The most expensive mistake in a disinfection or bleaching tender is assuming that "bleach is a cheap chemical." Two jerrycans both labelled bleach do more than twice as different a job when one holds 5% and the other 12-15% active chlorine, and, worse, a poorly stored product loses its strength while it is still sitting in the warehouse. Worked with the right concentration and the right handling, sodium hypochlorite (bleach) is the cheapest and most effective oxidizing disinfectant in industry. This guide covers the active chlorine grades of this product (CAS 7681-52-9), its sector-by-sector uses, its safety rules and the bulk supply process, all from a B2B buyer's point of view.
What Is Sodium Hypochlorite (Bleach)?
Sodium hypochlorite (bleach) is a greenish-yellow liquid with a characteristic sharp odour, produced by passing chlorine gas in a controlled way through a solution of sodium hydroxide (caustic soda). Its chemical formula is NaOCl and its CAS number is 7681-52-9. Because the pure solid form is practically unstable, the commercial product is always manufactured and sold as an aqueous solution.
The strength of the solution is expressed not by the weight percentage of the substance itself but by the amount of active chlorine it contains. Active chlorine is the measure of hypochlorite's oxidizing and germ-killing capacity; on labels it appears as "5% active chlorine" or "150 g/L active chlorine."
| Property | Value / Note |
|---|---|
| Chemical name | Sodium hypochlorite |
| Common names | Bleach, hypochlorite, NaOCl solution |
| CAS number | 7681-52-9 |
| EC number | 231-668-3 |
| Molecular formula | NaOCl |
| Molecular weight | 74.44 g/mol |
| Appearance | Greenish-yellow, clear liquid |
| Odour | Sharp, characteristic chlorine smell |
| pH (solution) | 11-13 (strongly alkaline) |
| Commercial grades | 5%, 10%, 12-15% active chlorine |
| GHS pictograms | GHS05 (corrosive), GHS09 (environment) |
| ADR class | 8 (corrosive substance) |
The solution is strongly alkaline; this high pH both extends the product's shelf life and creates a corrosion risk on some surfaces (aluminium, painted metal). Sodium hypochlorite works on its own as a disinfectant, a bleaching agent and an oxidizer all at once — and this triple functionality is the real reason it is so widely used.
What Is Active Chlorine? The 5%, 10% and 12-15% Grades
When buying sodium hypochlorite, the single most important parameter to check is the active chlorine percentage. When comparing prices, the figure that matters is not the price per litre but the cost per unit of active chlorine; otherwise a low-concentration product that looks cheap actually does the job at a higher real cost.
Active chlorine is the effective component that determines the solution's germ-killing and bleaching power. In practice, dosing is always calculated against an active chlorine target: a facility that wants to disinfect a surface with 1000 ppm free chlorine, for example, uses roughly three times the volume of a 5% product compared with a 12-15% one.
| Active chlorine | Typical use area | Notes |
|---|---|---|
| 5% | Household cleaning, light surface hygiene, small-scale disinfection | Low concentration, better stability; expensive per unit of active chlorine |
| 10% | Industrial surface cleaning, general disinfection, non-food hygiene | Most common industrial pull; the balance point |
| 12-15% | Drinking/waste water chlorination, pools, textile and paper bleaching, dosing-pump processes | Most economical per unit of active chlorine; decomposes faster, needs careful handling |
Practical rule: businesses with low consumption and limited handling capability should start with 5-10%. In facilities with a dosing pump, a closed transfer line and steady offtake, 12-15% carries more active chlorine per shipment and noticeably lowers total cost. But do not forget that the higher-concentration product decomposes faster; stock should be planned according to consumption speed.
How Is It Produced and Why Does It Degrade Over Time?
Commercial sodium hypochlorite is obtained from the reaction of chlorine gas with a chilled sodium hydroxide (caustic soda) solution:
Cl2 + 2 NaOH → NaOCl + NaCl + H2O
This reaction produces salt (NaCl) alongside the hypochlorite; in commercial products a certain excess of free caustic (NaOH) is deliberately left in, because a high pH slows the product's decomposition.
