SODIUM PYRITHIONE
SODIUM PYRITHIONE
Sodium Pyrithione = Sodium Omadine = Natrium-Pyrion = sodium;1-oxidopyridine-2-thione = NaPT
CAS number: 3811-73-2
EINECS number: 223-296-5
EC / List no.: 240-062-8
Molecular Fomula: C5H4NNaOS
Molecular weight: 149.15
Sodium Pyrithione is an antimicrobial agent suitable for use in marine paints, aerosols, and metal working fluids.
Sodium Pyrithione is used for shampoo to dandruff.
Sodium Pyrithione has the characteristics of high efficiency, broad spectrum, low toxicity and stable aqueous solution.
The main application areas of Sodium Pyrithione include: daily chemical products, adhesives, paper, medicine, pesticides, leather products, disinfection products.
Sodium Omadine is a zero-VOC solution of the trusted antimicrobial sodium pyrithione, and can effectively inhibit the growth of bacteria and fungi in a wide variety of household products in areas such laundry care, surface cleaning and aircare.
Antimicrobial preservative (sodium pyrithione) used in a variety of water-based functional fluids and coatings to protect against micro-organisms.
Sodium Pyrithione inhibits the growth of fungi, yeast, mold and bacteria.
Sodium Pyrithione is used in formulating anti-microbial property in paint, sealants, shampoo, adhesive and aerosol.
Amine N-oxides are active components in body care products such as shampoo, bubble bath, and hand-soap formulations as they are cationic and can act as a mild conditioner in acidic media.
In neutral or weak basic media, they are featured as excellent stabilizer and viscosity building provider.
Pyrithione sodium (2-mercaptopyridine N-oxide) is a biocide with a broad spectrum of activity against fungi, Gram-positive and Gram-negative bacteria.
Pyrithione has been used to study its efficacy in picornavirus infections.
Sodium Pyrithione is considered a dangerous good.
Quantities above 1 g may be subject to additional shipping fees.
Sodium Pyrithione Used as
-biocide (controls slime forming bacteria and fungi) in aqueous functional fluids (metalworking, cutting, cooling, and lubricating),
-latex emulsions (adhesives, caulks, patching compounds, sealants, pastes, and grouts),
-aqueous fiber lubricants and inks, jet-printer inks, laundry rinse additives and detergents, carpet cleaners, analytical and diagnostic reagents;
Also used as in-can preservative for water based mixtures used in making concrete (not covered in this RED)
Applications of Sodium Pyrithione:
2-Mercaptopyridine N-oxide sodium salt is one of the active components in paint, sealants, shampoo, adhesive and aerosol due to its anti-microbial activity.
In biochemistry studies, Sodium Pyrithione is utilized to transport zinc into cells.
Further, Sodium Pyrithionet is used to form bidentate oxothiolane chelates with transition metals.
Sodium Pyrithione acts as a stabilizer and viscosity building provider in weak basic or neutral medium.
Sodium Pyrithioneis widely used preservative for water based metal working fluids and as mold and midewcide in gypsum boards.
Sodium Pyrithiones activity spectrum provides for control of fungal growth.
Sodium Pyrithione is a highly effective microbiocide even at very low usage levels.
Sodium Pyrithiones functions (INCI)
Preservative : Inhibits the development of microorganisms in cosmetic products.
Antimicrobial efficacy:
Kopthione Na 40% FPS possesses a broad spectrum of antifungal and antialgal activity against all fungi and algae including following relevant organisms.
Application and recommended Dosage:
Sodium Pyrithione Used as biocide in aqueous functional fluids, latex emulsions, aqueous fibre lubricants and inks, jet printer inks, laundry rinse additives and detergents, carpet cleaners, analytical and diagnostic reagents.
Sodium Pyrithione Also used as in can preservatives for water based mixtures used in making concrete.
Usage of Sodium Pyrithione:
Oil Drilling Auxiliary Agent, Water Treatment Chemicals, Rubber Auxiliary Agents, Plastic Auxiliary Agents, Coating Auxiliary Agents, Textile Auxiliary Agents, Paper Chemicals, Surfactants, Leather Auxiliary Agents, Electronics Chemicals
Application sites: In metal working fluids, paints, inks, adhesives, plastics, laundry rinse additives, polymers and floor finishes.
Types and method of application:
For manufactured materials to add at any point during the manufacturing process.
As a preservative add directly to the solution to be preserved.
Addition and compatibility:
Sodium Pyrithione is stable under normal environmental conditions if stored in closed, dark containers.
At 100 C Sodium Pyrithione is stable for 24 hours.
In the light or in contact with weak oxidizing agents sodium Pyrithione is converted to the disulfide; 2,2 –pyridyl-N-oxide disulfide.
With stronger oxidizing agents or in alkaline solution the substance is converted via a number of intermediatesto the sulfonic acid.
Chemical Properties:
Clear solution
Uses:
For chemistry of 2-mercaptopyridine-N-oxide, see Aldrichimica Acta.1
Uses:
sodium pyrithione is a preservative that is not commonly used because of some level of toxicity.
Sodium Pyrithione is prohibited in Canada, and Sodium Pyrithione is on the eu Annex II list of substances that must not form part of a cosmetic product composition.
Uses:
Sodium omadine is a bactericide for use in cooling fluids and short-term in-can preservation of vinyl acetate latex, paints, and synthetic-fiber lubricants; preservative for cosmetic rinse-off products.
Definition:
Apparently exists in equilibrium with the -SH form.
Forms chelates with iron, manganese, zinc, etc.
Safety Profile:
Poison by intraperitoneal and intravenous routes.
Moderately toxic by ingestion, subcutaneous and parenteral routes. Used in preservation of cosmetics.
When heated to decomposition it emits very toxic fumes of Na2O, NOx, and SOx.
Sodium Pyrithione Fungicide is a highly active, broad-spectrum antimicrobial agent that, when used at recommended concentrations, can help to prevent and minimize problems associated with fungal contamination.
