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Propargyl Alcohol (2-Propyn-1-ol) is a colorless to light yellow liquid used as a three-carbon alkyne building block in pharmaceutical, agrochemical and specialty chemical synthesis; the same molecule carries a terminal triple bond and a primary alcohol group. Its CAS number is 107-19-7 and its molecular formula is C₃H₄O. It has a geranium-like odor and is miscible with water in all proportions. Because it is toxic and flammable, it should be handled only by trained personnel and with strict safety measures.
Ethynyl carbinol is an important component of the inhibitor packages that protect steel in acid media and of the secondary brightener additives in nickel plating baths. The pi electrons of the triple bond attach to the metal surface; in concentrated hydrochloric and sulfuric acid they reduce the corrosion rate and hydrogen uptake, and in a nickel bath they refine the grain structure and smooth out roughness. For this reason it is a sought-after additive in oil well acidizing, steel pickling and electroplating.
Hydroxymethylacetylene is a versatile intermediate from which the IPBC mold inhibitor, chlorinated solvent stabilizers and various pharmaceutical and agrochemical actives are prepared. It supplies the propargyl unit in the production chains of products such as sulfadiazine, fosfomycin, clodinafop-propargyl and propargite. Buyers are advised to verify purity, water content and storage conditions from the product documents. This product can be supplied from ATAMAN KİMYA; for technical information and requests, contacting ATAMAN KİMYA is recommended.
WHAT IS PROPARGYL ALCOHOL (2-PROPYN-1-OL)?
Propargyl Alcohol (2-Propyn-1-ol), systematically prop-2-yn-1-ol and written HC≡C–CH₂OH, is the simplest acetylenic primary alcohol. A triple bond sits at one end of the molecule and a hydroxyl group on the carbon next to it. These two reactive centers make the substance a building block open to both alcohol and terminal alkyne chemistry.
At room temperature it is a clear, mobile liquid whose color runs from colorless to light straw yellow. The odor resembles geranium, and the odor threshold is reported as about 0.15 ppm. It is lighter than water (relative density about 0.95–0.97) and mixes with water, ethanol, ether and acetone.
The most common industrial route is the Reppe synthesis, in which acetylene and formaldehyde are combined over a copper catalyst. The main product of this reaction is 2-butyne-1,4-diol; Propargyl Alcohol (2-Propyn-1-ol) forms as a by-product at about 5% and is separated by distillation.
A second, patented method decomposes butynediol at 130–180 °C over a copper acetylide catalyst to give Propargyl Alcohol (2-Propyn-1-ol) and formaldehyde. This route does not need high acetylene pressure; yields of 75–94% and gas chromatography purity above 99% have been reported.
Commercial grades are mostly 98–99.9% pure. BASF reports a minimum of 99.3% and some Chinese producers a minimum of 99.5–99.6%, while laboratory grades show values such as a minimum of 98%. Water content and other limits vary with the grade.
Production is concentrated in a few large companies and mainly in China; the annual capacity of one of the large Chinese producers is reported as about 3,000 tonnes. The global market is estimated at a few tens of millions of dollars per year. Pharmaceuticals, agrochemicals, corrosion inhibitors and plating additives are the main user groups.
It should not be mixed up with substances of similar name. Allyl alcohol (CAS 107-18-6) has a double bond, while propyl alcohol (1-propanol, CAS 71-23-8) is a saturated alcohol. Propargyl bromide, propargyl chloride, propargylamine and propargyl acrylate are separate chemicals derived from Propargyl Alcohol (2-Propyn-1-ol).
Some catalogs list oxyethylated derivatives under similar names. These are separate products with their own CAS numbers, used in nickel plating and in corrosion inhibition. Checking the CAS number as well as the product name when ordering is therefore important.
Because it is a hazardous substance, its use calls for serious precautions. In the harmonized EU classification it appears as a flammable liquid; toxic if swallowed, in contact with skin and if inhaled; causing severe skin burns; and harmful to aquatic life with long-lasting effects. It can polymerize uncontrollably with heat, light, bases and oxidizers.
The risk is real: in 2018 at a chemical plant in France, a drum kept for a long time above 30 °C polymerized, exploded and caused a fire. The incident shows that storage temperature and packaging age are decisive for safety.
COMMON PRODUCT AND CHEMICAL NAMES OF PROPARGYL ALCOHOL (2-PROPYN-1-OL):
Agrisynth PA
Propiolic Alcohol
1-Propyn-3-yl Alcohol
1-Propyn-3-ol
3-Hydroxypropyne
3-Hydroxy-1-propyne
1-Hydroxy-2-propyne
Hydroxymethylacetylene
Acetylenyl Carbinol
Acetylene Carbinol
Ethynylmethanol
Ethynylcarbinol
Ethynyl Carbinol
2-Propynyl Alcohol
Propynyl Alcohol
Propynol
3-Propynol
Prop-2-ynol
2-Propynol
Prop-2-yn-1-ol
2-Propyn-1-ol
Propargylic Alcohol
Propargyl Alcohol
107-19-7
Most of these names express the same substance through different naming systems. Prop-2-yn-1-ol is the systematic name; 2-propyn-1-ol and 3-propynol come from differences in numbering, while ethynyl carbinol and ethynylmethanol come from describing the structure as an ethynyl derivative of methanol.
The word propargyl denotes the –CH₂–C≡CH group derived from the propyne root. Propargyl bromide, propargyl chloride and propargylamine carry the same group but are separate chemicals, not synonyms of Propargyl Alcohol (2-Propyn-1-ol). Some catalogs also spell propynol as “propinol”.
Agrisynth PA is a trade name. Codes such as NA 1986 and UN 1986, which creep into the synonym lists of some catalogs, are old transport numbers rather than substance names; the current UN number is 2929. The 107-19-7 in the list is the CAS number.
Whichever of these names is used in an order, writing the CAS number next to it makes it easier to reach the right product. Purity, water content and packaging details are found in the product documents.
CAS NO, EC / EINECS NO AND CHEMICAL IDENTIFICATION OF PROPARGYL ALCOHOL (2-PROPYN-1-OL)
Product name: Propargyl Alcohol (2-Propyn-1-ol)
Common abbreviation: PA (used especially in the corrosion literature)
Chemical name: Prop-2-yn-1-ol (2-propyn-1-ol)
CAS No: 107-19-7
EC / EINECS No: 203-471-2
EU index number: 603-078-00-X
Molecular formula: C₃H₄O
Molecular weight: 56.06 g/mol
Structural notation: HC≡C–CH₂OH; SMILES: C#CCO
Chemical class: Acetylenic (alkynyl) primary alcohol
Main functions: Acid corrosion inhibitor, brightener and leveling additive for nickel plating, chemical intermediate, stabilizer for chlorinated solvents
The harmonized EU classification, under index number 603-078-00-X, includes the following categories: flammable liquid category 3 (H226), acute toxicity category 3 by the oral, dermal and inhalation routes (H301, H311, H331), skin corrosion category 1B (H314) and long-term aquatic hazard category 2 (H411). Stricter classifications are also seen in some supplier documents.
UN number 2929, class 6.1 and subsidiary hazard class 3 are used in transport. In customs, heading 2905.29, which covers unsaturated acyclic alcohols, applies; the detailed code should be verified for the product and the country.
Databases also hold records such as RTECS number UK5075000, US waste code P102 and NSC 8804. These codes complete the identity but give no information about product quality.
CAS and EC numbers match the product with the correct substance. Technical, laboratory and pharmaceutical synthesis grades carrying the same number are separated by purity, water and impurity limits; the grade and the required documents should be written next to the number in the order.
CHEMICAL STRUCTURE AND MOLECULAR PROPERTIES OF PROPARGYL ALCOHOL (2-PROPYN-1-OL)
The molecular formula is written HC≡C–CH₂–OH. The first two carbons are joined by a triple bond and the third carries the hydroxyl group. The sp-hybridized carbons of the triple bond keep the C≡C–C axis linear; the hydroxymethyl group stands at the end of this rod-like unit.
