Sulfuric Acid
Sulfuric acid is the highest-volume industrial chemical produced anywhere in the world, and for good reason: fertilizer manufacture, metal processing, petroleum refining and battery production all run on it. Chelora Chemicals supplies commercial, battery and technical grades across the full concentration range your process calls for.
We supply sulfuric acid to fertilizer plants, metal finishers, refineries and battery manufacturers worldwide, by tank truck, ISO tank, IBC or drum, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 7664-93-9
- IUPAC name
- Sulfuric acid
- Molecular formula
- H2SO4
- Molecular weight
- 98.08 g/mol
- EC / EINECS
- 231-639-5
- UN Number
- UN 1830 / UN 2796
- SMILES
- OS(=O)(=O)O
- HS Code
- 2807 00*
* Confirm the exact HS heading and UN number with your customs broker — these depend on the concentration and packing you order (bulk vs. battery acid vs. spent acid).
What Sulfuric Acid is used for
Sulfuric acid is a strong, dibasic mineral acid and one of the few chemicals whose consumption is tracked as a proxy for industrial output generally — more of it is made and used than almost any other manufactured chemical. It is a powerful dehydrating agent, a strong oxidiser at high concentration and hot, and an effective proton source for reactions that need a robust acid catalyst.
In practice, most sulfuric acid is consumed captively or close to the point of manufacture: fertilizer complexes run their own acid plants, and refineries and smelters often recover it as a by-product of flue-gas treatment. What Chelora supplies is the acid that moves between plants — merchant-grade tonnage bought in by fertilizer blenders, metal finishers, battery makers and specialty formulators who do not run their own acid plant.
Concentration is the first decision
Sulfuric acid is sold across a range of strengths, and the grade name usually tells you the intended use:
- 98% (concentrated / oil of vitriol) — the standard commercial and technical grade, used as shipped or diluted on site. The reference concentration for most industrial contracts.
- 78% (chamber acid / fertilizer grade) — commonly used directly in single superphosphate (SSP) and other fertilizer manufacture.
- 62% (fertilizer / battery-adjacent grade) — an intermediate strength used in some phosphate processing routes.
- ~37% battery acid — diluted, low-iron, low-chloride acid formulated specifically for lead-acid battery electrolyte.
If your purchase order simply says "sulfuric acid", tell us the concentration, the iron and chloride limits (critical for battery grade) and the intended process, and we will confirm the correct grade before the order is placed. See our wider inorganic acids and industrial chemical range for related feedstocks.
Appearance and handling character
Commercial sulfuric acid is a colourless to slightly yellow or brownish, oily, highly viscous liquid — the "oil of vitriol" name refers directly to this texture. It is completely miscible with water in all proportions, but that dilution is strongly exothermic — acid must always be added to water, never the reverse, or the heat of dilution can flash small amounts of water to steam and spatter concentrated acid. It attacks most common metals, dissolves many organic materials, and chars carbohydrates and other organics on contact through its dehydrating action. Read the safety section before planning any handling: this is a severely corrosive material and the controls should be designed in from the outset.
| Parameter | Typical value |
|---|---|
| Appearance | Colourless to pale yellow oily liquid |
| Assay (H2SO4) | 98.0% min |
| Colour (APHA/Pt-Co) | Reported per batch |
| Iron (as Fe) | 50 ppm max (commercial) |
| Chloride | 10 ppm max (commercial) |
| Arsenic | Reported per batch |
Important: the figures above are indicative of commercial grade material and are offered for planning only. The batch certificate of analysis is the governing document. Battery-grade, catalyst-grade and analytical grade acid carry materially tighter iron, chloride and heavy-metal limits — send us your specification and we will quote against it rather than against a generic commercial grade.
| Property | Value |
|---|---|
| Physical state | Oily liquid at ambient |
| Melting / freezing point | ≈ 10 °C |
| Boiling point | ≈ 337 °C |
| Relative density | ≈ 1.84 |
| Viscosity | ≈ 24 cP at 25 °C |
| Water solubility | Fully miscible (exothermic) |
| pH (1% solution) | < 1 (strongly acidic) |
| Odour | Odourless (mist may irritate) |
Physical constants compiled from public reference data for CAS 7664-93-9 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this acid to work
Sulfuric acid's demand base is enormous and diverse — fertilizer alone accounts for the largest single share, but metals, energy and chemical manufacturing all depend on it too.