Sodium hypochlorite is thermodynamically unstable; even under the best conditions it slowly loses its active chlorine. Decomposition proceeds along two main paths:
- Active chlorine loss (strength drop): over time NaOCl converts to chlorate and salt, losing its disinfection power. This is also known as the product "tiring."
- Oxygen release: especially in the presence of metal-ion (iron, copper, nickel) contamination and light, hypochlorite decomposes by releasing oxygen; this can build up pressure in closed containers.
The main factors that accelerate decomposition are temperature, light, metal impurity and falling pH. As a general approach, the rate of decomposition roughly multiplies for every 10 °C rise in temperature; this is why product left in a hot warehouse over the summer can drop below its label value within a few weeks. This is exactly why sodium hypochlorite is a chemical to be consumed, not stockpiled: FIFO (first in, first out) rotation and regular active chlorine determination (titration) are an inseparable part of purchasing discipline. A batch-based COA (certificate of analysis) is the only way to verify the real active chlorine value at the moment of delivery.
Sodium Hypochlorite in Disinfection and Hygiene
Sodium hypochlorite's best-known function is as a broad-spectrum disinfectant. It is effective against bacteria, viruses, yeasts, moulds and spores; that is why it is the backbone of both domestic and industrial hygiene.
Its mechanism is simple: hypochlorite oxidizes the cell membrane and proteins of microorganisms, breaking down their structure. Effectiveness depends largely on free chlorine concentration, contact time and pH.
Typical application concentrations (on an active chlorine basis):
- General surface disinfection: 200-1000 ppm free chlorine
- Non-food high-risk area (toilets, waste areas): 1000-5000 ppm
- Post-outbreak / heavy contamination: 5000-10000 ppm
Critical field detail: hypochlorite reacts quickly with organic soil (grease, protein, dirt) and is consumed. For this reason the surface must always be pre-cleaned before disinfection; hypochlorite applied directly to a dirty surface spends its real free chlorine before it even reaches the target. The "clean first, then disinfect" rule is the step most often skipped in the field, yet it is the one that makes the biggest difference.
Surface and Industrial Cleaning
Alongside disinfection, sodium hypochlorite features in industrial cleaning formulations as a powerful stain remover and odour neutralizer. Thanks to its oxidizing character, it breaks down and lifts organic stains, mould marks and coloured soils from the surface.
Chlorine-based cleaning products are not hypochlorite alone; they are usually part of a formulation. To boost effectiveness and ease of use, hypochlorite works together with auxiliary raw materials:
- Caustic soda (NaOH): increases grease-cutting power and alkalinity, stabilizes the product
- Surfactants: provide wetting, foam and soil-removal performance
- Chelating agents: bind metal ions, improving both stability and hard-water performance
Choosing a chlorine-compatible (chlorine-resistant) surfactant is critical in these formulations; a poorly chosen surface-active agent is oxidized by the hypochlorite, consuming both itself and the product's active chlorine. You can review our what are surfactants article for surfactant chemistry and chlorine compatibility. For the general formulation logic and raw-material selection of chlorine-based products, our cleaning and detergent chemicals guide is a comprehensive starting point.
In industrial cleaning, hypochlorite is at its strongest in food-processing plants (CIP-line disinfection), cold storage, waste-collection areas, sewers and any space with an odour problem.
Sodium Hypochlorite in Water and Pool Treatment
One of the highest-tonnage uses of sodium hypochlorite is water treatment. In the chlorination of drinking water, process water, wastewater and swimming pools, it is fed into the system with dosing pumps.
When added to water, hypochlorite converts into an equilibrium of hypochlorous acid (HOCl) and hypochlorite ion (OCl⁻), which is what provides disinfection. The ratio of this equilibrium is set by the water's pH:
- Low pH (6.5-7.5): most of the equilibrium is HOCl; disinfection is far more effective
- High pH (8+): OCl⁻ dominates; disinfection power drops noticeably
This is why in pool and water operations, pH control is as important as the chlorine dose. At high pH, no matter how much chlorine is added, real disinfection stays weak; to avoid wasting chlorine, pH is generally held in the 7.2-7.6 band.
For water treatment applications the choice is almost always the 12-15% grade with a dosing pump and a closed transfer system. High concentration means fewer shipments and less storage volume for the same treatment capacity; however, product freshness must be tracked meticulously, because degraded hypochlorite throws off the dosing calculation and leads to chlorate build-up.