The triple bond is made of one sigma and two pi bonds. This electron-rich region attaches to metal surfaces, coordinates with metals and enters addition reactions. Because the terminal C–H bond is on an sp carbon, it is clearly more acidic than in alkanes; with strong bases or with ions such as copper and silver it can give acetylides.
The hydroxyl group belongs to a primary alcohol, and the estimated pKa is about 13.6, so the aqueous solution behaves close to neutral. One product document gives pH 7 for a 50 g/L solution and another pH 3 for a 500 g/L solution. The difference arises from concentration; pH should not be treated as a product property unless the solution concentration is stated.
The molecule is small and polar. Because the hydroxyl group forms hydrogen bonds, the substance mixes with water in all proportions; the logarithm of the octanol-water partition coefficient is about –0.38. This value shows that the substance stays in the water phase and has a low tendency to accumulate in living organisms.
It is neutral and covalent in character and has no ionic component. The oxidation states of the carbons differ: the hydroxymethyl carbon is at the alcohol level and the two triple-bonded carbons at the alkyne level. Oxidation can proceed first to propynal (propiolaldehyde) and then to propiolic acid.
The structure is thermodynamically strained. In the presence of heat, light, bases, oxidizers and peroxides the triple bond can polymerize spontaneously; this reaction releases heat and can raise the pressure in a closed container.
The hydroxyl sitting right next to the triple bond makes the propargylic position reactive. The hydroxyl can form esters, ethers and carbamates, or be converted to a propargyl halide with halogenating agents. The triple bond takes part in Sonogashira coupling and in copper-catalyzed azide-alkyne cycloaddition.
The solubility behavior fits the structure: the hydroxyl and the triple bond raise polarity, while the hydrocarbon part is very short. The substance therefore mixes with water, alcohols and ethers, dissolves in chlorinated and aromatic solvents and does not dissolve in aliphatic hydrocarbons.
In biological systems the enzyme cytochrome P450 2E1 oxidizes the substance to propynal. This more reactive aldehyde inhibits aldehyde dehydrogenase and contributes to liver damage; the high toxicity is linked to this metabolic activation.
PHYSICAL AND CHEMICAL PROPERTIES OF PROPARGYL ALCOHOL (2-PROPYN-1-OL)
General technical properties:
Values may differ with the manufacturer, grade and measurement method. The list below offers general information and cannot replace the manufacturer-specific TDS and SDS documents.
Physical appearance: Clear, mobile liquid ranging from colorless to light yellow (straw colored); geranium-like odor
Chemical character: Neutral, polar, acetylenic primary alcohol; terminal alkyne; prone to polymerization with heat, light and bases
Molecular formula: C₃H₄O
Molecular weight: 56.06 g/mol
CAS No: 107-19-7
EC / EINECS No: 203-471-2
Purity (assay): Mostly at least 98–99.9% in commercial grades (gas chromatography). For example, TCI reports at least 98.0%, Thermo Scientific at least 98.5%, Merck at least 99.0%, BASF at least 99.3%, some Chinese producers at least 99.5–99.6% and a pharmaceutical intermediate supplier at least 99.65%. These are product-specific example specifications
Density: Relative density at 20 °C is 0.948–0.950; one producer gives 0.9485. Literature also gives 0.963 g/mL at 25 °C and one safety data sheet a value of 0.97
Refractive index: n20/D about 1.429–1.435; 1.432 is given most often
Melting point: About –48 to –53 °C according to the documents; –58 °C in one manufacturer document
Boiling point: About 112–115 °C; 113–115 °C is given most often
Flash point: About 33 °C in a closed cup; 36–37.5 °C in an open cup and other methods
Autoignition temperature: About 365 °C
Explosive limits: In air the lower limit is 3.4% and the upper limit 70% by volume (three documents); two documents give 1.9–86.2%. The difference depends on the source and the measurement method
Vapor pressure: About 1.54 kPa at 20 °C, that is about 11.6–12 mmHg; some databases give 15.6 mmHg
Vapor density: About 1.93–1.94 relative to air
Viscosity: About 1.68 mPa·s at 20 °C
Solubility in water: Miscible in all proportions; one document gives about 1,000 g/L at 20 °C
Solubility in organic solvents: Mixes or dissolves with ethanol, ether, acetone, chloroform, benzene and ethyl acetate; slightly soluble in carbon tetrachloride and insoluble in aliphatic hydrocarbons
pH (aqueous solution): About 7 in a 50 g/L solution (TCI), 3 in a 500 g/L solution at 20 °C (Merck). It should not be used as a single value without the concentration
Octanol-water partition coefficient: log Pow about –0.38; –0.35 in one database
pKa: About 13.6 (estimated)
Odor threshold: About 0.15 ppm
Moisture / water content: One supplier gives a maximum of 0.1% and a laboratory grade a maximum of 0.5% by Karl Fischer. The limit is defined in the product specification
Formaldehyde: At most 0.1% in one manufacturer specification; formaldehyde is an impurity that comes from the production route
Color: At most 20 Hazen in one manufacturer specification
Stabilizer: One source reports that the commercial product contains a stabilizer; the type and amount are not stated in most documents and should be learned from the supplier
Decomposition: Stable under usual conditions; it can polymerize with heat, light, bases, peroxides and oxidizers. Carbon oxides are released on combustion
Reactivity: It should not be kept together with phosphorus pentoxide, strong acids and bases, oxidizers, amines, isocyanates, acid chlorides and anhydrides; it attacks many plastics
Flammability rating: Given as health 4, flammability 3, instability 3 in the NFPA 704 rating
Short Description of Physical Properties
It is a liquid lighter than water, of low viscosity and quite volatile at room temperature, with a boiling point around 114 °C. Its flash point of about 33 °C means it gives off vapors that can ignite even in cool surroundings.
The vapors are about 1.9 times heavier than air, collect at floor level and can reach a distant ignition source. The explosive limits are wide; depending on the source, the lower limit is given between 1.9 and 3.4% and the upper limit between 70 and 86%.
The recommendation for cold storage (0–10 °C or 2–8 °C) is not related to freezing, because the melting point is very low. The real reason is the sensitivity of the substance to heat and air.
Small deviations are seen between documents: the melting point is given between –48 and –58 °C, the flash point between 33 and 37.5 °C and the relative density between 0.948 and 0.97. The deviations are explained by measurement method, temperature, purity and literature source. The values to rely on are found in the analysis certificate of the product.
Water content is one of the important indicators of quality and is defined in the product specification; manufacturers state their own limits, for example a maximum of 0.1%. The value of this limit is documented by the analysis certificate.
HOW DOES PROPARGYL ALCOHOL (2-PROPYN-1-OL) WORK AT THE MOLECULAR LEVEL?
Propargyl Alcohol (2-Propyn-1-ol) does not act through the same mechanism in every application: adsorption and film formation on a metal surface, direction of crystal growth on the cathode surface, triple bond and hydroxyl chemistry in synthesis, and slowing of the decomposition chain in chlorinated solvents form the basis of the different uses. What they all share is the triple bond of the molecule.
Acid corrosion inhibition
In concentrated acid the steel surface becomes positively charged and acid anions are drawn toward it. Propargyl Alcohol (2-Propyn-1-ol) binds to the surface through the pi electrons of the triple bond and the oxygen of the hydroxyl and slows both anodic and cathodic steps; it is therefore regarded as a mixed-type inhibitor.
A study on iron in sulfuric acid calculated that each adsorbed molecule displaces about three water molecules from the surface. The free energy of adsorption was found to be about –31.2 kJ/mol, and after long immersion a film of saturated hydrocarbon character was seen on the surface.
Protection comes mainly from the molecules on the surface polymerizing over time into a hydrophobic film, which makes it harder for acid to reach the metal. One study found a film thickness of about 11.3 Å and measured about 97% protection at 0.05 wt% in 4 M HCl at 80 °C.