Sodium Pyrithioneis the 40% aqueous sodium salt derivative of pyrithione
Stability:
Sodium Pyrithione, at room temperature in the dark, sodium pyrithione is stable in the pH range 4.5 to 9.5.
At 100°C Sodium Pyrithione is stable for at least 120 hours, at 150°C 29 % of the substance has decomposed within 48 hours.
In the light or in contact with weak oxidizing agents sodium pyrithione is converted to the disulfide, 2,2-pyridyl-N-oxide disulfide.
With stronger oxidizing agents or in alkaline solution (pH > 9.5) the substance is converted via a number of intermediates to the sulfonic acid; the reaction with reducing agents yields thiopyridine.
Production:
reaction of 2-bromopyridine with peracetic acid to yield 2-bromopyridine oxide which is reacted with thiourea and then converted to the sodium salt
Sodium Pyrithione Uses:
Sodium pyrithione is used as a broad spectrum biocide especially against fungi and gram positive and gram negative bacteria in metal-working fluids (boring and cutting oils, up to 0.5 % in the concentrate).
Sodium Pyrithione used in the rubber industry and paint industry (dispersion paints, 0.05 %–0.2 %) and in cosmetics which are rinsed off, such as shampoos and wash lotions for the skin, in concentrations of 0.5%.
Product Name: Sodium Pyrithione
Chemical Names: Sodium pyrithione; Omadine sodium; Omadine-sodium; Omacide 24; Caswell No. 790A; 2(1H)-Pyridinethione, 1-hydroxy-, sodium salt; Sodium omadine (TN); 2-Pyridinethiol, 1-oxide, sodium salt
Molecular Formula: C5H4NNaOS
Molecular Weight: 149.143 g/mol
IUPAC Name: sodium;1-oxidopyridine-2-thione
CAS Number: 15922-78-8
Parent Compound: Pyrithione zirconium (CID 19659)
Appearance: Clear, yellow-brown liquid
Melting Point: -25°C
Boiling Point: 105°C
Solubility: Soluble in water
NaPT is amber color, clear, 40% aqueous solution of Sodium Pyrithione.
Metalworking fluids are breeding grounds for microorganisms, particularly bacteria and fungi.
It degrades fluid performance and damages all associated work pieces, tool etc, while can also cause allergies and skin problems in workers.
Jubithione NaPT is an effective anti-microbial solution to these problems.
CHEMICAL REACTIVITY
Oxidizing agents (such as peroxides and hypohalites) will convert pyrithione first to dipyrithione (2,2′-dithiobis-pyridine-1, 1′- dioxide), which is microbiologically active, and finally to pyrithione sulfinic or sulfonic acid, which are not microbiologically active compounds.
Strong reducing agents will react with the N-oxide group of pyrithione to give 2-mercaptopyridine or its derivatives.
These compounds are much less microbiologically active than the parent compound.
GENERAL DESCRIPTION OF PYRIDINETHIONE
Pyridinethione inhibits the growth of fungi, yeast, mold and bacteria.
Sodium and zinc salt of pyrithione N-oxide are widely used in cosmetics and shampoo.
In acidic media, amine N-oxides are cationic and can act as a mild conditioner.
Sodium Pyrithione is used in body care products.
Pyridinethione derivatives, belong to a class of cyclic sulfur organo products containing sulfur atom (S) and often oxygen (O), nitrogen (N), hydrogen (H), as well as other elements, can find application for making biologically active agents such as antiviral, antibacterial, antifungal , antituberculous, antbody and antifungal agents.
Pyrimidine is a heterocyclic compound containing nitrogen atoms at positions 1 and 3 in six-membered ring structure molecule.
The three major pyrimidines in living systems are cytosine, thymine, and uracil.
Pyrimidine and its derivatives are biologically important components of nucleic acids (DNA, RNA) and coenzymes.
Sodium Pyrithione can be the parent compound of many drugs, including the barbiturates.
Analytical METHODS
Analytical procedures are available on request for the products as sold and for determining concentrations in metalworking fluid formulations.
APPLICATIOn
For product application and formulation information please refer to SODIUM OMADInE 2000 Antimicrobial product labeling.
Assay: ≥40%
Appearance: Light Yellow Liquid
Package: Net 250kg/drum or 25kg/drum
Capacity: 600MT/year
Sodium Pyrithione is a proprietary blend based on the antimicrobial active, sodiumpyrithione (CAS # 3811-73-2) a fungicidal product with a successful history of use by the metalworking industry.
Sodium Pyrithione exhibits increased efficacy against a wide variety of microorganisms found in metalworking fluid systems.
In addition to its anticipated antifungal performance, Sodium Pyrithione also exhibits antibacterial efficacy.
The improved antimicrobial performance of SODIUM OMADInE 2000 Antimicrobial is not a result of combinations with formaldehyde-based condensates, phenols, or isothiazoline-based products.
This proprietary product is a blend of sodium pyrithione with a potentiator, and an amine coupler.
This versatile antimicrobial blend can eliminate the need for formulating with multiple products.
Sodium Pyrithione provides broad-spectrum antimicrobial control to a variety of metalworking fluid formulations and is suitable for use in both metalworking fluid concentrates and as a post treatment additive.
Sodium Pyrithione is registered for use with the United States Environmental Protection Agency (US EPA Reg. No. 1258-1238) under the Federal Insecticide,
Fungicide and Rodenticide Act (FIFRA), for use in metalworking, cutting, cooling and lubricating concentrates and end-use fluids.
If you are considering another use of Sodium Pyrithione, please consult with an Arch Chemicals, Inc. representative.
Sodium Pyrithione is a violation of Federal law to use an antimicrobial agent in an application for which it does not have EPA registration.
Melting point: 252–257°C (decomposes)
Density at 25°C: 1.167 gm/cm3
Solubility (g/100 g at 25°C):
water (53)
ethanol (19)
propylene glycol (13)
polyethylene glycol 400 (12)
dimethyl sulfoxide (17)
liquid paraffin (< 0.0001)
olive oil (< 0.0005)
Purity/impurities : commercially available as a powder (technical grade, purity 90–95 %) or as a 40–45 % aqueous solution (pH 9.2 at 25°C)
In case of skin contact : Take off contaminated clothing and shoes immediately.
