Quick Search
Perfluorooctanoic acid is a fully fluorinated eight-carbon carboxylic acid belonging to the perfluoroalkyl substance family.
Perfluorooctanoic acid combines a hydrophilic carboxylic acid group with a hydrophobic and lipophobic perfluorinated carbon chain.
Perfluorooctanoic acid historically functioned as a fluorosurfactant, polymerization aid, surface-treatment intermediate, and precursor for fluorinated chemicals.
Perfluorooctanoic acid is now subject to extensive production, use, marketing, emission, waste, and procurement restrictions because of exceptional environmental persistence and serious health concerns.
CHEMICAL IDENTITY AND COMMON NAMES
Perfluorooctanoic acid is the linear free-acid form represented by C7F15COOH.
Perfluorooctanoic acid dissociates in water to form the perfluorooctanoate anion.
Commercial and environmental references to PFOA can encompass the linear acid, branched isomers, salts, and compounds capable of degrading to Perfluorooctanoic acid.
These forms require separate analytical identification because their molecular forms, solubilities, and regulatory treatment are not identical.
Chemical Name: Perfluorooctanoic acid
IUPAC Name: 2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-Pentadecafluorooctanoic acid
CAS Index Name: Octanoic acid, pentadecafluoro-
Chemical Family: Perfluoroalkyl carboxylic acid
Substance Group: Per- and polyfluoroalkyl substances
Dissociated Form: Perfluorooctanoate
Synonyms and Common Names: Perfluorooctanoic acid, PFOA, n-PFOA, Linear PFOA, L-PFOA, PFOA free acid, C8, C8 acid, C8-PFCA, PFCA-C8, C8 perfluorocarboxylic acid, Pentadecafluorooctanoic acid, Pentadecafluoro-n-octanoic acid, Pentadecafluorocaprylic acid, Pentadecafluoro-n-caprylic acid, Perfluorocaprylic acid, Perfluoro-n-caprylic acid, Perfluoro-n-octanoic acid, n-Perfluorooctanoic acid, F-n-octanoic acid, Perfluoroheptanecarboxylic acid, Octanoic acid, pentadecafluoro-, Octanoic acid, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluoro-, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-Pentadecafluorooctanoic acid, C7F15COOH
TECHNICAL IDENTIFICATION
CAS Number: 335-67-1
EC Number: 206-397-9
Index Number: 607-704-00-2
Molecular Formula: C8HF15O2
Molecular Weight: 414.07 g/mol
UNII: 947VD76D3L
RTECS Number: RH0781000
PubChem CID: 9554
InChIKey: SNGREZUHAYWORS-UHFFFAOYSA-N
Canonical SMILES: C(=O)(C(C(C(C(C(C(C(F)(F)F)(F)F)(F)F)(F)F)(F)F)(F)F)(F)F)O
UN Number: UN 3261
PHYSICAL AND CHEMICAL PROPERTIES
Appearance: White crystalline powder or waxy white solid
Odour: Pungent
Physical State: Solid near normal room temperature
Melting Point: Approximately 52–54 °C for high-purity linear material
Boiling Point: Approximately 189–192 °C
Density: Approximately 1.79–1.80 g/cm³ at 20 °C
Water Solubility: Approximately 9.5 g/L at 20–25 °C
Ammonium Salt Water Solubility: Greater than 500 g/L at 20 °C
Vapour Pressure: Approximately 2.3 Pa at 20 °C
Acid-Base Behaviour: Dissociates strongly in water
Environmental Ionic Form: Predominantly perfluorooctanoate
Flammability: Not combustible
Thermal Decomposition: Decomposes above approximately 300 °C
Hydrolytic Stability: Essentially stable under environmentally relevant conditions
Biodegradability: Not readily biodegradable
Surface Activity: Strong fluorosurfactant behaviour
Octanol-Water Partitioning: Conventional equilibrium log Kow determination is unsuitable because of ionization, surface activity, and micelle formation
Perfluorooctanoic acid has a hydrophilic acid head and a perfluorinated tail that repels both water-associated nonpolar materials and oils.
This amphiphilic structure produces strong adsorption at interfaces and reduces surface and interfacial tension.
Perfluorooctanoic acid remains highly stable against hydrolysis, photolysis, biological degradation, and normal environmental transformation.
Perfluorooctanoic acid therefore persists in water, soil, sediment, wildlife, and humans and can undergo long-range environmental transport.
FUNCTIONAL CHARACTERISTICS
Perfluorooctanoic acid provides fluorosurfactant performance through a carboxylate head group and a low-surface-energy fluorocarbon chain.