The effect is strong in concentrated acid and may weaken as the acid is diluted. Inhibition efficiencies of 98.3–99.9% have been reported in HCl at 0.05–0.10 vol% on stainless steel.
Ions and auxiliary substances in the medium change the result. Copper and chromium ions strengthen the effect against corrosion and hydrogen uptake. Fe³⁺ clearly weakens the effect, especially at FeCl₃ levels above 2.5%; arsenic ions increase inhibition but also accelerate hydrogen uptake.
Synergists such as iodide increase surface coverage. On chromium-alloyed steel in 0.5 M sulfuric acid the best result was found with 10 mM Propargyl Alcohol (2-Propyn-1-ol) combined with 0.01% potassium iodide, and adsorption followed the Langmuir isotherm.
Brightener and leveler in nickel plating
In nickel plating, secondary (Class II) brighteners are unsaturated organic compounds. Propargyl Alcohol (2-Propyn-1-ol) attaches to the cathode surface through its pi electrons and slows the reduction of nickel ions at protruding points of high current density; recesses fill, the surface levels and the grain refines.
Class II additives increase internal stress and brittleness and are therefore not used alone; sulfur-containing Class I brighteners such as saccharin balance this effect. In one study, triple-bonded additives were tested separately and their brightness and leveling effects compared.
A patent reports that Propargyl Alcohol (2-Propyn-1-ol) alone gave leveling at 0.15 g/L but skipped plating in low-current-density regions, and that ethoxylated derivatives gave better results. A range of 0.01–0.5 g/L is given for the total acetylenic additive.
As a chemical intermediate
The terminal hydrogen enters Sonogashira coupling with aryl or vinyl halides under palladium and copper(I) catalysis. The same alkyne forms a triazole ring in copper-catalyzed azide-alkyne cycloaddition (CuAAC, “click chemistry”). Because it can also be attached through the alcohol group, Propargyl Alcohol (2-Propyn-1-ol) is an easily available building block for these reactions.
The hydroxyl group is converted with butyl isocyanate into propynyl butylcarbamate; this intermediate is iodinated in aqueous medium at low temperature to give IPBC. In agrochemicals such as clodinafop-propargyl and propargite, Propargyl Alcohol (2-Propyn-1-ol) supplies the propargyl (prop-2-ynyl) group of the molecule.
Oxidation gives propynal and propiolic acid, and halogenation gives propargyl bromide and 3-chloropropyne. Databases also list sulfadiazine, isophytol, idoxuridine and fosfomycin among the products prepared from Propargyl Alcohol (2-Propyn-1-ol).
Stabilization in chlorinated solvents
Trichloroethylene decomposes with metal, moisture and heat to form acid. Propargyl Alcohol (2-Propyn-1-ol), added at 0.005–1 wt%, preferably 0.05–0.5%, together with an auxiliary such as pyrrole, slows this decomposition.
In an accelerated test the acidity of the unstabilized solvent rose to 494 ppm, while in a solvent containing 0.1% Propargyl Alcohol (2-Propyn-1-ol), 0.05% pyrrole and a trace of amine it stayed at 93 ppm. When used alone the effect remained limited.
WHICH SECTORS USE PROPARGYL ALCOHOL (2-PROPYN-1-OL)?
Propargyl Alcohol (2-Propyn-1-ol), a specialty chemical small in volume but valuable in function, is used mainly in metal protection, plating and chemical synthesis. Only the fields documented in the sources examined are listed below.
Oil and gas
Concentrated HCl used in well acidizing and stimulation corrodes steel pipes, tubing and drilling equipment. Propargyl Alcohol (2-Propyn-1-ol), a component of the inhibitor packages added to these acids, has also been tested against iron corrosion in carbon dioxide-containing aqueous media.
Metalworking and acid pickling
In steel pickling in HCl or H₂SO₄ it reduces metal loss and hydrogen uptake. Because hydrogen uptake can cause brittleness in steel, Propargyl Alcohol (2-Propyn-1-ol) is also mentioned in limiting hydrogen embrittlement.
Galvanic and electroplating
Propargyl Alcohol (2-Propyn-1-ol) acts as a brightener and leveling additive in nickel baths; sources also state that it is used as a component in electroless plating baths. It is mostly found at low levels inside commercial additive packages.
Pharmaceuticals and biotechnology
As a synthesis intermediate it is used in preparing sulfonamide-type antibacterials (sulfadiazine), fosfomycin and some antiviral precursors. It is not a component of the final drug but a step in the production chain.
Agriculture
The propargyl group in herbicides such as clodinafop-propargyl and acaricides such as propargite comes from Propargyl Alcohol (2-Propyn-1-ol). Propargite is not approved in the EU; its production and use status differs from country to country.
Paints, coatings and wood protection
In paints and coatings it appears not as a direct component but as the raw material of the IPBC mold inhibitor. IPBC is used in dry-film preservatives, wood preservatives and some adhesives.
Chemistry and fine chemicals
It is used in organic synthesis as a three-carbon acetylenic building block. Propargyl halides, esters, ethers, propiolic acid and various alkyne derivatives are obtained from this substance.
Polymers and plastics
It takes part in preparing alkyne-containing monomers, crosslinkers and functional polymers. Giving polymers new functions through click chemistry is one of the current examples in this field.
Solvent and stabilizer
It is added as a stabilizer to chlorinated hydrocarbons, especially trichloroethylene, to prevent decomposition in vapor degreasing. It is also mentioned as a solvent for cellulose acetate. Because trichloroethylene use is restricted in many regions, this application has narrowed.
Electronics, aerospace and other special fields
It is reported as a component in solder flux, an additive in aerospace paint strippers and a reagent in laboratories. A few sources also mention use as a soil fumigant; the US Environmental Protection Agency could not confirm this.
Food, cosmetics, textiles, paper and detergents are not among the typical use areas of this substance.
IS PROPARGYL ALCOHOL (2-PROPYN-1-OL) USED IN COSMETIC, FOOD AND PHARMACEUTICAL APPLICATIONS?
Short answer: Propargyl Alcohol (2-Propyn-1-ol) is not used as an ingredient in cosmetics or food; in pharmaceuticals it is only a synthesis intermediate. The three fields are discussed separately below.
Cosmetics
Propargyl Alcohol (2-Propyn-1-ol) is not a cosmetic ingredient; there is no INCI name defining a cosmetic function. It causes severe skin burns and can be fatal by skin absorption; its use in leave-on or rinse-off products is therefore unacceptable.
A perfumery raw material database flags the substance as “not for fragrance use”. The cosmetic preservative IPBC is synthesized from this substance; however, IPBC is a separate substance, and this chain does not mean that Propargyl Alcohol (2-Propyn-1-ol) can be used in cosmetics.
Food
Propargyl Alcohol (2-Propyn-1-ol) is not a food additive and has no E number; it is not added to food directly. A food and flavor database flags the substance as “not for flavor use”, and it does not appear in the Food Chemicals Codex either.
No record permitting its use in food contact materials has been found. In food facilities, Propargyl Alcohol (2-Propyn-1-ol) is a technical chemical that must be kept separate from food.
Pharmaceuticals
It is not present in medicines as an active or an excipient. Supplier sources present Propargyl Alcohol (2-Propyn-1-ol) as an intermediate in the synthesis of drugs such as sulfonamide-type antibacterials and fosfomycin; this is an early step in the production chain.
The intermediate must not pass into the final product as a residue. The substance has shown mutagenic effects in some tests, and drug manufacturers therefore carry out impurity control according to international harmonization guidelines. High purity and batch consistency matter in this field.
No pharmacopoeial monograph has been found. The quality of the product to be used in drug synthesis is set by the specification between buyer and producer; the pharmaceutical manufacturing rules of the target country should be assessed separately.
