Calcium Hypochlorite 70% | Loc Thien Nationwide

In the Vietnamese water treatment and industrial sanitation industry, Calcium hypochlorite 70% — commercially known as chlorine or calcium chloride — is one of the most important disinfectants. Unlike liquid bleach (sodium hypochlorite NaOCl at a concentration of 5–15%), Ca(OCl)2 exists in powder or solid tablet form with an active chlorine content of up to 65–70%, allowing for more efficient transport, storage, and dosing in large-scale applications.

Urban water treatment plants, rural water supply stations, industrial wastewater treatment plants, fish and shrimp farms, and commercial swimming pools all use Ca(OCl)2 as the primary chlorine source in their disinfection processes. For each wholesale purchase, the technical manager needs to be familiar with the technical specifications, storage conditions, and dosage to ensure treatment effectiveness and workplace safety.

This article provides comprehensive technical information on 70% calcium hypochlorite—from its chemical properties, specifications, industry applications, safe usage guidelines, to storage and transportation regulations—to meet the needs of B2B customers for information and ordering.

What is Calcium Hypochlorite?

Calcium hypochlorite (Ca(OCl)2) is the calcium salt of hypochlorous acid (HClO), belonging to the group of inorganic chlorine compounds with strong oxidizing properties. Under normal conditions, it exists as a white powder or white to light gray granules, is soluble in water, and releases free chlorine (Cl2) through hydrolysis. This is the main mechanism that produces the product's bactericidal effect.

Chemically, Ca(OCl)2 is a strong oxidizing and corrosive substance. When exposed to moisture, acids, or organic matter, it decomposes rapidly and releases chlorine—this is both its mechanism of action as a disinfectant and a potential hazard that needs to be controlled during use and storage. Understanding this property helps engineers and technicians select the correct preparation procedures and wear appropriate protective equipment.

Other names and chemical formulas

In the Vietnamese market, calcium hypochlorite is known by various names depending on the industry and supplier: Chlorine, calcium chloride, chlorine powder, 70% chlorine, Ca(OCl)2In international technical documents, this product has the IUPAC name calcium bis(hypochlorite), and the CAS number is 7778-54-3, UN number is UN2880 (calcium hypochlorite, hydrated) or UN1748 (calcium hypochlorite, dry). The most common commercial active chlorine content is 65% and 70%, with the 70% type being more widely used in industrial applications in Vietnam.

When handling import procedures or checking Certificates of Origin (CO/CQ), the common English names are "Calcium Hypochlorite 70%" or "Chlorine (Calcium Hypochlorite) 65/70%". Purchasing staff need to compare the CAS number and chemical name on the documents to avoid confusion with other chlorine compounds such as TCCA (trichloroisocyanuric acid) or NaOCl (liquid bleach).

Product identifying characteristics

Commercial calcium hypochlorite is typically white to light gray in color, with a characteristic (pungent) chlorine odor. High-quality products are uniformly white, free from large clumps, and do not show any yellowing—a sign of moisture or degradation during transport and storage. When inspecting incoming shipments, visually inspect the container, check the temperature (moist Ca(OCl)2 may release heat), and take samples for testing the active chlorine content according to the provided Certificate of Analysis (COA).

Standard-packaged products typically come in sealed HDPE plastic containers or drums, with labels containing complete information about the manufacturer, composition, batch number, production date, expiration date, and safety warnings. For goods imported from China, a Certificate of Origin (CO) and Certificate of Quality (CQ) are required, along with a Certificate of Analysis (COA) for each batch.

Distinguish it from Sodium Hypochlorite (liquid bleach).

A common point of confusion in practice is the difference between Ca(OCl)2 and NaOCl (liquid bleach). Both belong to the group of chlorine-based disinfectants, but have distinctly different natures and applications. Ca(OCl)2 is solid, active chlorine content 65-70%It is more stable during storage, easier to transport over long distances, and suitable for applications requiring precise dosage control. Meanwhile, NaOCl is liquidTypically containing 5–15% active chlorine, it is unstable to heat and light and decomposes more rapidly.

When replacement is necessary, conversion must be based on the actual active chlorine content of each product—it cannot be exchanged 1:1 by weight. For example, 1 kg of 70% Ca(OCl)2 is equivalent to approximately 4,7 liters of 15% NaOCl in terms of active chlorine content. Correctly distinguishing between these two products is especially important when preparing technical documentation and calculating dosages in water treatment processes. See also the article. Javel Sodium Hypochlorite For a detailed comparison.

Specifications Ca(OCl)2 65%/70%

The technical specifications below are compiled from common commercial technical documents in the Vietnamese market. Actual values ​​may vary depending on the manufacturer and batch — always request a Certificate of Analysis (COA) for the specific batch when placing wholesale orders.

Appearance, content, moisture content, specifications

The most important thing when receiving Ca(OCl)2 is to check the actual active chlorine content according to the batch's Certificate of Analysis (COA), not just rely on the label. The content can vary from 65% to 70% depending on the manufacturer; some substandard batches may have content below 60%—directly affecting treatment efficiency and dosage calculations. Moisture content is also a crucial indicator: goods with moisture above 4% will experience rapid reduction in active chlorine content, generate heat in the warehouse, and increase the risk of fire and explosion.

