer-iodine complex, polyvinyl pyrrolidone-iodine complex (i.e. povidone-iodine), undecoylium chloride iodine, nonylphenoxypoly (ethyleneoxy) ethanol- iodine complex, iodine complex with phosphate ester of alkylaryloxy polyethylene glycol, and iodine complex with ammonium ether sulfate/ polyoxyethylene sorbitan monolaurate.''
Additionally, DEA wishes to clarify that organically bound iodine products that are non-ionic complexes (e.g., iopamidol, iohexol and amiodarone) are not subject to CSA regulatory controls. These organically bound compounds cannot serve as a source of iodine for methamphetamine laboratories and therefore are not at risk of diversion. As clarification, DEA has added a new paragraph under 21 CFR 1310.12(d)(5), which specifies that "Iodine products that consist of organically bound iodine (a non-ionic complex) (e.g., iopamidol, iohexol, and amiodarone)'' are chemical mixtures that are automatically exempt from CSA regulatory provisions.
This rulemaking implements regulatory controls that apply to iodine crystals and iodine chemical mixtures that contain greater than 2.2 percent iodine. The vast majority of products having household application are not adversely impacted by this regulation.[...]Since seven percent iodine tincture and solutions are the predominant iodine-containing chemical mixtures diverted by traffickers, DEA has determined that these chemical mixtures should be subject to CSA chemical regulatory controls. Two percent iodine tincture and solutions are also diverted, but DEA has not documented the frequent diversion of these materials at clandestine laboratories. Therefore, DEA is not regulating the two percent iodine tincture or solution at this time.[...]Any chemical mixture that is regulated because it contains greater than 2.2 percent iodine is treated as a List I chemical [i.e. a chemical which is important in the manufacture of meth, for example]. Therefore, the same requirements for registration, records and reports, imports/ exports, and administrative inspection, as outlined below, apply to handlers of regulated chemical mixtures.