Sulfuric Acid H₂SO₄ · CAS 7664-93-9
Chelora Chemicals is a supplier of Sulfuric Acid across industrial, fertilizer, battery and laboratory-reagent grades, from 29% battery-strength solutions to 98% concentrated acid. Every consignment leaves with a batch-specific COA and the current SDS.
Also known as: Oil of Vitriol · Hydrogen Sulfate · Battery Acid (dilute grades)
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Price, lead time and a sample COA for Sulfuric Acid at your required strength, usually within one working day. We ship worldwide.
Request a Quote Email the DeskDocumentation
- Batch-specific COA (assay, specific gravity, iron & chloride)
- Safety Data Sheet (SDS)
- Dangerous-goods transport documents (Class 8)
- Third-party inspection on request
- Certificate of origin
What is Sulfuric Acid?
Sulfuric Acid, formula H₂SO₄, is a strong mineral acid and one of the highest-volume industrial chemicals produced worldwide. At room temperature it is a dense, oily, colourless to slightly yellow liquid, fully miscible with water in an exothermic reaction, with concentrated grades reaching a specific gravity around 1.84.
Its value comes from its strength as a non-oxidising acid (in dilute form) and oxidising agent (concentrated and hot), its powerful dehydrating ability, and its role as the single largest-tonnage chemical feedstock behind fertilizer, metal processing, and countless downstream syntheses. It is supplied across a range of concentrations, each suited to a different industrial use.
Commercially, it is produced by the contact process: burning sulfur or roasting sulfide ores to sulfur dioxide, catalytically oxidising this to sulfur trioxide, and absorbing the trioxide into water or existing acid to build concentration.
It ships as a Class 8 corrosive, with hazard severity scaling directly with concentration — dilute battery-grade acid and 98% concentrated acid both require corrosive-liquid handling, but the latter demands substantially more stringent controls.
Why Sulfuric Acid specifically
- The workhorse industrial acid. Used at greater tonnage than any other manufactured chemical, principally for phosphate fertilizer production.
- A strong dehydrating agent. Concentrated sulfuric acid removes water from organic and inorganic substrates, a property exploited across process chemistry.
- The specific concentration your process needs. Battery, fertilizer, pickling and laboratory-reagent applications each call for a different strength, and Chelora supplies across the full commercial range.
- Established, scalable supply. Produced by the well-understood contact process at large and consistent capacity worldwide.
How Sulfuric Acid is Manufactured
Sulfuric Acid is made at industrial scale via the contact process, so supply tracks installed sulfur-burning and catalytic-conversion capacity rather than a specialty fine-chemical production line.
- Sulfur burning or ore roasting. Elemental sulfur is burned, or sulfide ores are roasted, to generate sulfur dioxide gas.
- Catalytic oxidation. The sulfur dioxide is catalytically oxidised over a vanadium pentoxide catalyst to sulfur trioxide.
- Absorption. Sulfur trioxide is absorbed into water or existing sulfuric acid to form concentrated acid, with heat recovered from the exothermic steps.
- Dilution to grade. The concentrated acid is diluted with water to the target commercial strength (29%, 49%, 78%, 93% or 98%, among others).
- Quality release. Assay, specific gravity and trace-metal content are confirmed against specification before the batch is released.
Typical Commercial Specification
Figures below are representative of commercial-grade sulfuric acid at common commercial strengths. Tell us your downstream process and the concentration you need, and we will advise on the specification to order against.
