N-Valeric Acid (Pentanoic Acid) — CAS 109-52-4, ≥99%

n-Valeric Acid (Pentanoic Acid) - CAS 109-52-4

Assay ≥99% GC · Water ≤1000 mg/kg · Pt-Co ≤15 · Heavy metals ≤5 mg/kg as Pb · 50,000 t/a designed capacity

🌱 Before you write a sustainability claim: this material is petroleum-derived.

Valeric acid appears in a lot of bio-based marketing, and there is a real reason for that - the molecule can be produced from lignocellulosic biomass, typically by hydrogenating levulinic acid, and valerate esters have been studied as bio-derived fuel blending components and plasticisers. That literature is genuine.

It does not describe this product. Our n-valeric acid is made by butene hydroformylation from a refinery stream. The molecule is chemically identical to the biomass-route material and performs identically - but the carbon in it is fossil carbon.

The practical consequence: radiocarbon testing under ASTM D6866 or EN 16640 will return essentially zero bio-based content. Any bio-based content claim, BioPreferred label, or ISCC PLUS / REDcert² mass-balance certification made on the strength of this material will fail verification. If your customer requires a certified bio-attributed or biomass-derived grade, tell us at enquiry stage - we will tell you plainly that this is not it, rather than let you build a claim you cannot defend.

🚢 A shipping detail that causes real delays. Because valeric acid has no dedicated UN number, it moves under an n.o.s. entry - and n.o.s. entries require the technical name to appear in brackets after the proper shipping name on the declaration, for example "UN 3265, Corrosive liquid, acidic, organic, n.o.s. (valeric acid), 8, III". Forwarders who are used to substances with their own UN number routinely omit the bracket, and the container gets held at the port. Check the declaration before it goes.

⚠️ "Heavy metals as Pb" is the wrong parameter if you are making refrigeration lubricant.

GB/T 5009.74 is a food-additive method - a colorimetric sulfide test that reports a single lumped figure expressed as lead. It is a sensible control for flavour and food-chain use, and its presence on the certificate signals that this material is made with that market in mind.

It tells you almost nothing about the metals that matter inside a sealed compressor. Sodium, iron and copper catalyse ester hydrolysis and drive total acid number upward in service - and none of them are what a heavy-metals-as-Pb test is looking for. If this acid is going into a polyol ester base oil, ask us for the individual Na / Fe / Cu / Ca / Zn suite by GB/T 17476-2023 instead. We report it on request and it is the number your POE customer will eventually ask you for anyway.

01Crude oil - own import quota, tank farm, pipelines and transport fleet

02Refining - crude processed to yield the butene stream

03Hydroformylation - butene plus syngas to valeraldehyde

04Rectification - n-valeraldehyde separated from the branched isomer

05Oxidation - aldehyde oxidised to n-valeric acid

❄️ 1. Polyol Ester Base Oils - the largest technical outlet

Esterified with pentaerythritol, trimethylolpropane or dipentaerythritol, n-valeric acid builds the polyol ester (POE) base stocks used in HFC and HFO refrigeration lubricants, aviation turbine oils and biodegradable hydraulic fluids. Pentaerythritol tetravalerate alone consumes roughly 864 kg of valeric acid per tonne of ester at theoretical conversion.

What the linear C5 chain contributes, and what it costs you. A straight C5 chain gives low viscosity, excellent low-temperature fluidity and high miscibility with HFC and HFO refrigerants - R-134a, R-410A, R-32, R-1234yf. That miscibility is the whole reason POE displaced mineral oil in these systems, since a lubricant that separates from the refrigerant will not return from the evaporator.

The trade-off is hydrolytic stability. The alpha carbon of a linear acid is an unhindered methylene, so linear-acid esters hydrolyse more readily than esters of branched acids where the alpha carbon is secondary or quaternary. This is exactly why commercial POE base stocks are almost always mixed-acid esters, not single-acid ones: linear C5 for viscosity and miscibility, branched C8 or C9 for hydrolytic and oxidative resistance. Shifting the C5-to-C9 ratio is how formulators move between ISO VG grades.

🔗 The branched partner acid, with its own low-metal specification: Isononanoic Acid (INA) · POE Esters in Refrigeration Compressors

🧪 2. Valeryl Chloride & Pharmaceutical Intermediates

Reaction with thionyl chloride gives n-valeryl chloride, a fast acylating agent used to install the pentanoyl group in pharmaceutical, agrochemical and dye intermediate synthesis - notably in certain sartan-class antihypertensive routes. Valeramide and valerate esters serve the same purpose where a gentler acylating agent is preferred.

🔗 The C3 equivalents, with the same anhydride-versus-acyl-chloride reactivity trade-offs: Propanoyl Chloride · Propionic Anhydride

🍏 3. Valerate Esters - Flavour, Fragrance & Plasticiser

Esterification inverts the odour completely. Ethyl valerate and pentyl valerate are established fruity flavour and fragrance materials used in confectionery, beverages and cosmetics, and butyl valerate serves similar duty. The molecule that is objectionable in the drum becomes an apple note at parts per million.