Wash off immediately with plenty of water for at least 15 minutes.
If a person feels unwell or symptoms of skin irritation appear, consult a physician.
Wash contaminated clothing before re-use
In case of eye contact : Rinse immediately with plenty of water for at least 15 minutes.
Keep eye wide open while rinsing.
Immediate medical attention is required.
If swallowed : Do NOT induce vomiting.
Never give anything by mouth to an unconscious person.
If you feel unwell, seek medical advice (show the label where possible).
Suitable extinguishing media : Use extinguishing measures that are appropriate to local circumstances and the surrounding environment.
Carbon dioxide (CO2)
Water spray
Unsuitable extinguishing media : Do NOT use water jet.
Specific hazards during firefighting : The product is not flammable.
Do not allow run-off from fire fighting to enter drains or water courses.
Burning produces noxious and toxic fumes.
What else is Sodium omadine called?
This chemical can be identified by different names, including:
2‐Mercaptopyridine‐N‐oxide, sodium salt
2‐Pyridinethiol‐1‐oxide, sodium salt
Mercaptopyridine‐N‐oxide sodium salt
N‐Hydroxy‐2‐pyridinethione, sodium salt
Sodium‐2‐pyridinethiol‐1‐oxide
sodium pyrithione
Sodium pyrithione is a fungistatic and antimicrobial derivative of aspergillic acid.
Although the exact mechanism of action remains to be fully elucidated, Sodium pyrithione appears to interfere with membrane transport ultimately leading to a loss of metabolic control.
Absorption
Following oral ingestion, only the Sodium pyrithione moiety is absorbed.
Less than 1% of administered zinc Sodium pyrithione is absorbed from the skin [L1758].
Radioabeled Zn Sodium pyrithione administered to rats, rabbits and monkeys, either orally or via intraperitoneal injection were absorbed into circulatin to extent of 80-90% [L1758].
Inhibition of fungal growth by Sodium pyrithione zinc is linked to increased copper uptake and cellular levels of copper, which is demonstrated by decreased CTR1-lacZ expression and slightly increased CUP1-lacZ expression in affected microorganisms [A32162].
The coordination complex of Sodium pyrithione zinc dissociates, and Sodium pyrithione ligand forms a CuPT complex from available extracellular copper in the target organism.
Sodium pyrithione acts as an ionophore, interacting nonspecifically with the plasma membrane to shuttle copper into the cell, and facilitates copper transport across intracellular membranes [A32162].
Copper may be shuttled into the mitochondria.
Copper inactivates iron-sulfur (Fe-S) cluster-containing proteins via a mechanism similar to that described for copper-induced growth inhibition in bacteria [A32162].
Decreased activity of Fe-S proteins leads to inhibition of fungal metabolism and fungal growth.
Sodium pyrithione zinc has been shown to slightly increase the levels of zinc [A32162].
Sodium pyrithione (or pyrithione zinc) is a coordination complex of zinc.
Sodium Pyrithione has fungistatic (that is, it inhibits the division of fungal cells) and bacteriostatic (inhibits bacterial cell division) properties and is used in the treatment of seborrhoeic dermatitis.
Structure of the compound
The pyrithione ligands, which are formally monoanions, are chelated to Zn2+ via oxygen and sulfur centers.
In the crystalline state, Sodium pyrithione exists as a centrosymmetric dimer (see figure), where each zinc is bonded to two sulfur and three oxygen centers.
In solution, however, the dimers dissociate via scission of one Zn-O bond.
Sodium Pyrithione was first described in the 1930s.
Pyrithione is the conjugate base derived from 2-mercaptopyridine-N-oxide (CAS# 1121-31-9), a derivative of pyridine-N-oxide.
Uses of Sodium Pyrithione
Medical
Sodium pyrithione can be used to treat dandruff and seborrhoeic dermatitis.[medical citation needed]
Sodium Pyrithione also has antibacterial properties and is effective against many pathogens from the Streptococcus and Staphylococcus genera.
[medical citation needed] Its other medical applications include treatments of psoriasis, eczema, ringworm, fungus, athletes foot, dry skin, atopic dermatitis, tinea versicolor, and vitiligo.
In paint
Due to its low solubility in water (8 ppm at neutral pH), Sodium pyrithione is suitable for use in outdoor paints and other products that provide protection against mildew and algae.
Sodium Pyrithione is an effective algaecide.
Sodium Pyrithione is chemically incompatible with paints relying on metal carboxylate curing agents.
When used in latex paints with water containing high amount of iron, a sequestering agent that will preferentially bind the iron ions is needed.
Sodium Pyrithiones decomposition by ultraviolet light is slow, providing years of protection even against direct sunlight.
In sponges
Sodium pyrithione is also used as an antibacterial treatment for household sponges, most notably by the 3M Corporation.
In clothing
A process to apply Sodium pyrithione to cotton with washable results was patented in the United States in 1984.
Sodium pyrithione is now used to prevent microbe growth in polyester.
Textiles with applied Sodium pyrithione protect against odor-causing microorganisms.
Export of antimicrobial textiles reached US$497.4 million in 2015.
Mechanism of action
Sodium Pyrithiones antifungal effect is thought to derive from Sodium Pyrithiones ability to disrupt membrane transport by blocking the proton pump that energizes the transport mechanism.
Health effects
Sodium pyrithione is approved for over-the-counter topical use in the United States as a treatment for dandruff and is the active ingredient in several antidandruff shampoos.
In Sodium Pyrithiones industrial forms and strengths, Sodium Pyrithione may be harmful by contact or ingestion.
Sodium pyrithione can trigger a variety of responses, such as DNA damage in skin cells.
Sodium pyrithione is the sodium salt form of pyrithione, a fungistatic and antimicrobial derivative of aspergillic acid.
Although the exact mechanism of action remains to be fully elucidated, Sodium pyrithione appears to interfere with membrane transport ultimately leading to a loss of metabolic control.