| Parameter | Typical Value |
|---|---|
| Appearance | Clear to slightly coloured oily liquid |
| H₂SO₄ concentration | 29% / 49% / 78% / 93% / 98% (to order) |
| Specific gravity (98% grade) | About 1.84 |
| Iron (Fe) content | To grade, low ppm |
| Chloride content | To grade, low ppm |
| Colour | Water-white to pale straw, to grade |
Physical & Chemical Properties
| Property | Value |
|---|---|
| Chemical formula | H₂SO₄ |
| Molecular weight | 98.08 g/mol |
| Appearance | Clear to slightly coloured oily liquid |
| Melting point (98%) | About 10 °C |
| Boiling point (98%) | About 337 °C |
| Specific gravity (98%) | About 1.84 |
| Water solubility | Fully miscible (exothermic) |
| Incompatibilities | Water (add acid to water, never the reverse), strong bases, most metals, organic materials, oxidisers |
Behaviour in the process
Sulfuric Acid's reactivity pattern is what industrial buyers rely on:
- Strong dehydrating action. Concentrated acid removes water from organic substrates and hydrates, a property used throughout process chemistry.
- Exothermic dilution. Mixing with water releases substantial heat; acid is always added to water, never the reverse, to avoid violent spattering.
- Metal reactivity. Reacts with most base metals, generating hydrogen gas with dilute acid and sulfur dioxide with hot concentrated acid.
- Non-volatile, high-boiling acid. Its low volatility makes it useful for displacing more volatile acids from their salts.
Sulfuric Acid and Related Industrial Acids
Sulfuric Acid is one of several bulk mineral acids, and the choice between them depends on the process chemistry and the anion the application needs.
| Material | Character | When it is the right choice |
|---|---|---|
| Sulfuric Acid | Strong, non-volatile, dehydrating | Fertilizer, metal pickling, battery, general industrial processes |
| Hydrochloric Acid | Strong, volatile | Processes needing a non-oxidising, chloride-based acid |
| Nitric Acid | Strong, oxidising | Processes needing an oxidising acid or nitrate anion |
| Phosphoric Acid | Medium-strength, non-volatile | Food-grade, fertilizer or corrosion-inhibiting applications |
Stated plainly: the choice of industrial acid is dictated by the target process's chemistry and the anion it requires — a route built around sulfate chemistry needs sulfuric acid, and a different requirement calls for a different acid.
Industries We Supply Sulfuric Acid To
The same acid feeds a fertilizer plant, a metal-finishing shop and a battery manufacturer. What changes is the grade, the concentration and the documentation each requires.
Where Sulfuric Acid is Used
Sulfuric Acid is bought across a wide span of concentrations and purities for very different end uses. These are the downstream applications our customers use it for.
In fertilizer and bulk industrial chemistry
Sulfuric acid is reacted with phosphate rock to produce phosphoric acid, the feedstock for superphosphate and other phosphate fertilizers, and is used at scale across metal processing and bulk chemical manufacture. Concentration and trace-metal purity matter because they determine both reaction efficiency and product quality downstream.
In battery and laboratory-reagent applications
Dilute, high-purity grades serve as battery electrolyte and laboratory reagent, where trace-metal limits are considerably tighter than for bulk industrial acid.
Need a specific concentration or packing format?
Tell us the concentration and grade you need, your downstream process, the packing or tanker format you can receive and the annual quantity. We will come back with a price, a lead time and a sample COA.
Quality Control & Testing
Every lot is released against a batch-specific Certificate of Analysis, with trace-metal content reported alongside the main assay because both affect downstream process and product quality.
- H₂SO₄ concentration — by titration, the primary grade measure.
- Specific gravity — a fast, continuous check correlated with concentration.
- Iron and chloride content — reported because trace metals affect battery performance and catalytic processes.
- Colour and clarity — a visual purity indicator, particularly for reagent-grade material.
Common Process Problems & Likely Causes
When this acid causes trouble, it is usually a concentration mismatch or trace-metal contamination. This table is the shortcut our technical desk works through before anyone opens a complaint file.
| Symptom | Likely cause | What to check |
|---|---|---|
| Poor battery performance | Iron or chloride contamination | Trace-metal figures on the COA |
| Unexpected reaction yield | Concentration mismatch against process design | Assay and specific gravity on the COA |
| Discoloured product | Organic contamination or oxidisable trace impurities | Colour specification and impurity profile on the COA |
| Excess heat on dilution | Mixing order reversed (water added to acid) | Confirm handling procedure: always add acid to water |
Packaging, Storage & Shipping
- Standard packing. HDPE carboys and drums (25 – 250 kg), IBC totes, and bulk road tanker or ISO tank container shipments for larger volumes.