INDUSTRIAL APPLICATIONS OF PROPARGYL ALCOHOL (2-PROPYN-1-OL)
The industrial value of Propargyl Alcohol (2-Propyn-1-ol) comes from its triple bond attaching to metal surfaces and from the same bond being a versatile reaction point in synthesis. In most applications the substance is used not alone but together with auxiliary components; each application has its own performance conditions and regulations.
Production of the IPBC mold inhibitor
The aim is to obtain IPBC, which is used in paints, coatings, wood preservatives, adhesives, metalworking fluids and some personal care products. In this chain, Propargyl Alcohol (2-Propyn-1-ol) first reacts with butyl isocyanate; the carbamate formed is then iodinated in aqueous medium at low temperature.
IPBC was patented by Troy Chemical in 1975 and is reported to be registered in the EU in the range of 10–100 tonnes per year. This production is the foremost indirect contribution of the substance to the paint and coatings sector.
The limitation is that isocyanate and iodine chemistry require process safety. Residual alcohol and other impurities are monitored in the final product; raw material quality can affect the purity and color of IPBC.
Pharmaceutical and agrochemical intermediates
The aim is to add a propargyl or alkyne unit to the target molecule. The alcohol group is used in forming esters, ethers and carbamates, and the triple bond in coupling reactions. Supplier sources give sulfadiazine, fosfomycin and various agrochemicals as examples.
In actives such as clodinafop-propargyl and propargite, the propargyl group is directly in the structure. Databases also list isophytol, idoxuridine and propiolic acid among the products prepared from Propargyl Alcohol (2-Propyn-1-ol).
The reason for preference is that it is a small and inexpensive source of alkyne. The limitations are high toxicity and side reactions that increase at low purity; a supplier marketing a pharmaceutical intermediate stresses a minimum of 99.65% purity, while water, formaldehyde and color are limited according to the step concerned.
Polymer modification and click chemistry
The aim is to give polymers, resins and surfaces triple bond functionality and to couple it with azide-containing molecules. Propargyl Alcohol (2-Propyn-1-ol) is the raw material of monomers such as propargyl acrylate, methacrylate and ether.
Copper-catalyzed azide-alkyne cycloaddition gives a highly selective coupling under mild conditions; it is used in surface functionalization, crosslinking and the development of specialty coatings. Control of residual copper and toxic monomers are the limiting issues.
Nickel plating baths
The aim is to obtain a bright and smooth nickel deposit and to cover roughness on the substrate. Propargyl Alcohol (2-Propyn-1-ol) and its ethoxylated derivative are used in very small amounts as secondary brighteners alongside primary brighteners such as saccharin; the effect begins with adsorption on the cathode surface.
One study showed that adding triple-bonded molecules markedly increased brightness. In the patent literature the total acetylenic additive is in the range of 0.01–0.5 g/L; it is stated that used alone it skips plating at low current density, while ethoxylated derivatives give better leveling.
The limitation is that secondary brighteners increase internal stress and brittleness; they are therefore balanced with a sulfur-containing primary brightener. As the bath ages, feathering or dark areas may appear. Alternatives are other acetylenic additives such as 2-butyne-1,4-diol and its ethoxylates.
Steel pickling and hydrogen embrittlement
The aim is to reduce dissolution of sound metal and hydrogen uptake while HCl or H₂SO₄ removes the oxide layer on the steel surface. Because hydrogen uptake can cause brittleness in high-strength steel, Propargyl Alcohol (2-Propyn-1-ol) is used as an inhibitor covering the surface in the acid.
In one study, 98.3–99.9% protection was obtained on 304L stainless steel in HCl at 0.05–0.10 vol%. Copper and chromium ions increased the effect against corrosion and hydrogen uptake, while arsenic ions increased inhibition but accelerated hydrogen uptake.
The limitation is iron ions accumulating in the bath: because Fe³⁺ clearly lowers the effect, the inhibitor level and efficiency should be monitored as the bath ages. Aluminum alloys need a separate assessment.
Oil well acidizing and stimulation
The aim is to limit the attack of the concentrated hydrochloric acid used to raise well productivity on steel pipes, tubing and drilling equipment. Propargyl Alcohol (2-Propyn-1-ol) and its derivatives are added to acid inhibitor packages for this purpose; a patent describes a mixture containing 80–90 wt% of it.
The reason for preference is strong protection at high temperature and in concentrated acid and the formation of a lasting film on the surface. Halogenated derivatives, adducts and oxyethylated derivatives have also been tested in HCl and carbon dioxide-containing media; a patent gives levels of 5–20 ppm in carbon dioxide-containing media.
The limitation is the high toxicity of the substance and its harm to aquatic life. Cinnamaldehyde-based systems and indolizine derivatives have been developed as alternatives that do not use acetylenic alcohol; efficiency may fall in dilute acid.
Stabilization of chlorinated solvents
The aim is to prevent trichloroethylene used in vapor degreasing from decomposing and forming acid under metal, moisture and heat. Propargyl Alcohol (2-Propyn-1-ol) is added at 0.005–1 wt%, mostly together with auxiliaries such as pyrrole and a trace of amine; its effect alone is limited.
The reason for preference is that at low concentration it protects aluminum and steel equipment from acidic decomposition products. The limitation is that trichloroethylene use is restricted in many regions; in some regions alternative solvents and closed systems are preferred.
Other special applications
Solder flux, electroless plating baths and aerospace paint strippers fall into this group. In laboratories, the substance serves as a research reagent and a three-carbon alkyne building block.
The amounts used in these fields are generally small, and product documentation mostly remains within the formulators’ own knowledge. Companies considering use should obtain product-specific information from the supplier and from regulation.
CONSIDERATIONS IN THE USE OF PROPARGYL ALCOHOL (2-PROPYN-1-OL)
Propargyl Alcohol (2-Propyn-1-ol) is a highly hazardous chemical. Because it is toxic, absorbed through the skin, flammable and prone to polymerization, strict precautions are required at every stage; quality, compatibility and regulatory issues should be assessed together.
Main points to note:
• Skin absorption: The liquid is absorbed quickly through the skin and can be fatal; the NIOSH skin notation is “fatal” for systemic effects. Suitable gloves, protective clothing and face protection should be used where contact is possible, and in case of contact, clothing should be removed and the skin washed with plenty of water
• Inhalation: Vapor pressure is high and the odor threshold low. Work should be carried out in a closed system and under local exhaust ventilation; occupational limits range from 0.2 to 2 ppm depending on the country, and most also carry a skin notation
• Polymerization: It can polymerize uncontrollably with heat, light, bases, oxidizers and peroxides. Storage temperature should be kept below 30 °C, opened containers should not be kept for long, and heat sources should be avoided
• Incompatible substances: Keep apart from phosphorus pentoxide, strong acids and bases, oxidizers, amines, isocyanates, acid chlorides and anhydrides. In basic media, unstable metal acetylides can form with copper, silver and mercury salts
• Fire and explosion: The flash point is about 33 °C. The vapors are heavier than air and form an explosive mixture over a wide range. Ignition sources should be removed, grounding and bonding applied, and non-sparking tools and explosion-proof equipment used
• Material compatibility: Stainless steel, glass and phenolic-lined containers are suitable; clean, rust-free steel is also accepted for short-term use. Aluminum, rubber and epoxy coatings should be avoided because the substance attacks many plastics
• Water and impurities: Water content, formaldehyde and color are defined in the product specification. A grade suited to the intended use should be confirmed by the analysis certificate
• Eyes: The undiluted liquid can leave permanent corneal damage. Fully protective goggles and, where needed, a face shield should be worn, and an eye wash station should be ready in the work area
• Environment: It is toxic to fish and water fleas. It should not be released into drains, soil or waterways
• Waste: Considered hazardous waste in many countries; in the US it is on the acute hazardous waste list (P102). Disposal should be carried out by licensed companies
• Training and records: Employees should be trained, exposure monitored and an emergency plan kept ready
• Regulation: Classification, labeling, transport, occupational exposure and KKDİK/REACH obligations should be reviewed according to the target country
This section is meant to give general information. The current safety data sheet and technical data sheet of the product used should be taken as the basis.