Fertilizer manufacture
The largest single outlet worldwide. Sulfuric acid digests phosphate rock to make single superphosphate (SSP) and, via phosphoric acid, triple superphosphate and DAP/MAP compound fertilizers. It is also used to make ammonium sulfate directly.
- Phosphate rock digestion
- Ammonium sulfate production
- See our fertilizer intermediate range
Metal pickling & plating
Used to strip mill scale and oxide from steel before rolling, coating or galvanising, and as an electrolyte and cleaning bath component in electroplating and metal surface preparation lines.
- Steel pickling before hot-dip galvanising
- Electroplating bath chemistry
- Non-ferrous metal refining
Lead-acid batteries
Diluted, low-iron, low-chloride battery-grade acid is the electrolyte in every lead-acid battery — automotive, industrial and backup power. Trace metal limits here are far tighter than for commercial acid, since impurities shorten battery life.
- Automotive & industrial battery electrolyte
- Battery assembly and re-filling lines
- Tight iron and chloride specification
Petroleum refining
Used as a catalyst in alkylation units to make high-octane alkylate for gasoline blending, and in acid treatment of lubricating oil fractions. Spent alkylation acid is typically regenerated rather than discarded.
- Alkylation catalyst for motor fuel
- Lubricant oil purification
- Refinery wastewater neutralisation
Dyes, detergents & textiles
A feedstock for sulfonation reactions used in dye intermediates, linear alkylbenzene sulfonate (LABS) detergent manufacture, and mercerising and finishing steps in textile processing.
- Sulfonation chemistry for dyes and LABS
- Textile finishing baths
- Pulp and paper processing
Contract & scheduled supply
Fertilizer and metals plants run continuous or campaign production and consume large, steady tonnages. Most buyers want acid delivered against a running-consumption schedule rather than as one-off spot cargoes.
- Annual contracts with scheduled call-off
- Tank-truck and ISO tank delivery programmes
- Second source held in reserve
How we supply Sulfuric Acid
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. We own no acid plant — and for a bulk commodity acid like this one, that independence means we buy from whichever qualified producer has the concentration, purity and delivery window your plant needs, rather than pushing you whatever a captive unit happens to have on hand.
Instead we place your order with the source that best matches your assay, your iron and chloride limits, your price point and your delivery window.
We keep a second qualified source on this line. When a plant goes down for a turnaround, or transport capacity tightens ahead of the fertilizer season, your supply switches source rather than stalling a production line that depends on continuous acid feed.
- Concentration confirmed before quoting. We confirm whether you need 98%, 78%, 62% or battery-grade acid before a price is issued — the wrong strength on a bulk delivery is an expensive mistake to unwind.
- Batch COA shared before dispatch. You approve assay, colour, iron and chloride content against your own spec while the acid is still in tank at origin.
- Hazard status stated up front. This material is severely corrosive to skin, eyes and metals, and we say so at enquiry stage — not buried in a document pack that arrives with the tanker.
- Compatible transport arranged. Lined tanks, dedicated tankers and compatible IBCs are confirmed before loading — sulfuric acid attacks many common construction materials.
- Packing chosen for your receiving setup. Bulk tanker, ISO tank, IBC or drum — we plan the format around how your plant actually unloads and stores acid.
- Export machinery handled in-house. Hazard classification, UN-approved tanks and packaging, labelling, freight booking and customs paperwork are ours to manage.
- Consolidated programmes available. Combine sulfuric acid supply with other bulk intermediates from our range under one contract and one point of contact.
Moved the way your plant receives it
Sulfuric acid is a bulk commodity acid, and the format you take it in drives your landed cost and your unloading effort more than almost any other variable. Tell us your receiving infrastructure and we will quote the format that fits it.
Dedicated bulk tankers
Road tankers lined for concentrated acid service, delivering directly into your storage tank. The default for continuous-consumption plants near our loading points.
ISO tank containers
Lined ISO tanks for sea and combined road/rail movement, giving you container-level tracking and no drumming or decanting losses on long international transits.
Lined IBCs
Acid-compatible IBC totes for mid-volume users without bulk tank storage — common for plating shops, laboratories and smaller fertilizer blenders.
