N-Butyric Acid (Butanoic Acid) — CAS 107-92-6, ≥99%

n-Butyric Acid (Butanoic Acid) - CAS 107-92-6

Assay ≥99% GC · Water ≤1000 mg/kg · Pt-Co ≤15 · 50,000 t/a designed capacity · Propylene-to-acid integrated chain

👃 Read this before you place the order: the odour is the hardest part of handling butyric acid.

Butyric acid is the compound responsible for the smell of rancid butter and vomit, and human detection thresholds for it are reported down in the parts-per-billion range. That is not a comfort issue. It means a quantity far too small to register on any workplace exposure monitor is more than enough to make a warehouse unusable, trigger complaints from neighbouring businesses, and in some cases bring a local environmental officer to your gate.

What experienced buyers do before the first container arrives: designate a dedicated unloading and storage area away from the site boundary, offices and any HVAC air intake. Use closed transfer - pumped, not poured. Keep a spill kit with absorbent plus an odour-neutralising agent, not just absorbent. Issue dedicated PPE and overalls that stay on site, because clothing retains the odour through a domestic wash. Treat emptied drums as still odorous and store them outdoors pending rinse and disposal.

We tell every first-time buyer this. A supplier who sells you butyric acid without mentioning it is either inexperienced or is leaving you to find out the expensive way.

⚠️ Two parameters you should ask for that are not on the standard certificate.

Isobutyric acid content. Propylene hydroformylation produces both n-butyraldehyde and isobutyraldehyde; rectification separates them, but the residual iso fraction carries through oxidation into the acid. For tributyrin and butyrate salt production the iso isomer is largely inert ballast, but for flavour work it changes the profile, and for pharmaceutical intermediate synthesis it becomes an impurity you have to chase downstream. The ≥99% assay figure does not by itself tell you the n/iso split - ask for it explicitly and we will report it.

Heavy metals, arsenic and residue on ignition. The specification above is an industrial grade. It is not, and does not claim to be, an FCC food-grade certificate. See the grade section below.

🧫 Fermentation. Anaerobic bacterial fermentation of sugar or starch. Gives a bio-based product that can carry a natural-origin claim for flavour use, but at higher cost, lower titre and with a different impurity spectrum.

🛢️ Oxo synthesis from propylene. Hydroformylation to butyraldehyde followed by controlled oxidation. Higher purity, tighter batch consistency, far better economics at scale. This is our route. It cannot carry a natural-origin flavour claim - if that is what you need, say so at enquiry and we will tell you plainly that this is the wrong product.

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

02Refining - crude processed to yield propylene and butene

03Hydroformylation - olefin plus syngas to the corresponding aldehyde

04Rectification - high-purity n-butyraldehyde separated from the iso isomer

05Oxidation - aldehyde oxidised to n-butyric acid

🐖 1. Feed Additives - roughly 90% of demand

Almost all n-butyric acid ends up as a feed additive precursor, and the reason is regulatory: as antibiotic growth promoters were withdrawn from feed across the EU and later China, producers needed alternatives that support gut health in pigs and poultry without an antibiotic. Butyrate is the primary energy substrate for colonocytes and supports intestinal barrier integrity, which put it at the centre of that shift.

Why the derivatives rather than the free acid: dosed directly, butyric acid is absorbed high in the digestive tract and never reaches the hindgut where it is needed - and it would make a feed mill unworkable. So it is converted into tributyrin, which releases butyrate slowly under lipase action, or into sodium, calcium or magnesium butyrate, usually coated or microencapsulated to survive to the lower gut.

Theoretical stoichiometric figures at 100% conversion - use them to sanity-check a quotation, then add your own yield loss.

🧪 2. Butyric Anhydride & Butyryl Chloride

Dehydration gives butyric anhydride, used to make butyrate esters and - importantly - cellulose acetate butyrate, the coatings polymer prized for flow control and rapid solvent release. Treatment with thionyl chloride or phosphorus trichloride gives butyryl chloride, a fast acylating agent for pharmaceutical and dye intermediate synthesis.

🔗 We already supply the C3 equivalents of both, with the same reactivity trade-offs: Propionic Anhydride · Propanoyl Chloride - if you need the C4 derivatives rather than the acid, ask.

🍍 3. Butyrate Esters - Flavour, Solvent, Plasticiser

Esterification transforms the odour completely. Ethyl butyrate smells of pineapple, methyl butyrate of apple, butyl butyrate of pear - all standard flavour and fragrance materials for confectionery, baked goods and beverages. The heavier esters double as solvents, coalescents and plasticiser components in coatings and adhesives.

Butyric acid itself, at trace level in food-grade form, contributes the sour dairy note in cheese, butter and cream flavour systems. Reported taste characteristics at 250 ppm run acidic, sour, cheesy and creamy with a fruity nuance - the same molecule that is objectionable in bulk is essential in parts per million.