Heavier valerate esters - with longer-chain and polyol alcohols - function as non-phthalate plasticisers, inserting between polymer chains to reduce intermolecular attraction and raise flexibility and processability. Read the note at the top of this page before describing any of them as bio-based.

🛢️ 4. Lubricant Additives & Metalworking Fluids

Beyond base stock synthesis, valeric acid is used to make ester and amide additives, corrosion inhibitors and amine soaps for water-miscible metalworking fluids, where a short linear chain gives good water solubility and rapid wetting. Valerate esters also feature in biodegradable ester lubricant work, where hydrolytic breakdown is the desired end-of-life behaviour rather than a defect.

Valeric acid takes its name from valerian root, and it smells like it - sour, cheesy, sweaty. It is not quite as aggressive as butyric acid, but it belongs to the same family of low-molecular-weight acids whose detection thresholds sit far below any concentration that matters for occupational exposure. In practice that means the same discipline applies: a designated unloading area away from site boundaries and air intakes, closed pumped transfer rather than open pouring, a spill kit containing an odour neutraliser and not just absorbent, and dedicated site-only PPE.

🔗 We set out the full unloading and storage protocol on our C4 acid page - it applies here in full: n-Butyric Acid - odour management →

🧤 Corrosive - H314 and H318

Chemical-resistant gloves, sealed goggles plus face shield for any transfer, chemical-resistant apron and footwear. Eyewash and safety shower at the transfer point itself. Flush skin or eye contact for at least 15 minutes and seek medical attention - this causes corrosive burns and serious eye damage, not irritation.

📁 Supplied with every consignment:

📄 EU CLP-format SDS, 16 sections, with the UN 3265 n.o.s. entry and technical name completed correctly

📄 Batch COA from a CNAS-accredited laboratory - linear/branched ratio and the individual metal ion suite on request

📄 REACH registration and TSCA inventory confirmation

📄 Origin declaration stating the synthetic route - so your sustainability team has it in writing before a claim is drafted

Q1. Can I use this to make a bio-based plasticiser?

You can make the plasticiser. You cannot call it bio-based. Valerate esters are a legitimate bio-based platform when the acid comes from levulinic acid or lignocellulosic biomass, but this acid is made from a refinery butene stream and radiocarbon testing will show fossil carbon. Use it for performance and cost; do not build a certification claim on it. If a certified bio-attributed grade is what you need, say so and we will tell you honestly whether we can source it.

Q2. Valeric acid or isononanoic acid for my POE refrigeration oil?

Realistically, both. The linear C5 gives you low viscosity and refrigerant miscibility; the branched C9 gives you hydrolytic and oxidative stability that the linear chain cannot. Almost every commercial POE base stock is a mixed-acid ester for exactly this reason, and moving the C5-to-C9 ratio is how you move between ISO VG grades. We supply both from the same integrated chain, which means one supplier, one documentation set and consistent metal ion control across both feedstocks.

Q3. Why does the linear-to-branched ratio matter if assay is ≥99%?

Because the assay counts C5 acid, not which C5 acid. Residual 2-methylbutyric acid from the branched aldehyde is still a C5 carboxylic acid and still passes a total-assay test, but it esterifies to a different molecule - one with different viscosity, different pour point and different hydrolytic behaviour in your finished POE. For flavour work the difference is even starker, because branched valerate esters smell nothing like linear ones. Ask for the split; a supplier who cannot provide it does not have good control of the rectification step.

Q4. Is the odour as bad as butyric acid?

Not quite, but close enough that you should plan for it identically. Both sit in the range where the human nose detects the compound at concentrations far below anything of toxicological concern, which means an odour complaint will always arrive before a safety issue does. If your site already handles butyric acid, valeric acid needs no new infrastructure. If this is your first short-chain acid, read our handling note first - the cost of getting the unloading area wrong is measured in weeks, not hours.

Q5. Is valeric acid the same as valproic acid?

No - they are frequently confused because of the similar name. Valproic acid is 2-propylpentanoic acid, a branched C8 acid and an active pharmaceutical ingredient with its own regulatory controls. Valeric acid is the simple linear C5 acid and is not a controlled substance. If a specification or customs query references valproic acid, that is a different material and a different CAS number entirely.

Q6. What are MOQ, lead time and sample terms?

Samples ship with a full batch COA. Commercial MOQ is one 200 kg drum; IBC and ISO tank suit volume programmes and remove the empty-drum odour problem. Send target annual volume, destination port, end use (POE ester, valeryl chloride, flavour ester, plasticiser) and grade requirement, and we reply within 24 hours with pricing, documentation and - if you are going into refrigeration lubricant - the metal ion suite alongside the standard certificate.

📩 Request Price, Sample & Extended Analysis

Tell us your end use (POE base oil, valeryl chloride, flavour ester, plasticiser), grade requirement, target annual volume and destination port. We reply within 24 hours with pricing, batch COA including the linear/branched ratio and - for lubricant applications - the individual Na/Fe/Cu/Ca/Zn suite, plus the EU CLP SDS with the UN 3265 declaration completed correctly. If your project needs a certified bio-based grade, tell us and we will say so plainly rather than sell around it.