Perfluorooctanoic acid historically stabilized aqueous dispersions of fluoropolymer particles during emulsion polymerization.
Perfluorooctanoic acid supports efficient particle nucleation, dispersion control, heat transfer, and reactor operation in fluoropolymer processes.
Perfluorooctanoic acid also functions as a precursor for salts, esters, and other fluorinated intermediates.
Perfluorooctanoic acid does not bioaccumulate primarily through conventional lipid partitioning.
Perfluorooctanoic acid binds strongly to proteins and concentrates particularly in blood, liver, and kidneys.
Perfluorooctanoic acid exhibits extreme persistence because carbon-fluorine bonds resist ordinary chemical, thermal, and biological degradation.
This persistence has displaced technical performance as the controlling consideration in commercial and regulatory decisions.
PRODUCTION AND COMMERCIAL FORMS
Electrochemical fluorination historically converted an eight-carbon acyl precursor in anhydrous hydrogen fluoride into perfluorooctanoyl fluoride.
Hydrolysis of the resulting acid fluoride produced Perfluorooctanoic acid as a mixture of linear and branched isomers.
Historical electrochemical-fluorination material typically contained approximately 78 percent linear Perfluorooctanoic acid and 22 percent branched isomers.
The branched portion included terminally and internally branched structures requiring chromatographic resolution during detailed analysis.
Telomerization provides a second production route based on controlled chain growth of tetrafluoroethylene with a perfluoroalkyl telogen.
Conversion of the resulting linear C8 fluorinated intermediate produces predominantly linear Perfluorooctanoic acid or its derivatives.
Production control addresses acid content, linear and branched isomer distribution, shorter-chain and longer-chain homologues, residual hydrogen fluoride, inorganic fluoride, water, metals, reactive intermediates, and process-derived fluorinated impurities.
Closed equipment, corrosion-resistant construction, effective ventilation, fluoride monitoring, and contained waste treatment are essential.
Commercial forms have included neat free acid, aqueous material, ammonium perfluorooctanoate, sodium perfluorooctanoate, potassium perfluorooctanoate, reagent-grade solid, analytical reference standard, and calibrated analytical solution.
Perfluorooctanoate salts are distinct substances and must not be treated as direct physical-property equivalents of the free acid.
APPLICATIONS AND INDUSTRIES
Fluoropolymer and Fluoroelastomer Processing
Perfluorooctanoic acid historically served as a precursor to processing aids used in aqueous emulsion polymerization of fluoropolymers and fluoroelastomers.
Perfluorooctanoic acid supported dispersion stability, particle-size control, reactor productivity, and production of high-molecular-weight fluorinated polymers.
Surface Treatment
Perfluorooctanoic acid historically contributed to fluorinated systems developed for water, oil, grease, soil, and stain resistance.
Perfluorooctanoic acid and related precursors entered textile, leather, carpet, paper, packaging, coating, paint, polish, and wax applications.
Firefighting Products
Perfluorooctanoic acid occurred in certain fluorinated firefighting foams as an intentional component, processing residue, impurity, or degradation product of precursor substances.
Perfluorooctanoic acid use in firefighting products is now eliminated or restricted under extensive international and national controls.
Electronics and Semiconductor Processing
Perfluorooctanoic acid and related fluorinated surfactants historically supported selected photolithography, etching, cleaning, and specialty electronic processes.
Perfluorooctanoic acid use in these fields is limited to narrowly defined regulatory conditions or has been replaced by alternative technologies.
Specialty Membranes and Technical Textiles
Perfluorooctanoic acid-related materials historically contributed to selected medical textiles, filtration membranes, protective fabrics, and chemically resistant technical products.
Perfluorooctanoic acid use in these applications is governed by narrowly defined exemptions, trace limits, and product-specific controls.
Analytical and Environmental Laboratories
Perfluorooctanoic acid functions as an analytical reference material for drinking water, wastewater, groundwater, soil, sediment, food, biological, product, and waste analysis.
Perfluorooctanoic acid also supports toxicological research, environmental-fate studies, method validation, instrument calibration, remediation assessment, and regulatory monitoring.
Water-Treatment and Remediation Research
Perfluorooctanoic acid serves as a controlled challenge compound for evaluating activated carbon, anion-exchange resin, nanofiltration, reverse osmosis, electrochemical treatment, plasma processes, and other PFAS-control technologies.