Use in Textile and Paper Bleaching
Sodium hypochlorite is a traditional bleaching (kier) chemical. It is used to whiten cotton and cellulose-based fibres, to brighten paper pulp and for colour removal in some recycling processes.
Chlorine-based bleaching is powerful and economical; however, as environmental regulations have tightened, many textile and paper plants have moved to oxygen-based alternatives such as hydrogen peroxide, which produce no chlorinated by-products (AOX). Even so, hypochlorite remains indispensable in certain colour-removal and spot-bleaching applications.
| Bleaching method | Active substance | Standout feature |
|---|---|---|
| Chlorine-based bleaching | Sodium hypochlorite | Powerful, economical; AOX / chlorinated by-product risk |
| Oxygen-based bleaching | Hydrogen peroxide | Environmentally friendly; residue is water and oxygen |
| Combined sequence | Hypochlorite + peroxide | Two-stage whiteness for tough stains |
In textiles, hypochlorite bleaching must always be followed by an antichlor (neutralization) step; otherwise chlorine left in the fibre causes loss of strength and yellowing over time. This sensitivity also explains why hypochlorite must be dosed carefully in textiles.
Safety: Do Not Mix With Acids (Chlorine Gas Risk)
Used safely, sodium hypochlorite is a trouble-free product; but in the field a single mistake can be fatal. The most critical rule is clear:
Sodium hypochlorite must never be mixed with products containing acid.
When hypochlorite contacts acidic products such as hydrochloric acid (spirit of salt), lime/scale removers or some toilet cleaners, toxic chlorine gas (Cl2) is released:
NaOCl + 2 HCl → Cl2↑ + NaCl + H2O
Chlorine gas is visible, sharp-smelling and, when inhaled, causes serious damage to the respiratory tract, pulmonary oedema and a risk of death in enclosed spaces. Unfortunately, this accident is one of the most common industrial incidents, happening to cleaning staff who combine two products in the same bucket "so it cleans better." Hypochlorite must also never be mixed with products containing ammonia; this time toxic chloramine gases form.
Other essential safety measures:
- PPE: chemical goggles/face shield, nitrile or PVC gloves, apron. Respiratory protection at high concentration.
- Skin and eyes: because it is strongly alkaline, it irritates skin and causes serious eye damage; on contact, rinse with plenty of water for at least 15 minutes.
- Ventilation: always ensure ventilation when used in enclosed spaces; leave the area if chlorine odour is detected.
- Material compatibility: it corrodes aluminium, painted metal and some gaskets; pumps and lines must be chlorine-resistant (PVC, PP, PVDF).
Stability and Decomposition: Cool, Dark, HDPE, Vented
Under the right conditions sodium hypochlorite keeps its usable active chlorine for several months; under the wrong conditions it drops below its label value within weeks. The essentials of storage are:
- Cool environment: ideal storage is in the 15-25 °C band. Temperature is enemy number one of active chlorine loss; a hot warehouse tires the product before it is even sold.
- Protection from light: UV light accelerates decomposition; packaging is produced opaque and the warehouse must not receive direct sun.
- Compatible packaging (HDPE): standard packaging is HDPE jerrycan, drum and IBC. Metal containers (especially iron/steel) both corrode and catalyze decomposition by releasing metal ions.
- Ventilation: because the product slowly releases oxygen as it decomposes, packaging is closed with vented caps; pressure can build up in blind-plugged, fully sealed closed containers.
- Prevent metal and dirt contact: even trace amounts of iron, copper and nickel seriously accelerate decomposition; transfer equipment must be clean and chlorine-compatible.
- FIFO and titration: stock is rotated on a first-in-first-out basis; active chlorine in a long-standing batch is verified by titration.
We covered general warehouse layout, segregated-storage principles and spill response in detail in our chemical storage and ADR transport guide; for hypochlorite specifically, the most critical point is to store the product physically separate from acids and ammonia.
Packaging and Transport: Jerrycan, Drum, IBC and ADR
By road, sodium hypochlorite is transported under ADR Class 8 (corrosive substances), typically as UN 1791 (hypochlorite solution). This means shipment must be made with correctly labelled, UN-approved packaging and with vehicles that comply with ADR requirements. For export shipments, the same logic applies under IMDG (sea) or ADR/RID rules across Europe, so international buyers should confirm the UN packaging and documentation up front.