Metalworking fluids are fertile breeding grounds for microorganisms, particularly bacteria and fungi.
Their unchecked growth causes fluids to deteriorate and degrades the fluid performance; this in turn causes damage to the work piece, cutting tools and fluid handling systems.
Growth of microorganisms in fluids can also affect workers by causing foul odors, skin irritation and allergic reactions. These problems can be reduced or eliminated through the proper use of an antimicrobial agent.
Sodium Pyrithione is a proprietary blend based on the antimicrobial active, sodium pyrithione (CAS # 3811-73-2) a fungicidal product with a successful history of use by the metalworking industry.
Sodium Pyrithione exhibits increased efficacy against a wide variety of microorganisms found in metalworking fluid systems.
In addition to Sodium Pyrithiones anticipated antifungal performance, Sodium pyrithione 2000 Antimicrobial also exhibits antibacterial efficacy.
The improved antimicrobial performance of Sodium pyrithione 2000 Antimicrobial is not a result of combinations with formaldehyde-based condensates, phenols, or isothiazoline-based products.
Sodium Pyrithione is a blend of sodium pyrithione with a potentiator, and an amine coupler. This versatile antimicrobial blend can eliminate the need for formulating with multiple products.
Sodium Pyrithione provides broad-spectrum antimicrobial control to a variety of metalworking fluid formulations and is suitable for use in both metalworking fluid concentrates and as a post treatment additive.
Addressing the blue color problem
Metalworking fluids have been known to change color upon the addition of pyrithione-based biocides.
Sodium Pyrithione is often referred to as the ‘blue-color problem’.
Sodium Pyrithione color change is due to the presence of ionic iron, which combines with pyrithione to form a highly colored, water insoluble compound.
Iron can be introduced through raw materials, dilution water, or certain metalworking fluid operations.
In the case of metalworking fluid concentrates, while the levels of ionic iron present are usually low, typically in the range of 5-25 ppm (parts per million), addition of sodium pyrithione will discolor the formulation, turning it gray or at times black.
One method for addressing this problem is through the use of iron specific sequestering agents, like ethylenediaminetetraacetic acid (EDTA) or Arch’s Wayhib RW Chelating Agent.
A more chronic problem for pryithione-based biocides is with high-speed cast iron machining operations.
Metalworking fluid formulations used in these operations tend to accumulate and maintain high levels of ionic iron, making the use of sodium pyrithione unsuitable.
In controlled laboratory tests dilute metalworking fluids known to contain 100-150 ppm of ironic iron did not discolor. In addition, this proprietary new antimicrobial can be used in formulations, which accumulate and maintain high levels of iron, while in use.
Additions of Sodium pyrithione 2000 Antimicrobial to dilute metalworking fluids known to contain ionic iron in the range of 100-150 ppm did not turn blue, and the antimicrobial performance remains intact.
Below is a summary of data obtained using a test designed to evaluate the effectiveness of Sodium pyrithione 2000 Antimicrobial in three types of metalworking fluid formulations.
The test protocol calls for one hundred milliliters of appropriately diluted fluid (20:1) to be placed into two hundred fifty milliliter Erlenmyer flasks.
Sodium pyrithione 2000 Antimicrobial is added to each flask at the onset of the experiment.
The treatment level used for this experiment was 1000 ppm, product as sold.
Flasks are maintained at ambient temperature on an orbital shaker and challenged 3 times a week with a mixed inoculum of bacteria and fungi.
RECOMMENDED USE LEVELS
The recommended use level for Sodium pyrithione 2000 Antimicrobial in metalworking fluid concentrates (typically used at 20:1) is between 2.0-4.0%, product as sold.
Post treatment dose levels of 1000-3000 ppm, product as sold, have been shown to be very effective in dilute metalworking fluids.
The Following United States EPA Guidelines Should be Followed When Using This Biocide:
TO INHIBIT THE GROWTH OF FUNGI AND BACTERIA IN
AQUEOUS METALWORKING, CUTTING, COOLING AND
LUBRICATING FLUIDS: Add up to 5000 parts per million
(0. 5% v/v) of Sodium pyrithione 2000 Antimicrobial to the diluted fluid (5.0 gals per 1000 gals).
If any of these parameters is outside the specifications established for the system in question, they should be brought up to specifications by the addition of suitable additives or the fluid should be discarded and replaced after cleaning the system.
Add Sodium Pyrithione to the fresh fluid according to the above directions.
Contaminated fluid systems should be cleaned prior to the addition of Sodium pyrithione 2000 Antimicrobial.
Drain the system, clean with a cleaner designed for this purpose, rinse with water, and refill with fresh fluid.
Sodium pyrithione 2000 Antimicrobial may be added to the fluid at the time it is prepared (diluted) or to the reservoir (sump) containing the fluid after it is put into use.
If Sodium Pyrithione is added to the reservoir, the fluid should be circulated after addition to ensure mixing.
LIGHT STABILITY
Sodium pyrithione 2000 Antimicrobial will gradually degrade when exposed to UV light.
Formulations containing Sodium pyrithione 2000 Antimicrobial should be packaged in brown or opaque containers unless tests have shown that photodegradation is not a problem.
PH STABILITY
Sodium pyrithione 2000 Antimicrobial is effective over the pH range typical of most metalworking fluids.
Below pH 4.5, the sodium salt is in equilibrium with free pyrithione and while pyrithione is microbiologically active, it is very unstable in the presence of light or oxygen.
CHEMICAL REACTIVITY
Oxidizing agents (such as peroxides and hypohalites) will convert pyrithione first to dipyrithione (2,2′-dithiobis-pyridine-1, 1′- dioxide), which is microbiologically active, and finally to pyrithione sulfinic or sulfonic acid, which are not microbiologically active compounds.
SAFETY INFORMATION
Material Safety Data Sheets containing appropriate health and safety advice on Sodium pyrithione 2000 Antimicrobial are available from your nearest regional office.