Perfluorooctanoic acid removal transfers contamination into spent media or concentrated residual streams unless the subsequent process achieves demonstrated destruction and mineralization.
GRADE SELECTION AND PRODUCT SUITABILITY
Technical or Reagent Grade
Technical selection focuses on acid assay, water, inorganic fluoride, residual hydrogen fluoride, metal content, homologous perfluorocarboxylic acids, and isomer distribution.
Reagent-grade material commonly provides at least 95 percent assay for controlled laboratory synthesis and research.
High-Purity Linear Grade
High-purity linear Perfluorooctanoic acid supports studies requiring separation from branched PFOA isomers.
The specification should state linear-isomer content, individual branched-isomer profile, total PFOA content, and relevant homologues.
Analytical Reference Grade
Analytical reference material requires certified identity, purity, concentration, uncertainty, traceability, homogeneity, and stability information.
A solution standard also requires a defined solvent, concentration, preparation basis, container type, and expiration or retest date.
Isomer-Mixture Grade
Environmental and historical-process analysis frequently requires a standard containing both linear and branched Perfluorooctanoic acid.
The isomer profile must match the intended chromatographic method and reporting convention.
Salt Forms
Ammonium, sodium, and potassium perfluorooctanoates provide different molecular weights, solubilities, physical forms, and analytical conversion factors.
Procurement must distinguish free-acid purity from perfluorooctanoate content and acid-equivalent content.
FORMULATION AND PROCESS CONSIDERATIONS
Perfluorooctanoic acid ionizes in water and produces strongly surface-active solutions.
Solution preparation requires controlled pH, compatible construction materials, contained ventilation, and prevention of aerosol generation.
Perfluorooctanoic acid can attack incompatible metals and reacts with bases, oxidizing agents, and reducing agents.
Contact with reactive metals or incompatible process materials can generate corrosive conditions and hydrogen.
Perfluorooctanoic acid readily contaminates sampling equipment, tubing, seals, laboratory clothing, dust, and work surfaces.
PFAS analytical workflows therefore avoid fluoropolymer tubing, fluoropolymer-lined closures, fluorinated sample-contact components, and materials containing uncontrolled fluorochemical treatments.
Polypropylene and high-density polyethylene are commonly selected for aqueous sampling and working solutions.
Analytical preparation requires dedicated equipment, procedural blanks, matrix blanks, field blanks, and controlled cleaning materials.
Granular activated carbon, anion-exchange media, and high-pressure membranes can separate Perfluorooctanoic acid from water.
Spent adsorbent, regeneration liquid, membrane concentrate, and treatment sludge remain controlled PFAS waste streams.
QUALITY, SPECIFICATIONS AND DOCUMENTATION
Perfluorooctanoic acid identity is established through liquid chromatography-mass spectrometry, nuclear magnetic resonance spectroscopy, infrared spectroscopy, accurate mass, and comparison with characterized reference material.
Quantitative analysis commonly uses liquid chromatography-tandem mass spectrometry with isotope-dilution calibration.
Routine quality testing includes appearance, identity, acid assay, water, inorganic fluoride, residual acidity, metals, linear-isomer content, branched-isomer distribution, shorter-chain homologues, longer-chain homologues, and nonvolatile residue.
Analytical solutions additionally require concentration, solvent composition, preparation uncertainty, homogeneity, stability, and container-compatibility controls.
Procurement documentation normally includes a product specification, certificate of analysis, safety data sheet, batch number, manufacturing or preparation date, retest or expiration date, packaging description, transport classification, and intended-use declaration.
Regulated procurement also requires destination-country authorization, exemption status, import documentation, end-user information, quantity justification, and waste-management arrangements.
SAFETY AND REGULATORY CONSIDERATIONS
Signal Word: Danger
Acute Oral Toxicity: Harmful if swallowed
Acute Inhalation Toxicity: Harmful or toxic if inhaled
Eye Hazard: Causes serious eye damage
Carcinogenicity: Carcinogenic to humans under the current international cancer evaluation
Reproductive Toxicity: May damage the unborn child
Lactation Hazard: May cause harm to breast-fed children
Repeated-Exposure Hazard: Causes damage to the liver through prolonged or repeated exposure
Environmental Hazard: Extremely persistent, mobile, bioaccumulative in humans and selected species, and capable of long-range transport
Perfluorooctanoic acid exposure occurs through inhalation of dust or aerosol, ingestion, and skin contact.
Short-term exposure can cause coughing, sore throat, skin redness, pain, serious eye injury, abdominal pain, nausea, vomiting, and diarrhea.