Packaging is chosen according to consumption volume and the facility's handling capability:
| Packaging | Volume | Suitable use |
|---|---|---|
| Jerrycan | 20-30 L | Low consumption, point use, hygiene teams |
| Drum | 200-220 L | Medium-scale consumption, manual transfer |
| IBC | 1000 L | High consumption, dosing-pump systems, water/textile plants |
Packaging must always be vented HDPE; temperature and light exposure should be limited during transport. Because freshness is more critical in high-concentration (12-15%) products, short and regular delivery lead times are especially important for these grades — a key point for export routes where transit time is longer.
Supply, Price and Ordering: The Yüksek Kimya Difference
The price of sodium hypochlorite varies with active chlorine concentration, order tonnage, packaging type and delivery frequency. But for this product the real criterion that defines the right supplier is not price but freshness and continuity: a degraded product is the most expensive solution even at the cheapest price.
Clarifying the following information when requesting a quote speeds up the process:
- Active chlorine concentration: 5%, 10% or 12-15%? The effectiveness level suited to your application
- Monthly consumption: steady offtake is the single most decisive item for both price and delivery planning
- Packaging preference: jerrycan, drum or IBC — according to your facility's forklift, pump and storage capability
- Delivery point and frequency: a shipment plan matched to your consumption speed so the product is used fresh
- Documentation needs: MSDS and batch-based COA (especially in water and non-food hygiene applications)
For everything to look at when evaluating a supplier, you can review our chemical supplier selection guide.
From our facility in Kestel, Bursa, with shipment across Turkey and to export markets, we offer options suited to your needs:
- Concentration options: 5%, 10% and 12-15% active chlorine
- Packaging: vented HDPE jerrycan, drum and IBC (1000 L)
- Documentation: MSDS and COA shared with every batch; operation certified to ISO 9001, ISO 14001, ISO 45001 and GHP
- Logistics: ADR-compliant, planned and regular shipment; delivery-time discipline that ensures the product arrives fresh
- Technical support: field experience in concentration selection, dosing, storage layout and formulation compatibility
Alongside sodium hypochlorite, you can meet your cleaning/disinfection recipe's caustic, surfactant and auxiliary raw-material needs from a single source; for the full product range see our industrial chemicals and additives category.
To request a quote: reach us through our contact page or call directly; we will send a price tailored to your tonnage, concentration and delivery point the same day.
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Frequently Asked Questions
What is sodium hypochlorite (bleach) and what is its CAS number?
Sodium hypochlorite is a greenish-yellow, sharp-smelling liquid produced by passing chlorine gas through a sodium hydroxide solution. Its chemical formula is NaOCl and its CAS number is 7681-52-9. The dilute aqueous solution is commonly known as bleach; in industry its strength is expressed as a percentage of active chlorine (5%, 10%, 12-15%).
What is the difference between 5%, 10% and 12-15% active chlorine?
All three are aqueous solutions of the same substance; the difference is the amount of active chlorine per litre and the disinfection or bleaching power that follows. 5% suits domestic and light hygiene use, 10% covers industrial cleaning and general disinfection, and 12-15% is preferred for water treatment, textile bleaching and high-tonnage dosing-pump processes. Higher concentration is more economical per unit of active chlorine but decomposes faster and demands more careful handling.
Why must sodium hypochlorite never be mixed with acids?
When sodium hypochlorite contacts an acidic product (hydrochloric acid, descaler, toilet cleaner) it releases toxic chlorine gas. This gas causes serious damage to the respiratory tract and is life-threatening in enclosed spaces. Hypochlorite must never be used at the same time as acid-based cleaners or poured into the same container.
Where can sodium hypochlorite be sourced in bulk?
Yüksek Kimya, a B2B chemical distributor based in Kestel, Bursa, ships sodium hypochlorite at 5%, 10% and 12-15% active chlorine in jerrycan, drum and IBC formats. Every batch includes MSDS and COA, ADR-compliant transport and fast quotations by phone or e-mail for domestic and export buyers.