Is povidone iodine flammable? (A Comprehensive Overview)

This article will answer the following question: “Is povidone iodine flammable?”. We will discuss what povidone-iodine is, the dangers of using it, and how flammable the compound can be or not.

Is povidone iodine flammable?

No. Povidone-iodine solutions normally can’t catch fire. The active ingredient itself is barely combustible, so it’s not flammable either. Some povidone solutions, although, may contain ethanol, which is very flammable. 

But in this case, the compound is named tincture of iodine. The whole point of creating a complex compound between povidone and iodine is to make iodine water-soluble.

What is povidone iodine?

Also called polyvidone, iodopovidone, and PVP-I, it is a water-soluble polymer made with complexation between Polyvinylpyrrolidone (PVP) and iodine.

It is used as an antiseptic, mainly to treat and prevent skin infections, before and after surgeries. Many health professionals use it to disinfect their hands.

Iodopovidone is a chemical complex, made of elemental iodine, hydrogen iodide, and povidone. Povidone-iodine is a more specific kind of iodophor.

What are PVP-I products made of?

PVP iodine is a solution containing elemental iodine, hydrogen iodide, and povidone.

The solutions often present a yellow-brownish color and often present a strong and unpleasant smell.

Iodine itself doesn’t mix with water very well, so other solvents and complexants are required so we can have a liquid solution that can be easily applied.

Iodine is commonly complexed using an organic molecule that acts like a carrier, typically a water-soluble polymer. One of these molecules is the PVP.

One of the most common forms of iodophor is a solution with Polyvinylpyrrolidone (PVP), complexed with between 9% and 12% iodine. 

PVP itself doesn’t present toxicity to cells. It can be taken orally and would pass through our bodies unchanged unless one is allergic to it.

Besides solubilizing iodine, the polymer reaches a chemical equilibrium that allows some concentration of free iodine to be available in the solution at all times, which enhances sanitizing effects.

But what is iodine?

Iodine is a chemical element that can be found in the periodic table.

It’s a halogen, a member of group 17. It’s the heaviest member of its group, and coincidently the heaviest essential mineral nutrient for mammals, including us.

It exists in many forms. We usually don’t encounter it in its pure form (called primordial), only in salts or in a liquid solution. 

Commercially available forms of iodine are not pure forms of it, but primordial iodine might be mixed with them.

Iodine is solid and has the formula I2 in its pure crystalline form, but it can also exist as gas and present the same formula. There are also other forms: Iodide (I), triiodide (I3), iodate (IO3), some kinds of acid, and periodate anions (IO4, IO6−5, and others).

Iodine’s primary use is in our nutrition. We require Iodine in our bodies so it can synthesize thyroid hormones. The lack of it may lead us to disinvolve goiter and prejudice the central nervous system development in fetuses and infants.

Knowing that iodine deficiency is prejudicial, many governments oblige manufacturers to supplement table salt with iodine. 

About 88% of all households worldwide use iodized table salt, but it’s still a problem in some underdeveloped countries.

Some forms of salts considered gourmets, such as Himalayan Pink Salt, Kosher salt, Smoked salts, and others, may not have iodide added to their formulation.

Industrially, the iodide anion is used as a catalyst in the production of acetic acid, and in organic chemistry to synthesize certain polymers.

Povidone-iodine properties, chemistry, and discussion

PCP-I is a chemical complex. The iodine is actually in the form of a triiodide (I3), which bonds with a polyvinylpyrrolidone, a polymer that has a positive electrical charge.

The “n” and “m” letters indicate a number. Polymers are compounds made of smaller units that repeat themselves.

You may be wondering why having all this trouble connecting PVP to iodine. After all, it’s the Iodine that has disinfectant action, povidone practically does nothing to anyone.

The answer lies in the iodine properties. Elemental iodine (I2, the pure form) is water-soluble. But it’s much easier for us to use water solutions because it’s easier to dilute them.

So, we must before forcing iodine to become soluble. This can be done by complexing it with another water-soluble compound, among other ways. But why a polymer?

Besides the price, polymers like this can hold, contain and restrain that positive electrical charge you can see from the image, stabilizing it. 

This means that PVP can be happy by either staying bonded with I3 (which neutralizes the charge) or remaining with the positive charge (which is the absence of two electrons). This helps liberate I3 in water, the active ingredient that allows disinfection.

How does povidone work?