HDPE-lined drums
UN-certified drums for laboratory, pilot-scale and low-volume commercial use, or for destinations without bulk unloading infrastructure.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to. Ocean, road and rail freight arranged end-to-end with dangerous-goods documentation filed before booking.
Running-consumption supply
Fertilizer and metals plants consume acid continuously. We contract annual tonnage and schedule tanker deliveries against your actual burn rate rather than shipping in large, irregular lots.
Handle this as a severely corrosive acid
This is the point on the page that matters most. Concentrated sulfuric acid causes severe and often deep burns on contact with skin or eyes, reacts violently and exothermically with water and many bases, and attacks most common construction metals. The summary below is orientation only — the safety data sheet supplied with your consignment is the authoritative document and should govern your risk assessment, PPE selection and emergency planning.
Classified hazards
H314Causes severe skin burns and eye damage.H290May be corrosive to metals.EUH071Corrosive to the respiratory tract.
Hazard statements reflect the harmonised GHS classification commonly published for CAS 7664-93-9 at concentrated strength; dilute solutions carry a reduced classification that your SDS will state. Always read the SDS issued with your specific batch and concentration.
Spill & emergency orientation
Plan your response before the tanker connects, not after a hose fails. The points below are orientation for your emergency planners — sections 4, 5 and 6 of the SDS are the authoritative instructions and should be posted at the point of use.
- Never add water to the acid. Dilution is strongly exothermic and can flash-boil, spattering concentrated acid. Always add acid slowly to water, with stirring and cooling, never the reverse.
- Contain, don't wash away. Bund and neutralise a spill with soda ash or lime in line with the SDS before any water is applied; never let acid reach a drain or watercourse untreated.
- Assume immediate tissue damage on contact. Flush exposed skin or eyes with copious running water for at least 15–20 minutes and seek medical attention regardless of apparent severity.
- Ventilate for mist and fumes. Concentrated acid can generate an acidic mist that is corrosive to the respiratory tract, particularly during transfer operations.
- Check metal compatibility before storage. Sulfuric acid reacts with many metals to liberate flammable hydrogen gas — confirm tank and fitting materials before filling.
Storage
- Dedicated, compatible tankage, typically lined carbon steel, HDPE or FRP depending on concentration — mild steel is acceptable for high-concentration, low-water acid but is attacked rapidly by dilute solutions.
- Bunded and roofed storage, away from incompatible materials and from areas prone to rainwater ingress, which would dilute and accelerate corrosion of the tank.
- Segregate from bases, most metals, water-reactive materials and organic matter, including wood, paper and combustible dusts, which it chars and can ignite through its dehydrating and oxidising action.
- Access-controlled bunded area with acid-resistant flooring and a dedicated neutralisation pit for wash-down and spill response.
- Shelf life is effectively indefinite in sealed, compatible storage — the acid itself does not degrade, but tank and fitting corrosion over time is the real limiting factor.
Handling & PPE
- Design exposure out where you can. Closed transfer via pump and dedicated hard-piped connections beats manual decanting every time for a severely corrosive liquid.
- Full-face shield and chemical-resistant apron over acid-resistant gloves and boots for any manual handling, drumming or connection/disconnection work.
- Emergency eyewash and safety shower within immediate reach of every handling point — not down the corridor.
- Never wear contact lenses when handling concentrated acid; acid mist can be trapped behind a lens and worsen an eye injury.
- Train for the specific reactivity. Operators should understand the dilution rule and the hydrogen-gas risk with metals before they are authorised to handle this acid unsupervised.
Transport
Sulfuric acid moves as regulated cargo under UN 1830 (concentrated, >51% acid) or related entries depending on concentration and packaging. We classify each consignment, use compatible tanks and UN-approved packaging, and file the dangerous-goods declaration before booking. The applicable UN number, class and packing group are stated on your shipping documents and SDS — ask us for the current DG paperwork when you plan the shipment.
What travels with every consignment
A bulk acid shipment is only as good as the file that travels with it. Verifying what the source plant sends is precisely the work you are buying from a supplier.
Certificate of Analysis
Batch-specific assay, colour, iron, chloride and heavy-metal content — checked against your purchase specification before the tanker is released.
GHS Safety Data Sheet
Full 16-section SDS in GHS format covering hazards, exposure controls, handling, storage, spill response, toxicology and disposal — issued in the language your destination requires.