APPLICATION
For product application and formulation information please refer to Sodium pyrithione 2000 Antimicrobial product labeling.
Product Name Pyrithione sodium
CAS15922-78-8
SynonymsSodium Pyrithione
CategoryMain Products
Molecular FormulaC5H4NNaOS
Molecular Weight149.15
Physical StateSolid
Directions for Use of Sodium pyrithione
To inhibit the growth of fungi in aqueous metalworking, cutting, cooling and lubricating fluids: Add up to 1250 ppm (0.125% v/v) of Sodium pyrithione fungicide to the diluted fluid (1.25 gal per 1000 gal of solution).
Typical recommended dose levels are between 200 and 500 ppm, product as sold.
Different use and contamination conditions may require different levels of Sodium pyrithione fungicide and while compatible with most metalworking fluids physical and chemical compatibility testing is recommended.
When adding fresh diluted fluid to compensate for dragout or other losses, add Sodium pyrithione fungicide to make-up fluid according to the above directions.
Frequent checks (at least once per week) of the bacterial and fungal population in the system should be made using standard microbiological plate count procedures or any of the commercial “dip-stick” type devices.
When the fungal count reaches 102 organisms per milliliter or greater, add additional Sodium pyrithione fungicide according to the above directions.
The fluid should be checked at least once per day with a refractometer (or other suitable means) to determine if water loss by evaporation has occurred.
Make-up water should be added daily to compensate for such losses.
The fluid should be monitored at least once per week (depending on the metalworking operation involved) for the following: tramp oil, pH, odor, oil droplet size, and anticorrosion properties.
If any of these parameters is outside the specifications established for the system in question, they should be brought up to specifications by the addition of suitable additives or the fluid should be discarded and replaced after cleaning the system.
Add Sodium pyrithione fungicide to the fresh fluid according to the above directions.
Contaminated fluid systems should be cleaned prior to the addition of Sodium pyrithione fungicide.
Drain the system, clean with a cleaner designed for this purpose, rinse with water, and refill with fresh fluid.
Sodium pyrithione fungicide may be added to the fluid at the time it is prepared (diluted) or to the reservoir (sump) containing the fluid after it is put into use.
If Sodium Pyrithione is added to the reservoir, the fluid should be circulated after addition to ensure mixing.
To inhibit the growth of fungi in aqueous metalworking, cutting, cooling and lubricating concentrates:
Add an amount that will give up to 1250 ppm in the diluted fluid.
The amount required in the concentrate will depend on the end use dilution.
For example: If the desired level of Sodium pyrithione fungicide in the diluted fluid is 200 ppm, and the end use dilution of the fluid is 5%, then a 0.4% concentration of Sodium pyrithione fungicide is required in the concentrate (200 ppm/0.05 = 4,000 ppm or 0.4%).
Heat Stability of Sodium pyrithione
Sodium pyrithione fungicide is stable at 100°C for at least 120 hours.
At 150°C, the assay of Sodium pyrithione fungicide decreases 29% during a 48-hour period.
The heat of decomposition, as measured under nitrogen by differential scanning calorimetry, is 158 cal/g for Sodium pyrithione fungicide.
CAS RN3811-73-2
EC Number223-296-5
MDL NumberMFCD01941547
Storage Temperature+20°C
Shipping TemperatureAmbient
pH Stability of Sodium pyrithione
Sodium pyrithione fungicide can be used over the pH range from 4.5 to 11.0.
Below pH 4.5, the sodium salt is in equilibrium with free pyrithione.
Pyrithione is active microbiologically, but is very unstable in the presence of light or oxygen.
Light Stability of Sodium pyrithione
Sodium pyrithione fungicide will gradually degrade when exposed to light, depending on the nature of the formulation.
Formulations containing Sodium pyrithione fungicide should be packaged in brown or opaque containers unless tests have shown that photodegradation is not a problem.
Sodium pyrithione Fungicide is a highly active, broad-spectrum antimicrobial agent that, when used at recommended concentrations, can help to prevent and minimize problems associated with fungal contamination.
Sodium pyrithione is the 40% aqueous sodium salt derivative of pyrithione.
Sodium pyrithione functions as a wet-state preservative against bacteria and fungus in latex paints.
Sodium pyrithione is a highly active, very effective water soluble sodium pyrithione.
Offers pronounced growth-inhibiting activity against both yeasts and molds.
Sodium pyrithione possesses non-irritating and non-sensitizing properties.
Sodium pyrithione is the common name of an organosulfur compound with molecular formula C5H5NOS, chosen as an abbreviation of pyridinethione, and found in the Persian shallot.
Sodium Pyrithione exists as a pair of tautomers, the major form being the thione 1-hydroxy-2(1H)-pyridinethione and the minor form being the thiol 2-mercaptopyridine N-oxide; it crystallises in the thione form.
Sodium Pyrithione is usually prepared from either 2-bromopyridine, 2-chloropyridine, or 2-chloropyridine N-oxide, and is commercially available as both the neutral compound and its sodium salt.
Sodium Pyrithione is used to prepare zinc Sodium pyrithione, which is used primarily to treat dandruff and seborrhoeic dermatitis in medicated shampoos, though is also an anti-fouling agent in paints.
Preparation
The preparation of Sodium pyrithione was first reported in 1950 by Shaw and was prepared by reaction of 2-chloropyridine N-oxide with sodium hydrosulfide followed by acidification, or more recently with sodium sulfide.
2-chloropyridine N-oxide itself can be prepared from 2-chloropyridine using peracetic acid.
Another approach involves treating the same starting N-oxide with thiourea to afford pyridyl-2-isothiouronium chloride N-oxide which undergoes base hydrolysis to Sodium pyrithione.
2-Bromopyridine can be oxidised to its N-oxide using a suitable peracid (as per 2-chloropyridine), both approaches being analogous to that reported in Organic Syntheses for the oxidation of pyridine to its N-oxide.
A substitution reaction using either sodium dithionite (Na2S2O4) or sodium sulfide with sodium hydroxide will allow the replacement of the bromo substituent with a thiol functional group.