💊 4. Pharmaceutical & Specialty Intermediates

Butyramide as a pharmaceutical intermediate; butyrate salts and prodrugs investigated for gastrointestinal applications; and the butyryl group installed generally across API and agrochemical synthesis where a four-carbon acyl chain is required. Pharmaceutical use requires a tighter specification than the industrial grade shown above - discuss requirements before ordering.

The specification on this page is an industrial grade. Assay, water and colour are the right controls for tributyrin synthesis, butyrate salt production, ester manufacture and anhydride or acyl chloride feedstock. For those uses it is exactly what you want, and paying for a tighter grade buys you nothing.

It is not a food-grade certificate. Direct flavour use requires a Food Chemicals Codex specification with heavy metals, arsenic, residue on ignition and readily carbonisable substances controlled, plus the appropriate food-contact and flavouring-substance documentation. Feed-additive registration in your market may impose its own requirements again.

Tell us the end use at enquiry stage. If you need FCC or feed-grade documentation we will confirm whether it can be supplied against your specification before quoting, rather than shipping industrial material with an optimistic certificate attached.

🧤 Corrosive - H314, causes severe skin burns and eye damage

Chemical-resistant gloves (rubber, PVC or butyl - check breakthrough time against your contact scenario), sealed goggles plus face shield for any transfer operation, chemical-resistant apron and footwear. Eyewash and safety shower within immediate reach of the transfer point, not down the corridor. Flush skin or eye contact with water for at least 15 minutes and seek medical attention - this is a corrosive burn, not an irritation.

📁 Supplied with every consignment:

📄 EU CLP-format SDS, 16 sections, with UN 2820 transport details completed

📄 Batch COA from a CNAS-accredited laboratory - with the n/iso ratio reported on request

📄 REACH registration and TSCA inventory confirmation

📄 Non-GMO, allergen-free and BSE/TSE-free declarations for feed and food chain customers

📄 Odour management and unloading guidance note for first-time buyers

Q1. Is the odour really that bad, or is this a formality?

It is really that bad, and it is the single most common reason a first-time butyric acid buyer has a problem. The issue is not toxicity - the exposure limits are not the constraint. It is that the detection threshold sits so far below any hazardous concentration that you will have an odour complaint long before you have a safety one. Sites that handle it without incident are the ones that decided where to put the drums before the container arrived. Ask us for the handling note; we send it whether or not you request it on a first order.

Q2. Should I buy butyric acid or buy tributyrin and butyrate salts directly?

Buy the acid only if you are making the derivatives. If you are a feed producer wanting butyrate in a ration, you want the finished tributyrin or a coated butyrate salt - the free acid will not survive to the hindgut and will make your mill unpleasant to work in. If you are a derivative manufacturer, the acid is your feedstock and the stoichiometry table above tells you roughly how much you need per tonne of product. We would rather point you to the right position in the chain than sell you something you cannot use.

Q3. Synthetic or fermentation-derived - does it matter for my application?

For feed additive and industrial derivative synthesis, no - the synthetic oxo route gives higher purity and better batch consistency at lower cost, and the butyrate ion reaching the animal is identical either way. It matters if you need a natural-origin flavour designation, where regulations in some markets require the material to be derived from a natural source. This product is synthetic and cannot carry that claim. If your customer's specification says natural, we are not the right supplier for that line and will say so.

Q4. Why does the isobutyric acid content matter?

It depends entirely on what you are making. For tributyrin and butyrate salts it is mostly inert weight - you pay for it and it does not contribute butyrate, so it affects your yield calculation but not your product quality. For flavour esters it changes the sensory profile, since isobutyrate esters smell different from n-butyrate esters. For pharmaceutical intermediates it is an impurity that propagates through your synthesis and has to be removed later, which is far more expensive than specifying it at purchase. Tell us your use and we will report the figure.

Q5. Can I store it in a standard carbon steel tank?

No. Butyric acid attacks carbon steel and the resulting iron pickup will show as colour drift and will carry into your downstream product - a real problem if you are making a light-coloured ester or a food-chain derivative. Use 316L stainless, HDPE, PP or a properly lined vessel, and check pump seals and gaskets as carefully as the tank itself.

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 are available for volume programmes, and bulk is usually the better economics once you are past a few hundred tonnes a year - it also removes the empty-drum disposal problem, which with this product is not trivial. Send target annual volume, destination port, end use and grade requirement and we will reply within 24 hours.

📩 Request Price, Sample & Handling Guidance

Tell us your end use (tributyrin, butyrate salts, esters, anhydride, acyl chloride, flavour), grade requirement, target annual volume and destination port. We reply within 24 hours with pricing, batch COA including the n/iso ratio, EU CLP SDS with UN 2820 details completed, and the odour management note. If your application needs a food or feed grade we will confirm what can be certified before quoting.