Dangerous Goods Declaration
UN number, hazard class, packing group and IMDG or road/rail dangerous-goods declaration prepared and filed before the tanker or container is booked.
Certificate of Origin
Chamber-attested where required, plus preferential-origin forms where a trade agreement gives your import duty relief at the destination.
Third-party inspection
SGS, Intertek or Bureau Veritas sampling and tank-gauging arranged on request before loading, giving you independent verification of concentration and quantity shipped.
Retained & pre-shipment samples
Pre-shipment samples carry the same COA as the commercial lot, so what your laboratory qualifies is exactly what arrives. Retention samples held against the batch.
Three properties, one workhorse molecule
Sulfuric acid's usefulness comes down to three overlapping properties: it is a strong acid, a powerful dehydrating agent, and — at high concentration and temperature — an oxidiser. Which property your process is exploiting determines which specification actually matters.
As a strong acid
Fully dissociates in water to donate protons readily, making it the acid of choice for digesting phosphate rock, pickling steel and catalysing alkylation.
As a dehydrating agent
Strong affinity for water drives its use in drying gases, in organic synthesis dehydrations, and explains why it chars organic matter and generates heat on dilution.
As an oxidiser
Hot, concentrated acid oxidises many metals and non-metals, a property exploited in some metal refining and cleaning processes but also the reason it attacks storage tanks.
Finish to grade
Contact-process acid is diluted, filtered and standardised to whatever concentration and purity the end market requires — fertilizer feed, battery electrolyte or reagent grade.
Why concentration and trace metals carry through the process
Because sulfuric acid is used across such different processes, the impurity that matters most changes completely depending on the outlet:
- Iron content is largely irrelevant to a fertilizer digestion but can ruin a battery's cycle life or discolour a plating bath — battery-grade limits are far tighter than commercial-grade.
- Chloride content accelerates pitting corrosion in stainless equipment and is tightly limited wherever the acid contacts stainless steel process vessels.
- Water content (i.e. concentration) is the single most important variable in alkylation catalysis, where even small dilution changes reaction selectivity.
- Colour and organic residue matter in textile and dye applications, where a coloured or contaminated acid can carry through to the finished product.
That is the reason we quote against your written specification rather than a generic "98% technical" grade, and the reason the batch COA is shared for approval before dispatch rather than sent with the invoice.
| Grade | Principal outlet |
|---|---|
| 98% Commercial / Technical Standard reference grade | Fertilizer digestion Metal pickling General industrial use |
| Battery grade (~37%) Low iron / low chloride | Lead-acid battery electrolyte |
| Alkylation-grade concentrated High purity, controlled water content | Refinery alkylation catalyst |
If your process calls for a grade not listed here, send us the specification and we will source against it — see our full inorganic chemicals range for related feedstocks and co-products.
What actually moves the price of this commodity acid
Sulfuric acid pricing is unusually tied to smelter and refinery by-product output as well as to fertilizer demand. Knowing what drives the quote helps you time a purchase.
Fertilizer season demand
Acid demand spikes ahead of each planting season as phosphate fertilizer plants ramp output, tightening merchant acid availability and freight capacity.
- Quote early for pre-season tonnage
- Spot buying at peak season costs more
- Contracted call-off smooths the exposure
Smelter by-product supply
A significant share of merchant acid is recovered from copper, zinc and lead smelter flue-gas treatment. Smelter maintenance shutdowns or ore grade changes ripple through to acid availability.
- Smelter output is not acid-demand driven
- Regional supply can swing quickly
- We track multiple source regions
Freight is a large share of cost
Sulfuric acid is a low-value-per-tonne, high-volume liquid, so freight and tank rental can represent a large share of landed cost — often more than the ex-works acid price itself over long distances.
- Compare on landed cost, not ex-works
- Regional sourcing often beats a lower ex-works price
- We quote FOB, CIF, CFR or DDP as you prefer
Pack format
Cost per tonne falls sharply from drums to IBCs to bulk tanker. A plant that can accept bulk tanker delivery pays materially less per tonne than one relying on drummed acid.