STARTING FORMULATION APPROACHES FOR PROPARGYL ALCOHOL (2-PROPYN-1-OL)
The examples below show at a conceptual level how Propargyl Alcohol (2-Propyn-1-ol) can be evaluated in process and formulation development. They are not validated commercial recipes, production instructions or regulation-compliant final formulas.
Because the substance is toxic, flammable, corrosive and prone to polymerization, this section gives no full ingredient tables, mixing order, temperature or time details. Only the low use levels found in published sources, the variables to be evaluated and the criteria are presented.
Every study should be carried out in closed systems, with trained personnel and in authorized laboratories. Ready-made commercial inhibitor, stabilizer and additive packages often give a safer starting point than working with the pure substance. Regulatory, safety and environmental assessment should be made by specialists.
EXAMPLE 1: ACCELERATED STABILITY EVALUATION IN A TRICHLOROETHYLENE STABILIZER PACKAGE
Purpose: To compare the rise in acidity of trichloroethylene used in vapor degreasing across different combinations of auxiliary components containing Propargyl Alcohol (2-Propyn-1-ol), and to measure the effect of the stabilizer package.
Starting approach:
Solvent: the user’s own trichloroethylene grade; kept constant
Propargyl Alcohol (2-Propyn-1-ol): about 0.005–1 wt% in the literature, preferably 0.05–0.5%; screened stepwise
Auxiliary components: pyrrole (about 0.05% in the literature) and a very small amount of amine; tested as a separate variable
Metal surface: aluminum or steel coupon; kept constant as the medium that accelerates decomposition
Temperature, humidity and time: kept constant to reflect the actual conditions of use
Application approach:
• The unstabilized solvent, the solvent containing only Propargyl Alcohol (2-Propyn-1-ol) and the solvent with the full stabilizer package are put through an accelerated decomposition test under the same conditions
• The acidity level (ppm) is measured at set intervals; the literature reports that acidity rising to 494 ppm in the unstabilized solvent stayed at 93 ppm with the full package
• The appearance and weight loss of the metal coupons are compared
• The moisture level of the solvent and the depletion rate of the stabilizer are monitored
• Results are assessed in light of the regulatory status and alternative solvent options
Safety and quality note: Trichloroethylene is also a toxic and regulated solvent; work should be done in a closed system, under ventilation and in line with the relevant regulation. Where possible, a ready-made stabilizer concentrate should be used instead of the pure substance, and waste solvent should be disposed of by licensed companies.
EXAMPLE 2: FUNCTIONALIZING A POLYMER SURFACE BY CLICK CHEMISTRY
Purpose: To give a polymer or resin surface triple bond functionality through an alkyne-containing linker derived from Propargyl Alcohol (2-Propyn-1-ol), and to evaluate the coupling yield of this surface with an azide-containing molecule.
Starting approach:
Alkyne source: Propargyl Alcohol (2-Propyn-1-ol) or derivatives such as propargyl acrylate or propargyl ether; chosen according to the user’s own synthesis route
Surface or polymer: a carrier with groups suitable for attachment such as hydroxyl, carboxyl or epoxy; kept constant
Azide-containing molecule: a dye, biomolecule or functional chain; selected as a separate variable
Catalyst system: a copper(I) source and ligand; determined according to the user’s own process
Solvent and water content: chosen according to the reaction medium; water tolerance tested separately
Temperature and time: kept constant according to the user’s own model
Application approach:
• After the alkyne function is attached to the surface, the level of attachment is confirmed by a spectroscopic method (for example infrared or NMR)
• The click reaction is carried out with the azide-containing molecule; coupling yield and selectivity are compared
• The residual copper level is measured and the cleaning step is evaluated
• The amount of remaining toxic monomer and free alkyne is checked; the stability of the surface is monitored over time
Safety and quality note: Some propargyl monomers are toxic and prone to polymerization, and azides can be unstable. Work should be done only with trained personnel, in a closed system and on a small scale, and copper-containing waste should be disposed of in line with regulation.
EXAMPLE 3: MONITORING INHIBITOR EFFICIENCY IN A STEEL PICKLING BATH AS IT AGES
Purpose: To follow how iron ions accumulating in an acid pickling bath change the protection efficiency of a Propargyl Alcohol (2-Propyn-1-ol)-based inhibitor over time, and to determine when the bath should be renewed.
Starting approach:
Bath: the user’s own HCl or H₂SO₄ pickling solution; kept constant
Inhibitor: about 0.05–0.10 vol% in the literature (stainless steel in HCl); if a commercial package is used, the manufacturer’s recommendation is the basis
Iron source: Fe²⁺ and Fe³⁺ levels are raised stepwise; in the literature the effect drops markedly at FeCl₃ levels above 2.5%
Metal coupon and temperature: kept constant at actual conditions of use
Application approach:
• The corrosion rate is calculated from the weight loss of coupons in the fresh bath and at different iron levels
• If needed, hydrogen uptake is monitored by measuring hydrogen permeation or loss of mechanical properties
• The iron level at which inhibitor efficiency falls is determined and converted into a bath control limit
• The effect of a synergist (for example iodide) is tested separately
Safety and quality note: Work should be done in a fume hood, allowing for hydrogen gas evolution and acid vapor. Spent acid solution should be disposed of as waste in line with regulation, and where possible a ready-made inhibitor solution should be used instead of the pure substance.
SIMILAR PRODUCTS AND ALTERNATIVES FOR PROPARGYL ALCOHOL (2-PROPYN-1-OL)
Looking for an alternative first requires clarifying the purpose of use; the properties sought for an acid inhibitor, a nickel brightener and a synthesis building block are very different. The substances below can partly take over the function of Propargyl Alcohol (2-Propyn-1-ol) or are structurally close to it; none replaces it in every application.
PROPARGYL ALCOHOL (2-PROPYN-1-OL) AND 2-BUTYNE-1,4-DIOL
2-Butyne-1,4-diol is a symmetrical acetylenic diol with two hydroxyl groups. It is a hygroscopic solid at room temperature and is obtained from the reaction of acetylene and formaldehyde by the Reppe method; Propargyl Alcohol (2-Propyn-1-ol) comes out of this production as a by-product at about 5%.
In nickel plating both are secondary brighteners and are found together with their ethoxylated forms in most baths. Because butynediol is a solid, its vapor pressure and inhalation risk are lower; Propargyl Alcohol (2-Propyn-1-ol) is a liquid and is preferred for its leveling effect. In acid inhibition butynediol does not readily take its place.
PROPARGYL ALCOHOL (2-PROPYN-1-OL) AND 2-METHYL-3-BUTYN-2-OL
2-Methyl-3-butyn-2-ol is a tertiary alcohol with a terminal alkyne; its melting point is about 3 °C and its boiling point about 104 °C. A dermal LD50 of about 1,420 mg/kg in rabbits is reported, which points to a much lower toxicity than Propargyl Alcohol (2-Propyn-1-ol).
This substance is used as a plating additive and an acetylene carrier; in organic synthesis it is also known as a source that replaces acetylene in Sonogashira coupling and whose protecting group can be removed afterwards. It cannot replace Propargyl Alcohol (2-Propyn-1-ol) in syntheses that need primary alcohol chemistry.
PROPARGYL ALCOHOL (2-PROPYN-1-OL) AND 3-BUTYN-2-OL
3-Butyn-2-ol is the secondary alcohol counterpart of Propargyl Alcohol (2-Propyn-1-ol) with an added methyl group. Its boiling point is about 110 °C and its flash point about 34 °C; it takes part in vitamin A synthesis and in Sonogashira and Pauson-Khand reactions.
Although structurally close, its toxicity is similar; one source gives an LD50 of about 57 mg/kg, so it offers no gain in safety. The choice depends on the chiral center of the target molecule and on the synthesis plan.