Long-term exposure is associated with liver effects, immune-system effects, altered serum lipids, developmental effects, reproductive toxicity, and increased cancer concern.
Perfluorooctanoic acid has a human biological elimination half-life measured in years, supporting accumulation during repeated exposure.
Perfluorooctanoic acid, its salts, branched isomers, and PFOA-related compounds are listed for global elimination under Annex A of the international persistent-organic-pollutant controls.
Production and use are limited to applicable registered exemptions and narrowly controlled purposes.
European controls generally establish an unintentional trace limit of 0.025 mg/kg for Perfluorooctanoic acid and its salts and 1 mg/kg for PFOA-related compounds, subject to defined entries and exemptions.
Türkiye controls listed persistent organic pollutants through prohibitions, restrictions, trace limits, authorization requirements, and regulated waste management.
The United States currently applies an enforceable federal drinking-water limit of 4.0 ng/L for Perfluorooctanoic acid and a health-based goal of zero.
The existing compliance deadline is April 2029, while a 2026 proposal would allow eligible systems to request an extension to April 2031.
FIRST AID
Inhalation
Move the exposed person to fresh air and keep the person at rest.
Provide respiratory assistance when breathing is impaired.
Obtain immediate medical attention.
Skin Contact
Remove contaminated clothing and footwear.
Rinse the skin and wash thoroughly with soap and water.
Obtain medical attention for persistent irritation or significant exposure.
Eye Contact
Rinse cautiously with clean water for at least 15 minutes.
Remove contact lenses when present and easy to remove.
Continue rinsing and obtain immediate medical attention.
Ingestion
Rinse the mouth thoroughly.
Do not induce vomiting.
Give water only when the person is conscious and able to swallow.
Obtain immediate medical attention.
Note to Physicians
No specific antidote is established for Perfluorooctanoic acid exposure.
Treatment is supportive and directed toward respiratory irritation, corrosive injury, gastrointestinal effects, and systemic exposure.
Clinical assessment should consider liver function, renal function, exposure duration, and pregnancy or lactation status.
HANDLING AND STORAGE
Handling
Handle Perfluorooctanoic acid in a closed system or controlled laboratory enclosure.
Avoid all unnecessary contact and prevent dust, aerosol, vapour, and contaminated-surface exposure.
Wear chemical-resistant gloves, protective clothing, safety goggles, and face protection.
Use suitable respiratory protection when engineering controls cannot maintain safe airborne conditions.
Ventilation
Provide effective local exhaust ventilation at weighing, charging, transferring, sampling, and spill-control points.
Discharge air must not release uncontrolled Perfluorooctanoic acid into the workplace or environment.
Storage
Keep Perfluorooctanoic acid in its original, tightly closed, correctly labelled container.
Store Perfluorooctanoic acid in a cool, dry, secure, and well-ventilated restricted-access area.
Separate Perfluorooctanoic acid from food, feed, medicines, bases, oxidizing agents, reducing agents, reactive metals, and incompatible materials.
Spill Control
Prevent Perfluorooctanoic acid from entering drains, soil, surface water, groundwater, or ordinary waste.
Collect solid material carefully into a sealed compatible nonmetallic container without generating dust.
Manage contaminated absorbents, protective equipment, wash water, and residues as controlled PFAS waste.
PACKAGING AND PROCUREMENT CONSIDERATIONS
Solid Perfluorooctanoic acid is packaged in tightly sealed, corrosion-resistant containers with compatible inner closures.
Analytical standards are supplied in sealed compatible bottles or ampoules selected for the solvent, concentration, and analytical method.
Aqueous sampling and working solutions commonly use polypropylene or high-density polyethylene containers.
UN Number: UN 3261
Proper Shipping Name: Corrosive solid, acidic, organic, n.o.s.
Transport Hazard Class: 8
Packing Group: III
Food and Feed Separation: Required
Solvent-based analytical standards receive additional transport classification from the solvent composition, flash point, concentration, and package quantity.
Packaging must prevent leakage, moisture entry, breakage, environmental release, and cross-contamination.
Procurement should define the authorized purpose, destination country, required permit, free-acid or salt form, purity, isomer profile, analytical concentration, solvent, package size, documentation, and waste route.
Commercial supply is appropriate only for legally permitted scientific research, analytical reference, regulatory monitoring, or specifically exempted use.
For Perfluorooctanoic acid product information, specifications, documentation, packaging options, and controlled procurement support, contact Ataman Kimya at +90 216 577 10 10 or info@atamankimya.com.