- Bulk tanker is cheapest per tonne
- Drummed acid suits low-volume or remote sites
- We help plan the tank investment case
Regulatory & environmental cost
Emissions controls at acid plants and tightening transport regulation for corrosive bulk liquids add to production and logistics cost over time, and that cost sits inside the price.
- Handling obligations vary by jurisdiction
- Some routes require specific tank certification
- We check destination rules before quoting
Source availability
A refinery turnaround, a smelter outage or seasonal freight congestion can take capacity offline at short notice. Single-sourced buyers feel this hardest.
- We hold a second qualified source on this line
- Qualify the alternate before you need it
- Ask us about dual-source contracts
| If your end use is… | Specify |
|---|---|
| Fertilizer manufacture | 78% or 98%, colour and arsenic reported |
| Battery electrolyte | ~37%, tight iron and chloride limits |
| Metal pickling / plating | 93–98%, iron and heavy-metal limits |
| Refinery alkylation | 98%+, controlled water content |
| Laboratory / R&D | Small pack, ACS/analytical grade, full COA |
Not sure which column you are in? Describe the process you are running and our technical desk will recommend the grade — including telling you when a cheaper commercial grade would do the job just as well.
Support that goes beyond shipping the tanker
What our technical desk will do
- Match a grade to your process. Tell us the step you are running and we will recommend the concentration and purity — and say so plainly when a lower grade would add nothing.
- Be straight about the hazard profile. We state the corrosivity classification at enquiry stage so your EHS team can price the controls into the decision, rather than meeting it for the first time on the tanker placard.
- Advise on tank and material compatibility for your site conditions — the right lining and metallurgy depends heavily on concentration and temperature.
- Review your specification before it goes into a contract, so you are not locked into an iron or chloride limit that no plant can consistently hit.
Regulatory & compliance notes
- Transport regulation is strict and concentration-dependent. UN classification, packing group and permitted tank types vary by concentration — confirm the current requirements before booking a shipment.
- Import controls vary by destination. Some jurisdictions apply registration, licensing, or storage-permit requirements to bulk corrosive liquids. We check destination rules before quoting, not after you have raised the PO.
- Chemical inventory listings differ between regions. Confirm your obligations under the applicable inventory regime for your import volume — we will supply the identity data you need for that filing.
- Site storage permits for bulk corrosive liquid tanks are typically required by local environmental or occupational safety authorities — confirm this with your facilities and EHS team ahead of installing new tankage.
None of the above is legal advice — your own regulatory affairs team owns the final compliance position for your import and your workplace. What we commit to is giving you accurate product identity data, an honest statement of the hazard classification and complete documentation to work from.
From enquiry to delivered tanker
Send the specification
Product name or CAS 7664-93-9, the concentration and impurity limits you work to, quantity, pack preference and destination.
Receive a firm quote
Pricing, lead time, packing and Incoterm confirmed in writing within 24 hours — our sourcing desk is staffed around the clock.
Qualify and approve
Sample dispatched if you are qualifying a new source. Batch COA shared for your approval before the tanker or container is released.
Ship and track
DG classification filed, compatible tanks and freight booked, export documents issued, and the consignment tracked through transit and clearance to your plant.
Often bought alongside this acid
Consolidate several intermediates onto one shipment and one invoice. These are the related acids, oleum and inorganic chemicals our fertilizer, metals and chemical manufacturing customers most often order alongside sulfuric acid — see the full range on our products page.
What buyers ask us about Sulfuric Acid
What concentration do you supply?
Is sulfuric acid dangerous to transport and store?
Why can't I just add water to the acid to dilute it myself?
What is the minimum order quantity?
How long does delivery take?
Can you supply battery-grade acid specifically?
What storage tank material should I use?
Does the acid degrade or lose strength in storage?
Is this a dangerous good? What paperwork comes with it?
- Batch certificate of analysis
- GHS-format safety data sheet
- Dangerous-goods declaration with UN number, class and packing group
- Commercial invoice, packing list and bill of lading or consignment note
- Certificate of origin and any destination-specific forms
Do you supply to my country?
Do you manufacture this yourself?
Can you hold stock against a production plan?
Request pricing on Sulfuric Acid
Send your required concentration, quantity, pack format and destination. Our sourcing desk is available 24 hours a day, 7 days a week, and comes back with pricing, lead time and packing options — whether that is a single drum for laboratory qualification or a contracted tanker programme for the year.