PROPARGYL ALCOHOL (2-PROPYN-1-OL) AND ALLYL ALCOHOL
Allyl alcohol is a small alcohol carrying a double bond in place of the triple bond, and it too is toxic, flammable and irritating. Most of the occupational exposure values set in the past for Propargyl Alcohol (2-Propyn-1-ol) rest on an analogy with allyl alcohol.
It does not give the same performance in acid inhibition and nickel plating; the film that polymerizes on the surface is formed mainly by the triple bond. It should not be seen as a substitute preferred for safety reasons, only as a member of the same chemical family.
PROPARGYL ALCOHOL (2-PROPYN-1-OL) AND ITS ETHOXYLATES
Ethoxylated Propargyl Alcohol (2-Propyn-1-ol) is a derivative in which ethylene oxide is attached to the hydroxyl group. It is reported to give better leveling in nickel plating and not to skip plating at low current density; it has also been tested as an inhibitor at 5–20 ppm in carbon dioxide-containing media.
The derivative is less volatile and often easier to handle. Because it is a separate substance, its CAS number, regulatory status and toxicity data should be verified separately; in commercial additive packages the ethoxylate is mostly supplied as a mixture with other components.
ACID INHIBITOR ALTERNATIVES
Cinnamaldehyde-based systems are among the best-known alternatives that contain no acetylenic alcohol. A patent finds acetylenic alcohols objectionable from an environmental point of view and describes a cinnamaldehyde-based inhibitor for concentrated HCl. Indolizine derivatives have also been tested on N80 steel in 15–20% HCl without Propargyl Alcohol (2-Propyn-1-ol) synergy.
What these alternatives share is an effort to reduce high toxicity and harm to aquatic life. At high temperature and in concentrated acid, however, Propargyl Alcohol (2-Propyn-1-ol) is still the reference component; most commercial packages therefore work by reducing it rather than removing it altogether.
OTHER SOURCES OF PROPARGYLATION IN SYNTHESIS
Propargyl bromide and 3-chloropropyne are reactive halides that attach the propargyl group directly. They are obtained from Propargyl Alcohol (2-Propyn-1-ol), but they are alkylating and irritating; where esterification or carbamate formation through the alcohol group is possible, the alcohol itself is preferred as the direct building block.
Amines and esters offer different attachment strategies. Which one is chosen depends on the type of bond sought, the reaction conditions and product safety; no building block replaces another in all synthesis plans.
QUALITY CONTROL AND PURCHASING CRITERIA FOR PROPARGYL ALCOHOL (2-PROPYN-1-OL)
Quality control for Propargyl Alcohol (2-Propyn-1-ol) covers stability and the impurity profile as well as classic criteria such as purity and water. The binding specification is found in the technical data sheet and analysis certificate of the producer supplying the product. The main criteria are:
• Identity and grade: The product name should be written together with CAS number 107-19-7; the grade, such as technical, synthesis or laboratory, should be stated clearly
• Purity: Determined by gas chromatography. Commercial specifications mostly show at least 98–99.9%; TCI reports at least 98.0%, Thermo Scientific at least 98.5%, Merck at least 99.0%, BASF at least 99.3%, some Chinese producers 99.5–99.6% and a pharmaceutical intermediate supplier at least 99.65%
• Water content: Measured by Karl Fischer. One supplier reports a maximum of 0.1% and a laboratory grade a maximum of 0.5%; the limit is defined in the product specification. Water can be critical in pharmaceutical and organometallic synthesis
• Formaldehyde: An impurity left from the production route; one producer gives a maximum of 0.1%. It should be monitored for both safety and later reactions
• Color: One producer reports a maximum of 20 Hazen. The substance ranges from colorless to light yellow; yellowing can be a sign of aging and polymerization
• Density and refractive index: Relative density at 20 °C is about 0.948–0.950 and n20/D about 1.429–1.435. Useful in identity confirmation and quick acceptance checks
• Stabilizer: The commercial product is known to contain a stabilizer; the type and amount are not stated in most documents. Since it may affect synthesis or plating, the supplier should be asked
• Metal ions and other impurities: Ions such as iron and copper can affect plating, acid inhibition and the tendency to polymerize; a limit should be requested according to the intended use
• Batch information: Production date, batch number, packaging type and net quantity should be asked; analysis should be repeated for batches kept for a long time
• Documents: SDS, TDS, a batch-specific analysis certificate and transport information should be requested. For pharmaceutical and agrochemical synthesis, a quality statement and an impurity control framework are also asked for separately
Typical values and binding specifications should not be confused. Criteria specific to solids, such as particle size and bulk density, do not apply to this liquid. Test methods such as gas chromatography and Karl Fischer should be agreed in advance between buyer and seller.
STORAGE AND TRANSPORT OF PROPARGYL ALCOHOL (2-PROPYN-1-OL)
Propargyl Alcohol (2-Propyn-1-ol) should be kept in its tightly closed original packaging in a cool, dry, well-ventilated place away from ignition sources. Because it is sensitive to heat, light and air, many suppliers recommend storage under inert gas. The store should be suitable for toxic and flammable liquids, lockable and with a leak-proof floor.
The recommended temperature varies by document: TCI states 0–10 °C, CDH, Molekula and Thermo Scientific 2–8 °C; Merck gives a range of 2–30 °C, and another source states below 30 °C. The reason for cold storage is the risk of polymerization, not freezing. What counts is the manufacturer’s own instruction.
An incident report from France describes a polymerization explosion in a drum kept above 30 °C for a long time. Among the lessons of the report are keeping opened drums under nitrogen and using them within a few weeks, and storing unopened ones below 30 °C and for less than about a year.
Suitable packaging materials are clean stainless steel, glass and phenolic-lined containers; aluminum, rubber and epoxy coatings should be avoided, because the substance attacks many plastics. BASF states 0.5 kg, 186 and 190 kg drums and bulk shipment; one producer gives 180 kg drums, and Indian suppliers 35, 50 and 200 kg drums.
Incompatible substances are phosphorus pentoxide, strong acids and bases, oxidizers, amines, isocyanates, acid chlorides and anhydrides. Contact with copper, silver and mercury salts can lead to the formation of explosive metal acetylides. The store should be kept apart from food and feed areas.
In transport, most documents use the wording UN 2929, class 6.1 (subsidiary hazard 3), toxic liquid, flammable, organic, n.o.s. The packing group is I or II depending on the document: TCI, CDH, Sigma-Aldrich and Molekula state group I, Loba, Henan Haiyuan and Thermo Scientific group II. UN 1986 / NA 1986 is also seen on some pages.
These differences can arise from product form, purity and assessment method. For every shipment, the current safety data sheet of the supplier concerned and the ADR, IMDG or IATA rules should be taken as the basis. The Kemler number is 63.
During transport the packaging must be leak-proof, labels complete and the vehicle protected from heat. It should not be left in the sun for long in summer, and refrigerated transport should be considered where possible. In bulk shipment, it should be verified that tanks and lines are clean, dry and of compatible material.
SAFETY INFORMATION ON PROPARGYL ALCOHOL (2-PROPYN-1-OL)
Many supplier documents list Propargyl Alcohol (2-Propyn-1-ol) as a highly hazardous substance: it is toxic, absorbed through the skin, corrosive and flammable, and can polymerize uncontrollably. The information below is for the general reader and does not replace the product-specific safety data sheet.