The most common commercial standard packaging is 40–50 kg per sealed HDPE plastic drum. For large projects ordering by the container, it's necessary to agree on the packaging specifications beforehand to optimize shipping costs and reduce the risk of goods becoming damp during long-term storage.

CAS, MSDS, CO/CQ need to be checked.

For B2B clients—especially water supply project contractors, wastewater treatment plants, and seafood export businesses—complete technical documentation is a mandatory requirement for acceptance testing and internal audits. The minimum three documents that should be requested from a supplier are: MSDS (Material Safety Data Sheet / SDS according to GHS), WITH THE (Certificate of Analysis for each shipment), and CO/CQ (Certificate of origin and quality from the Chinese manufacturer). CAS number 7778-54-3 and UN number 2880/1748 are mandatory information on labels and shipping documents.

If the project requires a VAT invoice based on the actual shipment value, this should be discussed with the supplier at the quotation stage—not after receiving the goods. Loc Thien issues VAT invoices and provides complete MSDS, COA, and CO/CQ documents as required for each order.

Quality standards and considerations when choosing products.

In Vietnam, calcium hypochlorite used for domestic water treatment must meet the requirements of QCVN 01:2009/BYT (drinking water quality standard) and the guidelines of the Department of Environmental Health Management on disinfectant chemicals. Buyers should request that suppliers provide additional third-party test results (if available) and specific manufacturer information to compare with the list of authorized suppliers.

A practical note: Ca(OCl)2 decomposes gradually over time, especially when exposed to light, moisture, and heat. Products stored for more than 6 months from the date of manufacture need to have their active chlorine content re-checked before use in a project. Ordering only what is needed and avoiding excessive inventory is the best way to ensure quality.

What is calcium hypochlorite used for?

Thanks to its high active chlorine content and easily transportable solid form, Ca(OCl)2 is widely used in many industrial fields in Vietnam. The product's bactericidal effect comes from an oxidation mechanism: when dissolved in water, Ca(OCl)2 produces hypochlorous acid (HClO) — a free chlorine form capable of disrupting cell membranes and inactivating microbial enzymes.

Applications range from large-scale municipal water treatment to industrial sanitation and aquaculture. Each field has its own requirements regarding dosage, mixing procedures, and chlorine residue control—demanding technicians to have a thorough understanding of the characteristics of each application. See more in the catalog. water treatment chemicals Visit Loc Thien's website for a complete list of related products.

Treatment of domestic water, wastewater, and water supply.

This is the most traditional and common application of Ca(OCl)2 in Vietnam. Rural water supply stations, urban water treatment plants, and industrial wastewater treatment systems all use calcium hypochlorite as the primary chlorine source in the final disinfection step. Loc Thien has been supplying Ca(OCl)2 to many water treatment plants and industrial water supply systems in Southern Vietnam for over 10 years, accumulating practical experience in advising on dosage, storage procedures, and troubleshooting.

The chlorination dosage in typical domestic water treatment ranges from 0,5–2,0 mg/L of free residual chlorine (according to WHO guidelines and QCVN 01:2009/BYT), however, the actual dosing dose depends on the quality of the influent water source—especially the concentration of organic matter, turbidity, and pH. Operating engineers need to measure residual chlorine regularly to adjust the dosing dose accordingly.

Disinfecting fish ponds, livestock pens, and storage tanks.

In aquaculture—especially industrial shrimp farming—Ca(OCl)2 is used to treat ponds before the farming season, kill pathogens in pond water, and disinfect equipment and tanks. The dosage used for pond treatment is usually much higher than for treating drinking water, ranging from 10 to 30 kg/1.000 m3 of water depending on the level of pollution and the purpose of treatment. After treatment with chlorine, sufficient time must be allowed for the chlorine to decompose (usually 7–10 days depending on conditions) before stocking. See also the catalog. chemicals for the aquaculture industry For further information on suitable products for each stage of farming, please refer to the following.

In the livestock and poultry industry, diluted Ca(OCl)2 is used for routine cleaning and disinfection of barns and for disease prevention. The diluted Ca(OCl)2 solution is also used to disinfect vehicles entering the farm and farm pathways as part of a strict biosecurity process.

Paper bleaching, textiles, and industrial cleaning.

The paper and textile dyeing industries use Ca(OCl)2 as a bleaching agent. Its high active chlorine content oxidizes color bonds in pulp, fibers, and textile materials, creating a stable white color. In the food and beverage industry, solutions of Ca(OCl)2 are used for cleaning and disinfecting equipment surfaces, pipelines, and production areas according to HACCP standards.

For surface cleaning applications in food processing plants, the concentration of the solution used is typically lower (50–200 ppm active chlorine) and requires strict residue control. Refer to the equipment manufacturer's MSDS and operating instructions to ensure no corrosion of contact surfaces. See more. hóa chất vệ sinh công nghiệp To find suitable products.