- Material compatibility. Store and transport in acid-resistant containers; avoid mild steel, most other metals and organic materials.
- Mixing procedure. Always add acid to water, never water to acid, to avoid violent exothermic spattering.
- Temperature control. Store at ambient temperature away from freezing (concentrated grades can crystallise) and away from incompatible materials.
- Shelf life. Effectively indefinite in sealed, compatible containers; not combustible itself but highly reactive with many materials.
- Transport classification. UN 1830 (concentrated, >51%), Class 8, Packing Group II. ADR, IMDG, IATA and DOT requirements apply to packing, labelling and routing; dilute grades may fall under different UN entries.
Hazards & Safe Handling
Sulfuric Acid is a strong corrosive. It causes severe skin burns and eye damage on contact, and concentrated grades react violently and exothermically with water, so standard corrosive-liquid precautions and good plant practice apply throughout handling, with severity scaling with concentration.
- Skin and eye contact. Chemical-resistant gloves, a face shield and acid-resistant apron are standard practice; flood affected areas with water immediately and seek medical attention.
- Dilution heat. Always add acid to water, never the reverse; dilution of concentrated acid releases substantial heat.
- Inhalation. Mist or vapour from concentrated or hot acid is highly irritating; use adequate ventilation and respiratory protection where mist is generated.
- PPE. Chemical-resistant gloves, goggles or face shield, and acid-resistant protective clothing as a baseline for handling concentrated grades.
- Spill response. Neutralise small spills with an appropriate base (e.g., soda ash or lime) under controlled conditions; never apply water directly to a concentrated-acid spill without a controlled dilution plan.
Regulatory & Compliance Notes
Sulfuric Acid is a globally registered bulk industrial chemical shipped as a Class 8 corrosive. Because obligations differ by territory, concentration and use, the notes below are orientation rather than legal advice — confirm your own position with your regulatory adviser.
- GHS classification. Classified as corrosive to metals and causing severe skin burns and eye damage; the SDS carries the full hazard statements for your grade and concentration.
- REACH and chemical inventories. Registered under EU REACH and listed on major chemical inventories worldwide.
- Dangerous goods transport. UN 1830 for concentrated grades, Class 8, Packing Group II; dilute grades may carry a different UN entry. ADR, IMDG, IATA and DOT requirements apply to packing, labelling and routing.
- HS code. Commonly declared under the sulfuric acid and oleum heading; confirm the exact tariff line with your customs broker for your jurisdiction.
- Quality agreements. Battery, fertilizer and reagent-grade buyers commonly expect documented trace-metal limits and change control. Tell us what your agreement requires.
We Supply Sulfuric Acid Worldwide
Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship Sulfuric Acid from India and from partner sources to customers across Asia, Europe, the Middle East, Africa, and North and South America, handling the export documentation, bulk logistics and freight so the material arrives ready to use.
- Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
- Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other ports arranged as routing allows.
- Documentation. Commercial invoice, packing list, certificate of origin, COA and SDS issued as a complete set.
- Flexible volumes. From drum trial quantities up to bulk tanker and ISO-container shipments on a supply contract.
- Supply continuity. Because we are independent of any one producer, a plant turnaround or a shipping disruption at one source does not have to become your stock-out.
Buying Sulfuric Acid from Chelora
We are an independent sourcing and supply partner. For this product that means settling three things at enquiry: the concentration and grade your process needs, the packing or tanker format, and the quantity you are buying.
- Documentation on every lot. Batch-specific COA with assay, specific gravity and trace-metal content, plus the current SDS.