Main hazards:
• Classification: The harmonized EU classification is flammable liquid category 3 (H226), acute toxicity category 3 by the oral, dermal and inhalation routes (H301, H311, H331), skin corrosion category 1B (H314) and long-term aquatic hazard category 2 (H411). Some suppliers use stricter classifications; for example H300, H310, H330, H341, H372 and, at one supplier, H350 are seen
• Acute toxicity: The oral LD50 in rats is reported as about 20–70 mg/kg depending on the documents and the dermal value in rabbits as about 16–88 mg/kg. The inhalation LC50 in rats is about 873 ppm over two hours. There is a skin notation; absorption of the liquid through the skin can be fatal
• Skin and eyes: The undiluted liquid can cause second-degree burns within minutes and permanent eye damage. It is a lachrymator; the odor threshold is about 0.15 ppm
• Inhalation: The vapors irritate the nose, throat and lungs; liver and kidney effects have been reported with repeated exposure. Occupational limits vary by country: NIOSH and ACGIH 1 ppm (skin), Germany and Switzerland 2 ppm, the Dutch Health Council recommendation 0.2 ppm
• Long-term effects: In the US National Toxicology Program inhalation study in rats and mice the nose was the main target, and some evidence of carcinogenic activity was reported in male rats. The substance has been found mutagenic in some bacterial tests
• Fire and explosion: The flash point is about 33 °C, the vapors are heavier than air and form an explosive mixture over a wide range. In a fire, carbon dioxide, alcohol-resistant foam or dry chemical powder is used; a strong water jet is not recommended. The NFPA 704 rating is health 4, flammability 3, instability 3
• Reactivity: It can polymerize with heat, light, bases, peroxides and oxidizers; ignition on contact with phosphorus pentoxide has been reported. Heating in a closed container can lead to pressure build-up and explosion
• Personal protective equipment: Work should be done in a closed system or fume hood. Gloves approved in the safety data sheet and with permeation data (for example butyl rubber), full face protection or sealed goggles, protective clothing and, when needed, respiratory protection should be worn. An eye wash and an emergency shower should be ready
• Spills: The area should be evacuated, ignition sources shut off and ventilation provided. Spilled material should be collected with an inert absorbent and not released to the drain. Emergency guides recommend an isolation distance of 50 m for small spills and 800 m for a tank fire
• First aid: In case of contact, contaminated clothing should be removed, skin and eyes washed with plenty of water for at least 15 minutes and, if inhaled, the person taken into fresh air. In every case medical help and a poison control center should be called at once; symptoms may be delayed
• Environment: LC50 is reported as about 1.53 mg/L for fish and about 3.36 mg/L for water fleas. It is toxic to aquatic organisms and must not be released to water, soil or drains
• Waste: Listed as acute hazardous waste in the US (P102). It should be disposed of by licensed companies in line with hazardous waste regulation
This section is for general information only; it does not replace the product-specific SDS.
WHAT SHOULD BE CONSIDERED WHEN BUYING PROPARGYL ALCOHOL (2-PROPYN-1-OL)?
The market for Propargyl Alcohol (2-Propyn-1-ol) is reported to be worth about 30–60 million US dollars in 2025 and expected to grow by about 3–5% a year. Production is concentrated in companies such as Henan Haiyuan, Dezhou Tianyu and Shandong Donge Fengle in China, and in BASF. The decision should be assessed in terms of safety and continuity as well as price.
Main points to consider:
• Correct chemical identity: The substance with CAS number 107-19-7 and the name prop-2-yn-1-ol should be requested. Products with similar names, such as the ethoxylate, 2-(prop-2-ynyloxy)ethanol, 3-butyn-2-ol and propargylamine, are separate substances
• Quality suited to the use: The purity, water, formaldehyde and color limits needed for an acid inhibitor, a plating additive and drug synthesis differ; the requirement should be turned into a written specification in advance
• Water limit: The water limit defined in the specification and the measurement method should be asked; this information is given in the analysis certificate
• Product documents: The current SDS, TDS, a batch-specific analysis certificate and transport documents should be requested. The classification and packing group in the SDS should match the shipping documents
• Packaging and logistics: Options range from small laboratory bottles to 190 kg drums and bulk loading. A company authorized for dangerous goods transport, a suitable vehicle and any cold chain need should be planned separately
• Batch consistency and shelf life: The production date should be asked, stock rotation planned and opened containers used up quickly
• Technical support of the supplier: Being able to advise on safe handling, storage and the choice of inhibitor or additive is a great advantage
• Regulation: The substance is subject to toxic and hazardous substances regulation in the target country, to KKDİK and REACH obligations, to dangerous goods transport rules and to occupational exposure limits; the buyer should check the required permits and registrations
• Total cost of supply: Cold storage, dangerous goods freight, protective equipment, waste disposal and safety training costs should be added to the unit price
Before ordering, the safety and specification documents should be reviewed in full, and for critical applications a preliminary trial with a sample should be carried out.
SUPPLY OF PROPARGYL ALCOHOL (2-PROPYN-1-OL) FROM ATAMAN KİMYA
Propargyl Alcohol (2-Propyn-1-ol), used in acid corrosion inhibition, nickel plating, pharmaceutical and agrochemical synthesis and IPBC production, is a specialty chemical carrying a terminal alkyne and a primary alcohol. Because it is toxic and flammable, document and quality verification is especially important when selecting it.
For technical information, quotations and product requests, contacting ATAMAN KİMYA is recommended. Sharing the intended use, the grade wanted and the order conditions in the request allows the right product to be identified quickly.
The current stock status, grade, purity, water and formaldehyde level, stabilizer information, origin, packaging, transport conditions, regulatory compliance and documents of the product should be confirmed with ATAMAN KİMYA before ordering. Writing CAS number 107-19-7 together with the product name in the order prevents confusion.
Communicating to ATAMAN KİMYA in advance the grade sought for acid inhibition, a plating additive or drug synthesis, the water and formaldehyde limits, the packaging type and the required documents allows the suitability of the product and the current supply status to be assessed more reliably.
Sharing the following information in a quotation request makes it easier to evaluate the right product:
• Sector of use and final application, for example acid inhibitor, nickel plating, pharmaceutical or agrochemical synthesis, IPBC production
• Required grade and purity limit
• Required water content, formaldehyde and color limits
• Stabilizer requirement or expectation of a stabilizer-free grade
• Required CAS number (107-19-7) and, if any, brand or product code
• Estimated order quantity and shipment frequency
• Required packaging type and size, storage and unloading facilities
• Requested documents: SDS, TDS, certificate of analysis and transport documents
• If available, the TDS or analysis information of the current product
Because the product is toxic and flammable, the buyer should also check that receiving and storage conditions comply with the dangerous goods regulation of the target country.
For ATAMAN KİMYA contact details, the contact page on the company’s website can be used.
FREQUENTLY ASKED QUESTIONS ABOUT PROPARGYL ALCOHOL (2-PROPYN-1-OL)
What is Propargyl Alcohol (2-Propyn-1-ol)?
It is the simplest acetylenic primary alcohol, with the formula HC≡C–CH₂OH. A colorless to light yellow, mobile liquid with a geranium-like odor, it is used as an intermediate in pharmaceutical, agrochemical and IPBC synthesis, and as an acid inhibitor and nickel plating additive.
What does Propargyl Alcohol (2-Propyn-1-ol) mean?
The name comes from the propargyl (prop-2-ynyl) group, which carries a triple bond. Its systematic name is prop-2-yn-1-ol; it is also called ethynyl carbinol, 2-propyn-1-ol and propynol. Its structure has a triple bond at one end and a hydroxyl group at the other.
What is the CAS number of Propargyl Alcohol (2-Propyn-1-ol)?
The CAS number is 107-19-7. Products with similar names, such as the ethoxylate, propargylamine or 2-(prop-2-ynyloxy)ethanol, have different numbers; the CAS number and the product name should be written together in the order.
What is the EC / EINECS number of Propargyl Alcohol (2-Propyn-1-ol)?
It is 203-471-2. In the harmonized EU classification it appears under index number 603-078-00-X.
What is the chemical formula of Propargyl Alcohol (2-Propyn-1-ol)?
It is C₃H₄O. The molecular weight is about 56.06 g/mol. Its structural notation is HC≡C–CH₂OH or C#CCO.
Is Propargyl Alcohol (2-Propyn-1-ol) used in cosmetics or food?