Povidone-iodine is a sanitizing agent. Its antimicrobial action allows direct effects on cells, disturbing protein synthesis, eventually leading to cell death.

The antimicrobial action of iodine is certain, but its specific mode of action is unknown. We can assume that it attacks some amino acids, nucleotides, and fatty acids, preventing peptide synthesis (protein synthesis) and resulting in cell death.

Iodine and PVP are widely used worldwide as antiseptics. Its medicinal use is so important that it is part of the World Health Organization’s List of Essential Medicines.

Is povidone iodine flammable? 

No. Povidone-I is normally water-based and presents no flammability.

Povidone-iodine solutions are normally made of an acid diluted in water, such as Hydriodic acid and Phosphoric Acid, but might also contain organic compounds such as nonylphenol.

Although, we couldn’t find any PVP-I solution that presents any flammability because the major constituent is always water.

But you can’t let your guard down. Some products may present different names that make us incorrectly believe that the solution is for one kind of iodine compound, instead of another.

There are other iodine products such as iodine tincture that have alcohol in their formulation instead of water, making them very flammable.

Is iodophor the same as povidone iodine?

Not exactly. They both have the same properties, but iodophor doesn’t necessarily have the same ingredients as povidone-iodine.

Povidone-iodine can be considered as a type of iodophor, but not the other way around.

Povidone-iodine is a complexation between iodine and a water-soluble polymer, but some iodophors don’t have polymers added to their formulation.

Is povidone iodine the same as tincture of iodine?

Not exactly. Their uses are similar, but can’t be considered synonyms. 

Povidone-iodine is an aqueous and acidic solution that has iodine as the active ingredient. 

The tincture of iodine also has the same active ingredient, but the rest of the solution is different. Iodine tincture is composed of ethanol, potassium iodide, and sodium iodide as well.

Because of that, the tincture of iodine is normally flammable, while the other forms of antiseptic iodine are not. There’s also a similar compound called Lugol’s iodine, which doesn’t have ethanol added.

Is povidone toxic?

Povidone itself is generally considered safe by the U.S. Food and Drug Administration (FDA).

Although, there have been a few cases of reaction to PVP-Iodine in people that, later on, were recognized as allergic to PVP. 

These people had a predisposition for allergies, and the compound was only toxic because it was taken orally. No toxicity is expected for those who use it topically according to label instructions.

Overall, povidone-iodine is safe to be used topically, following all the instructions available on the label and other safety instructions such as Safety Data Sheets and Material Safety Data Sheets.

Safety data sheets

You can check further information in the product’s safety data sheets.

  • This one contains 100% PVP-I;
  • This is a similar one, from another laboratory;
  • This is from Pfizer. It has some different ingredients, but no flammability;
  • Povidone-iodine 10% topical solution.

Conclusion

Povidone-iodine is not considered flammable according to both product safety data sheets provided by the manufacturers, and judging according to the chemical compound alone.

Frequently Asked Questions (FAQS): Is povidone iodine flammable?

is povidone iodine the same as betadine?

Well, yes. Betadine is the brand name for a povidone-iodine topical solution that works as a disinfectant.

is povidone iodine antiseptic?

Yes. It has antiseptic properties. PVP-I can suppress the formation of certain proteins in the cells of many types of microorganisms, leading them to death, hence presenting disinfection properties.

At the same time that the compound can treat our wounds, it also doesn’t impede our cells from healing.

is povidone iodine safe for cats?

Yes. Povidone-iodine is safe for the treatment of minor skin wounds in cats. The same compound is used by veterinarians to wash and sanitize their hands and arms before and after the surgeries.

Medics also use the compound for the same purposes.

Citations

https://en.wikipedia.org/wiki/Iodine
https://en.wikipedia.org/wiki/Iodophor
https://en.wikipedia.org/wiki/Povidone-iodine#/media/File:Povidone-iodine.svg
https://en.wikipedia.org/wiki/Polyvinylpyrrolidone
https://pubchem.ncbi.nlm.nih.gov/compound/410087
https://www.lernapharm.com/msds/msds_pvp-i.pdf
https://cdn.pfizer.com/pfizercom/products/material_safety_data/PZ00714.pdf
https://www.humco.com/wp-content/uploads/2019/03/2325-Povidone-Iodine-10-SDS.pdf
https://pubchem.ncbi.nlm.nih.gov/compound/410087

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