- Analysis before commitment. Representative analysis shared ahead of a commercial order so your lab can qualify the material.
- Quantities. Drum trial quantities through to bulk tanker shipments on contract supply.
- Inspection. Independent third-party inspection available at loading when the contract requires it.
- Related industrial acids. Hydrochloric, nitric and phosphoric acid alongside this product from one supplier.
How ordering works
- Send the enquiry. Concentration, grade, quantity, destination port and the Incoterm you buy on. If you have a spec sheet, attach it — it saves a round trip.
- We quote. Price, lead time, packing or tanker format and a sample COA, normally within one working day.
- Qualify the supply. For first orders or battery- and reagent-grade applications, we share the analysis so your technical team can sign off before you commit.
- Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
- Allocation and QC. Material allocated and released against a batch-specific COA, with an independent inspection where the contract calls for it.
- Ship and document. Packed or loaded, labelled and shipped with the full export document set, and tracked through to arrival.
Sulfuric Acid — Common Questions
The questions our technical desk is asked most often about Sulfuric Acid. If yours isn't here, call or email and you will reach someone who knows the chemistry.
What is the CAS number of Sulfuric Acid?
The CAS number for Sulfuric Acid is 7664-93-9, and its EC number is 231-639-5. Its molecular formula is H₂SO₄ with a molecular weight of 98.08 g/mol.
What concentrations of Sulfuric Acid do you supply?
Common commercial strengths including 29%, 49%, 78%, 93% and 98%, across industrial, fertilizer, battery and laboratory-reagent grades. Tell us your process and we will confirm the right concentration and grade.
Do you supply Sulfuric Acid worldwide?
Yes. Chelora Chemicals supplies and exports Sulfuric Acid worldwide — across Asia Pacific, Europe, the Middle East, Africa and the Americas, as well as throughout India. Every consignment carries the COA with assay and trace-metal data, and the SDS.
How is Sulfuric Acid manufactured?
By the contact process: burning sulfur or roasting sulfide ores to sulfur dioxide, catalytically oxidising this to sulfur trioxide, and absorbing the trioxide into water or acid, then diluting to the target commercial strength.
What is Sulfuric Acid mainly used for?
Mainly fertilizer production (reacting phosphate rock to produce phosphoric acid), with major additional use in metal pickling, lead-acid batteries, petroleum refining and general chemical synthesis.
Is Sulfuric Acid hazardous?
Yes, it is a strong corrosive that causes severe skin burns and eye damage on contact, and reacts violently and exothermically with water. Hazard severity scales with concentration. Standard corrosive-liquid precautions and PPE apply.
What are the UN number and transport class?
UN 1830 for concentrated grades (>51%), Class 8, Packing Group II. Dilute grades may carry a different UN entry. ADR, IMDG, IATA and DOT rules apply to packing, labelling and routing.
How should Sulfuric Acid be stored?
In acid-resistant containers (typically HDPE, PP, or lead-lined steel for concentrated grades) at ambient temperature, away from incompatible materials such as most metals, organics and strong bases.
Why do you always add acid to water, not water to acid?
Diluting concentrated sulfuric acid is strongly exothermic. Adding water to concentrated acid can cause localised boiling and violent spattering; adding acid slowly to water dissipates the heat safely.
What purity grades do you offer?
Industrial, fertilizer, battery and laboratory-reagent grades, each with its own trace-metal (iron, chloride) specification and colour requirement reported on the COA.
What packing sizes and order quantities are available?
HDPE carboys and drums (25–250 kg), IBC totes, and bulk road tanker or ISO tank container shipments for larger volumes. Orders run from drum trial quantities up to bulk tanker loads.
Ready to source Sulfuric Acid?
Send us your concentration requirement and annual volume. You will get a price, a realistic lead time and a sample COA from someone who understands what the material has to do in your process — delivered anywhere in the world.