No. It is not a cosmetic ingredient and has no INCI name; it is not a food additive either and carries no E number. The IPBC used as a preservative in cosmetics is synthesized from this substance, but it is a separate substance.
What is the difference between Propargyl Alcohol (2-Propyn-1-ol) and 2-butyne-1,4-diol?
Propargyl Alcohol (2-Propyn-1-ol) is a volatile liquid with one hydroxyl. 2-Butyne-1,4-diol, by contrast, is a hygroscopic solid with two hydroxyls and is the main product of the production in which Propargyl Alcohol (2-Propyn-1-ol) forms as a by-product. Both are secondary brighteners in nickel plating, but they are not the same substance.
What is Propargyl Alcohol (2-Propyn-1-ol) used for?
It is used to provide an alkyne building block in pharmaceutical and agrochemical synthesis, to make IPBC, to protect steel in acid media, to give brightness and smoothness in nickel plating and to stabilize trichloroethylene.
In which sectors is Propargyl Alcohol (2-Propyn-1-ol) used?
It is used in fine chemicals, pharmaceuticals, agrochemicals, the paint and wood protection chain (IPBC), oil and gas, metalworking and pickling, electroplating and polymer modification. It is not an ingredient in cosmetics or food.
How does Propargyl Alcohol (2-Propyn-1-ol) prevent acid corrosion?
It attaches to the steel surface through the pi electrons of the triple bond and the hydroxyl oxygen and slows anodic and cathodic reactions. The molecules on the surface polymerize over time and give a hydrophobic film that limits access of the acid to the metal.
What is Propargyl Alcohol (2-Propyn-1-ol) good for?
In synthesis it is a versatile building block offering both alcohol and alkyne functions; in concentrated acid it reduces metal loss and hydrogen uptake, and in a nickel bath it gives a bright and smooth deposit.
How does Propargyl Alcohol (2-Propyn-1-ol) work in nickel plating?
As a secondary brightener it adsorbs on the cathode surface and slows the reduction of nickel ions at protruding points; recesses fill, the surface levels and the grain structure refines. Its effect is balanced with primary brighteners such as saccharin.
Is Propargyl Alcohol (2-Propyn-1-ol) soluble in water?
Yes. It mixes with water in all proportions; it also mixes or dissolves with ethanol, ether, acetone, chloroform and benzene. It does not dissolve in aliphatic hydrocarbons.
How much Propargyl Alcohol (2-Propyn-1-ol) is used in acid inhibition?
The literature reports levels of about 0.05–0.10 vol% in HCl for stainless steel; in well acidizing, an inhibitor mixture based on this substance has been added at about 0.5–20% of the acid fluid. The actual dose depends on temperature, acid type and the commercial package.
Is Propargyl Alcohol (2-Propyn-1-ol) a hazardous substance?
Yes, it is highly hazardous: toxic if swallowed, in contact with skin and if inhaled, it causes severe skin burns and eye damage, is flammable and is harmful to aquatic life. A closed system, suitable protective equipment and the product-specific SDS are essential.
Why can Propargyl Alcohol (2-Propyn-1-ol) be fatal through absorption via the skin?
Because it is a small, polar, water-miscible molecule, it passes quickly through the skin. A dermal LD50 of about 16–88 mg/kg in rabbits is reported and there is a skin notation. In case of contact, contaminated clothing should be removed, the skin washed with plenty of water and medical help sought at once.
Is Propargyl Alcohol (2-Propyn-1-ol) registered under REACH?
It has a harmonized classification in the EU and notifications in the ECHA classification and labelling inventory. The registration number, tonnage band and use scope should be confirmed from the ECHA database and the supplier; the situation under KKDİK in Türkiye should be checked separately.
What is the physical appearance of Propargyl Alcohol (2-Propyn-1-ol)?
It is a colorless to light yellow, clear, mobile liquid with a geranium-like odor. The flash point is about 33 °C, the boiling point about 114 °C and the relative density about 0.95.
What is the UN number of Propargyl Alcohol (2-Propyn-1-ol)?
Most documents state UN 2929, class 6.1 (subsidiary hazard 3). The packing group is I or II depending on the document; UN 1986 / NA 1986 also appears on some pages. The current SDS and transport regulation should be checked for every shipment.
Why are water and formaldehyde important in Propargyl Alcohol (2-Propyn-1-ol)?
In syntheses involving water, isocyanate and metal catalysts it can affect the reaction. Formaldehyde is an impurity from the production route and matters for both safety and later reactions; limits vary by supplier, for example a maximum of 0.1%.
What does the price of Propargyl Alcohol (2-Propyn-1-ol) depend on?
It varies with purity, water and formaldehyde limits, packaging, order quantity and the requirements of cold storage and dangerous goods transport. The costs of the raw materials acetylene and formaldehyde and the concentration of producers also have an effect.
Is there an alternative to Propargyl Alcohol (2-Propyn-1-ol)?
It depends on the use. In nickel plating, 2-butyne-1,4-diol and ethoxylates; in acid inhibition, cinnamaldehyde-based systems and indolizine derivatives; in synthesis, alkynes such as 2-methyl-3-butyn-2-ol can be evaluated; none replaces it in every application.
How should Propargyl Alcohol (2-Propyn-1-ol) be stored?
It should be stored in a closed original package in a cool, dry, ventilated place away from ignition sources. Many suppliers recommend storage under inert gas at 2–8 °C or at most 30 °C; opened containers should not be kept for long.
Which documents should be requested when buying Propargyl Alcohol (2-Propyn-1-ol)?
The basic documents are the SDS, TDS and a batch-specific analysis certificate. Depending on the application, a quality statement, a transport document and regulatory information may also be requested.
Which technical properties are important when buying Propargyl Alcohol (2-Propyn-1-ol)?
Purity, water content, formaldehyde, color, relative density, refractive index, stabilizer information and the impurity profile are the basic criteria. Packaging, production date and batch consistency should also be asked.
PROPARGYL ALCOHOL (2-PROPYN-1-OL) – TECHNICAL SUMMARY
Chemical name: Prop-2-yn-1-ol; Propargyl Alcohol (2-Propyn-1-ol)
Common name: Propargyl Alcohol (2-Propyn-1-ol), 2-Propyn-1-ol, Ethynyl carbinol, Propynol, Hydroxymethylacetylene
CAS No: 107-19-7
EC / EINECS No: 203-471-2
Molecular formula: C₃H₄O
Molecular weight: 56.06 g/mol
Chemical class: Acetylenic primary alcohol; terminal alkyne
Physical appearance: Colorless to light yellow, clear, mobile liquid; geranium-like odor
Main properties: Relative density about 0.948–0.950 (20 °C), refractive index about 1.429–1.435, boiling point about 112–115 °C, melting point about –48 to –58 °C, flash point about 33 °C (closed cup), vapor pressure about 1.54 kPa (20 °C), miscible with water in all proportions
Main functions: Synthesis intermediate, acid corrosion inhibitor, nickel plating secondary brightener, chlorinated solvent stabilizer
Key application areas: Pharmaceutical and agrochemical synthesis, IPBC production, oil well acidizing and steel pickling, electrolytic nickel plating, trichloroethylene stabilization, click chemistry and polymer modification
Parameters critical for quality control: Purity, water content, formaldehyde, color, relative density, refractive index, stabilizer, metal ions
Storage: In a cool, dry, ventilated place, in a closed original container; mostly cold and under inert gas; away from heat, light, bases, oxidizers and incompatible substances
Regulation: Under the harmonized EU classification flammable liquid category 3 (H226), acute toxicity category 3 (H301, H311, H331), skin corrosion category 1B (H314) and aquatic chronic category 2 (H411); for transport UN 2929, class 6.1 (3), packing group I or II depending on the document; not used as an ingredient in cosmetics and food; REACH and KKDİK status and permits of use should be confirmed with the supplier and current regulation.