The alternative strategy is to form the mercaptan before introducing the N-oxide moiety.
2-Mercaptopyridine was originally synthesized in 1931 by heating 2-chloropyridine with calcium hydrosulfide, an approach similar that first used to prepare Sodium pyrithione.
The analogous thiourea approach via a uronium salt was reported in 1958 and provides a more convenient route to 2-mercaptopyridine.
Oxidation to the N-oxide can then be undertaken.
The disulfide diSodium pyrithione, 2,2′-dithiobis(pyridine-N-oxide)
Sodium pyrithione is found as a natural product in the Allium stipitatum plant, an Asian species of onion, also known as the Persian shallot.
Sodium Pyrithiones presence was detected using positive ion mass spectrometry using a DART ion source and the disulfide diSodium pyrithione [de] (2,2′-disulfanediylbis(pyridine)-1,1′-dioxide) has been reported from the same species.
DiSodium pyrithione can be prepared in a laboratory by oxidation of Sodium pyrithione with chlorine in the presence of sodium hydroxide:
2 C5H4NOSH + Cl2 + 2 NaOH → ONC5H4-S-S-C5H4NO + 2 NaCl + 2 H2O
DiSodium pyrithione is used as a fungicide and bactericide, and has been reported to possess novel cytotoxic activity by inducing apoptosis.
Properties
Tautomerisation of the sodium salt of Sodium pyrithione
(thione form on the left, thiolate form on the right)
Sodium pyrithione exists as a pair of prototropes, a form of tautomerism whereby the rapid interconversion of constitutional isomers involves the shift of a single proton, in this case between the sulfur and oxygen atoms (shown in the infobox above).
Salts of the conjugate base of Sodium pyrithione can also be considered to exhibit tautomerism by notionally associating the sodium ion with whichever heteroatom bears the negative charge of the anion (as opposed to the formal charges associated with the N-oxide); however, considering the anion alone, this could also be described as an example of resonance.
Sodium pyrithione is a weak acid with pKa values of -1.95 and +4.6 (thiol proton), but is a markedly stronger acid than either of its parent compounds (pyridine-N-oxide and pyridine-2-thiol), both of which have pKa > 8.
Sodium Pyrithione is only slightly soluble in water (2.5 g L-1) but is soluble in many organic solvents (including benzene, chloroform, dichloromethane, dimethylformamide, dimethylsulfoxide, and ethyl acetate) and slight solubility in others (diethyl ether, ethanol, methyl tert-butyl ether, and tetrahydrofuran).
Sodium pyrithione can be used as a source of hydroxyl radical in organic synthesis as it photochemically decomposes to HO• and (pyridin-2-yl)sulfanyl radical.
Applications
Structures of 1:2 complexes of zinc and the conjugate base of Sodium pyrithione
Top: Structural formula of the monomer
Bottom: Ball-and-stick model of the dimer
The conjugate base of Sodium pyrithione (pyrithionate ion) is an anion containing two donor atoms, a sulfur atom and an oxygen atom each bearing a negative formal charge; the nitrogen atom remains formally positively charged.
The thiolate anion can be formed by reaction with sodium carbonate, and zinc Sodium pyrithione is formed when zinc chloride is added.
The anion can act as either a monodentate or bidentate ligand and forms a 1:2 complex with a zinc(II) metal centre.
Zinc Sodium pyrithione has been used since the 1930s though its preparation was not disclosed until a 1955 British patent in which Sodium pyrithione was reacted directly with hydrated zinc sulfate in ethanol.
In its monomeric form, zinc Sodium pyrithione has two of the anions chelated to a zinc centre with a tetrahedral geometry.
In the solid state, Sodium Pyrithione forms a dimer in which each zinc centre adopts a trigonal bipyramidal geometry with two of the anions acting as bridging ligands coordinated through the oxygen atoms in the axial positions.
In solution, the dimers dissociate via scission of zinc-oxygen bonds to each bridging ligand.
Further dissociation of the monomer into its constituents can occur and is undesirable as the complex is more potent in medical applications; for this reason, zinc carbonate can be added to formulations as it inhibits the monomer dissociation.
Zinc Sodium pyrithione has a long history of use in medicated shampoos to treat dandruff and seborrhoeic dermatitis (dandruff can be considered a mild form of seborrheic dermatitis).
Sodium Pyrithione exhibits both antifungal and antimicrobial properties, inhibiting the Malassezia yeasts which promote these scalp conditions.
The mechanisms by which this work are the subject of ongoing study.
Sodium Pyrithione can be used as an antibacterial agent against Staphylococcus and Streptococcus infections for conditions such as athlete’s foot, eczema, psoriasis, and ringworm.
Sodium Pyrithione is known to be cytotoxic against Pityrosporum ovale, especially in combination with ketoconazole, which is the preferred formulation for seborrheic dermatitis.
Sodium pyrithione itself inhibits membrane transport processes in fungi.
Paints used in external environments sometimes include zinc Sodium pyrithione as a preventive against algae and mildew.
Name
Pyrithione sodium (USAN);
Sodium omadine (TN)
Formula
C5H4NOS. Na
Exact mass
148.9911
Mol weight
149.1461
Sodium pyrithione zinc is an antibacterial and antifungal agent developed by scientists in the 1930’s.
Since then Sodium Pyrithione has been used to treat seborrheic dermatitis of the scalp and other skin conditions such as eczema, athlete’s foot, and vitiligo, as well as psoriasis.
Because of its antifungal properties, it is commonly found in dandruff shampoo.
Products containing Sodium pyrithione zinc are available today with and without prescription, and it is the main ingredient in many over-the-counter creams, lotions, soaps, and shampoos.
Sodium Pyrithione also has antibacterial properties and is effective against many pathogens from the Streptococcus and Staphylococcus genera.
Sodium pyrithione zinc`s other medical applications include treatments of psoriasis, eczema, ringworm, fungus, athletes foot, dry skin, atopic dermatitis, tinea, and vitiligo.
Sodium Pyrithiones antifungal effect is thought to derive from its ability to disrupt membrane transport by blocking the proton pump that energizes the transport mechanism.
Stability: At room temperature in the dark, Sodium pyrithione is stable in the pH range 4.5 to 9.5.
At 100°C it is stable for at least 120 hours, at 150°C 29 % of the substance has decomposed within 48 hours.
In the light or in contact with weak oxidizing agents Sodium pyrithione is converted to the disulfide, 2,2-pyridyl-N-oxide disulfide.
With stronger oxidizing agents or in alkaline solution (pH > 9.5) the substance is converted via a number of intermediates to the sulfonic acid; the reaction with reducing agents yields thiopyridine.
Sodium pyrithione zinc, or zinc Sodium pyrithione or zinc pyridinethione, is a coordination complex consisted of Sodium pyrithione ligands chelated to zinc (2+) ions via oxygen and sulfur centers.
In the crystalline state, Sodium Pyrithione exists as a centrosymmetric dimer.
Due to Sodium Pyrithiones dynamic fungistatic and bacteriostatic properties, Sodium pyrithione zinc is used to treat dandruff and seborrheic dermatitis.
Dandruff is a common scalp disease affecting >40% of the world’s adult population, and may be caused by fungi such as Malassezia globosa and M. restricta 3.
Sodium pyrithione zinc is commonly found as an active ingredient in OTC antidandruff topical treatments such as shampoos.
Sodium Pyrithione mediates its action by increasing the cellular levels of copper, and damaging iron-sulfur clusters of proteins essential for fungal metabolism and growth 1.
Due to low solubility, Sodium pyrithione zinc released from the topical formulations is deposited and retained relatively well onto the target skin surfaces 2.
Other uses of Sodium pyrithione zinc include additive in antifouling outdoor paints and algaecide. While its use has been approved in the early 1960’s by the FDA 4, safety and effectiveness of Sodium pyrithione zinc has been reported for decades.
Sodium Pyrithione is not shown to have any significant estrogenic activity according to the in vivo and in vitro assays 4.
Photodegradation in air
This point is regarded not to be relevant because:
– the vapour pressure of NaPT is very low, resulting in negligible exposure to the atmosphere.
– the calculation according to the Atkinson calculation method (5.1.1.001, ESPTF 7031-001) indicates a short half-life (53.8 hours) of sodium Sodium pyrithione in the atmosphere.
Summary of degradation
– Sodium Sodium pyrithione is hydrolytically stable.
– Sodium Sodium pyrithione passes the ready biodegradability test according to OECD 301B and biodegradation is rapid in soil, water-sediment, and STP.
The degradation profile is well identified passing through several transient degradants to a final somewhat persistent degradant 2‑pyridine sulphonic acid (PSA).
– Photolysis is extremely rapid-again leading to the final somewhat persistent degradant 2‑pyridine sulphonic acid (PSA).
– The final degradant, PSA, passes the ready biodegradability test according to OECD 301B.
Special protective equipment for firefighters : In the event of fire, wear self-contained breathing apparatus.
Further information : Standard procedure for chemical fires.
Solubility: Freely soluble in water
Composition: A stable water based dispersion of Sodium Pyrithione (Sodium 2-pyridinethiol-1-oxide)
Density: 1.35 to 1.45 g/cm 3
Appearance: Dark yellow to amber brown solution
Soduim Pyrithione: 40 to 42%
pH: 8.5 to 10.5
Personal precautions : Ensure adequate ventilation.
Avoid contact with the skin and the eyes.
Wear protective gloves/protective clothing/eye protection/face protection.
Take off contaminated clothing and shoes immediately.
Wash contaminated clothing before re-use.
Methods for cleaning up :
Soak up with inert absorbent material.
Sand
Retain and dispose of contaminated wash water.
Pick up and transfer to properly labelled containers.
Keep in suitable, closed containers for disposal.
Advice on safe handling :
Avoid formation of aerosol.
Avoid contact with skin and eyes.
Smoking, eating and drinking should be prohibited in the application area.
Provide sufficient air exchange and/or exhaust in work rooms.
Requirements for storage areas and containers:
Store in original container.
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Use appropriate container to avoid environmental contamination.
Hand protection :
The selected protective gloves have to satisfy the specifications of EU Directive 89/686/EEC and the standard EN 374 derived from it.
The choice of an appropriate glove does not only depend on its material but also on other quality features and is different from one producer to the other.
The break through time depends amongst other things on the material, the thickness and the type of glove and therefore has to be measured for each case.
Gloves must be inspected prior to use.
Replace when worn.
Impervious gloves
Nitrile rubber
Appearance : liquid
Colour : yellow amber
Odour : slight
Flash point : Note: Not applicable
Ignition temperature : Remarks: not determined
Lower explosion limit : Note: Not applicable
Upper explosion limit : Note: Not applicable
Flammability (solid, gas) : Not applicable
Explosive properties : Note: Not applicable
Oxidizing properties : Note: not determined
pH : 8.5 – 10.5 at 40.00 g/l 25 °C
Freezing point/range : -30 – -25.0 °C
Boiling point/boiling range : 109 °C
Vapour pressure : 0.025 hPa
Density : 1.2 – 1.3 g/cm3
Water solubility : 547.0 g/l Note: soluble
Partition coefficient: noctanol/water : Note: Not applicable
Solubility in other solvents : Note: not determined
Viscosity, dynamic : Note: not determined
Relative vapour density : Note: Not applicable
Evaporation rate : Note: not determined
Skin and body protection : Choose body protection in relation to its type, to the concentration and amount of dangerous substances, and to the specific work-place.
Lightweight protective clothing disposable one-piece overall with integral hood
Hygiene measures :
Avoid contact with skin, eyes and clothing.
When using do not eat, drink or smoke.
Eye protection :
Wear protective gloves/ protective clothing/ eye protection/ face protection.
Safety glasses with side-shields
NaPT
Sodi
UT900000
SODIUM OMADINE
thione(reagent)
Sodium pyrithion
SODIUM PYRITHIONE
PYRITHIONE SODIUM
PYRITHIONE SODIUM SALT
Sodium pyrithione(NaPT)
Melting point:-25 °C
Boiling point:109 °C
Density 1.22
refractive index 1.4825
solubility H2O: 0.1 M at 20 °C, clear, faintly yellow
form Solution
color very deep brown
Water Solubility 54.7 g/100 mL
λmax334nm(H2O)(lit.)
Sensitive Hygroscopic
Merck 14,7994
BRN 4026050
InChIKeyWNGMMIYXPIAYOB-UHFFFAOYSA-M
APPEARANCE
clear liquid
ACTIVE MATTER
40.0%
pH VALUE
9 – 11
Sodium Pyrithione is the common name of an organosulfur compound with molecular formula C5H5NOS, chosen as an abbreviation of pyridinethione, and found in the Persian shallot.
Sodium Pyrithione exists as a pair of tautomers, the major form being the thione 1-hydroxy-2(1H)-pyridinethione and the minor form being the thiol 2-mercaptopyridine N-oxide; it crystallises in the thione form.
Sodium Pyrithione is usually prepared from either 2-bromopyridine, 2-chloropyridine, or 2-chloropyridine N-oxide, and is commercially available as both the neutral compound and its sodium salt.
Sodium Pyrithione is used to prepare zinc pyrithione, which is used primarily to treat dandruff and seborrhoeic dermatitis in medicated shampoos, though is also an anti-fouling agent in paints.
All types of aqueous based coolants are susceptible to contamination from bacteria, yeast, and mold.
Regardless of the type of coolant, bacteria are the most frequently detected microbes in used coolant.
Fungi (yeast and mold), while usually present, are not as easily detected by conventional methods, because the filamentous mycelial forms of mold tend to accumulate in machine crevices, in piping, on sump walls, gear boxes and other solid surfaces.
Routine attempts to completely eliminate bacteria through continual use (and sometimes overuse) of bactericides alone usually result in conditions that encourage the growth of yeast and mold.
Heavy fungal contamination can often require both mechanical and chemical treatment.
Dumping, cleaning and recharging fluids are costly procedures.
Moreover, in today’s regulatory climate, disposal of used fluid can be expensive.
Therefore, Sodium Pyrithione is important that the routine treatment of a system includes a fungicide, as well as a bactericide, to ensure longer system life and savings on replacement, cleaning, and disposal costs.
Sodium Pyrithione fungicide is a highly active, broad-spectrum antimicrobial agent that, when used at recommended concentrations, can help to prevent and minimize problems associated with fungal contamination.
Synonyms:
2-Mercaptopyridine-1-oxide sodium salt
Pyrithione sodium salt
1-Hydroxy-2-pyridinethione sodium salt
2-Pyridinethiol-1-oxide sodium salt
Sodium pyrithione
Sodium Omadine
PYRITHIONE SODIUM
Omadine sodium
15922-78-8
Pyrithione sodium [USAN]
AL02725
sodium;1-oxidopyridine-2-thione
Omadine-sodium
Pyrithione sodium (USAN)
Omacide 24
Caswell No. 790A
2(1H)-Pyridinethione, 1-hydroxy-, sodium salt
Sodium 2-sulfidopyridine 1-oxide
Sodium 2-pyridinethiol-1-oxide
2-Mercaptopyridine N-oxide sodium salt
Sodium 1-hydroxypyridine-2-thione
EINECS 240-062-8
EPA Pesticide Chemical Code 088004
SQ 3277
1-Hydroxy-2(1H)-pyridinethionato sodium
2-Mercaptopyridine-N-oxide, sodium salt, 40 w/w % aqueous solution
1-Hydroxy-2(1H)-pyridinethione, sodium salt
Sodium omadine (TN)
Sel de sodium de 1-hydroxy-2 (1H)-pyridinethione [French]
Sodium Pyrithione 40% FPS
Sel de sodium de 1-hydroxy-2 (1H)-pyridinethione
SCHEMBL271923
CHEMBL2105351
DTXSID6034920
SODIUM SALT OF 1-HYDROXY 2(1H)-PYRIDINE THIONE
KKopsanop3380-34-5thione Na
Sodium 2-thioxopyridin-1(2H)-olate
AKOS015891512
1-hydroxypyridine-2-thione sodium salt
FT-0612772
FT-0649466
D05662
1-?hydroxy-?2(1H)?-?Pyridinethione sodium salt
15922-78-8
Pyrithione sodium
1-Hydroxy-2(1H)-pyridinethionato sodium
1-Hydroxy-2(1H)-pyridinethione, sodium salt
AL02725; Omacide 24
Omadine-sodium
SQ 3277
Sel de sodium de 1-hydroxy-2 (1H)-pyridinethione [French]
Sodium 1-hydroxypyridine-2-thione
Sodium 2-pyridinethiol-1-oxide
Sodium Omadine
Sodium pyrithione
2(1H)-Pyridinethione, 1-hydroxy-, sodium
[ChemIDplus] 3811-73-2
2-Pyridinethiol, 1-oxide, sodium salt
Sodium (2-pyridylthio)-N-oxide
Sodium pyrithione
(1-Hydroxy-2-pyridinethione), sodium salt
(1-Hydroxy-2-pyridinethione), sodium salt, tech.
1-Oxo-2-pyridinethiol sodium salt
2-Mercaptopyridine 1-oxide sodium salt
2-Mercaptopyridine oxide sodium salt
2-Mercaptopyridine-N-oxide sodium salt
2-Pyridinethiol N-oxide sodium salt
2-Pyridinethiol-1-oxide sodium salt
Omadine sodium
Sodium (2-pyridylthio)-N-oxide
Sodium 2-mercaptopyridine 1-oxide
Sodium 2-pyridinethiol 1-oxide
Sodium 2-pyridinethiol N-oxide
Sodium 2-pyridinethiolate 1-oxide
Sodium omadine (VAN)
Sodium, (2-pyridinylthio)-, N-oxide
Thione (reagent);