How to use Calcium Hypochlorite safely

Ca(OCl)2 is a strong oxidizing chemical, classified as hazardous under the GHS system. Users—from technical workers to operating engineers—must adhere strictly to mixing procedures, dosages, and wear appropriate protective equipment to ensure absolute safety during work. All personnel in direct contact with the product must receive chemical safety training and be capable of handling basic emergency situations.

The most important principle when using Ca(OCl)2: Always add chemicals to water, never add water to chemicals.A reverse reaction can cause chemical splashing, rapid release of chlorine gas, and a local fire or explosion risk within the mixing tank. Use clean, cold water for dilution and avoid mixing in direct sunlight or in enclosed, poorly ventilated spaces.

Principles of dilution and chemical dosing.

When preparing a stock solution for dosing, Ca(OCl)2 is usually diluted to a 1–5% active chlorine solution first, then added to the system according to the calculated dosage. Avoid diluting it more concentrated than 5–10% as this reduces solubility and increases the risk of calcium precipitation in the pipeline. Use HDPE or FRP mixing tanks—do not use metal tanks as Ca(OCl)2 is highly corrosive to common metals.

The dosing pump and chemical mixing tank should be thoroughly cleaned after each shift to prevent the accumulation of Ca(OH)2 and CaCO3 deposits in the valves and pump heads. Periodically check the residual chlorine concentration in the treated water using a test kit or chlorine meter to adjust the dosing dose accordingly.

Recommended dosage based on application.

The dosage of Ca(OCl)2 depends on several factors: the volume to be treated, the quality of the water source (pH, turbidity, chlorine requirements), the desired residual chlorine target, and the contact time. The table below is a practical reference for common applications, using 70% Ca(OCl)2:

• Water treatment for domestic use (disinfection): 0,5–2,0 mg/L free residual chlorine (add based on residual chlorine measurement results 30 minutes after the dosing point)
• Renovating shrimp/fish ponds: 10–30 kg of Ca(OCl)2 70% per 1.000 m3, depending on the level of pollution.
• Disinfecting water tanks: Prepare a solution of 50–200 ppm, spray evenly over the tank surface, leave for 30 minutes, then rinse thoroughly.
• Clean the surfaces of food processing equipment: 50–200 ppm active chlorine in the final cleaning solution
• Disinfecting equipment and vehicles entering the livestock farm: Prepare a solution of 500–1.000 ppm for spraying or dipping.

These dosages are for reference only. Operating engineers need to adjust them according to the characteristics of the water source and the specific requirements of each system. Further consultation with the equipment manufacturer's documentation and internal quality control procedures is recommended before implementation.

Protective equipment and hazardous reaction prevention

When working with Ca(OCl)2, the minimum personal protective equipment (PPE) required includes: safety glasses (Avoid shooting into the eyes) activated carbon face mask or chlorine mask, chemical-resistant rubber gloves, plastic apron and bootsWork in a well-ventilated space; if working in an enclosed warehouse, use forced ventilation to remove chlorine fumes.

Absolutely avoid allowing Ca(OCl)2 to come into contact with: acid (including vinegar and lemon juice — the reaction releases chlorine gas immediately). ammonia and nitrogen compounds (creates toxic chloramine) flammable organic matter (causing spontaneous combustion), and oils and fats, gasolineIn case of large spills: use dry soil or sand to absorb the spillage, collect it in a sealed container, and contact a hazardous waste disposal unit. Do not use excessive water to rinse the area as this may cause the chemical to spread further.

Storage and transportation of Calcium Hypochlorite

Calcium hypochlorite belongs to the GHS system of hazardous oxidizing chemicals — classified as Class 5.1 (oxidizing agent) in the transport of dangerous goods by road and sea. Proper storage and transportation are not only legal requirements but also directly affect product quality upon delivery to the customer.

Practical experience from Loc Thien shows that most quality issues—lower product content, heat buildup in warehouses, bulging bags—stem from improper storage at intermediate distributors or during on-site inventory. Understanding the following storage principles will help the operations team prevent risks early on.

Store in a dry, cool place, away from moisture.

Ca(OCl)2 must be stored in a dry, cool, and well-ventilated warehouse at a temperature not exceeding 35°C, away from direct sunlight and heat sources. The optimal warehouse humidity should be below 60% — a humid environment causes the product to absorb moisture, gradually decompose, and continuously release chlorine gas, leading to the accumulation of toxic gases in the warehouse. Unopened containers must remain sealed; opened containers must be tightly closed immediately after use and used within the shortest possible time.

Do not load Ca(OCl)2 directly onto damp cement floors — use dry plastic or wooden pallets, at least 10 cm above the floor. Do not stack containers too high (maximum 3–4 layers) to avoid deformation and the risk of tipping over. Always check the surface temperature of the containers periodically — unusually hot containers are a sign that they need to be isolated and inspected immediately.

Separate from acids, organic substances, and reducing agents.

In chemical storage facilities, Ca(OCl)2 must be completely separated and partitioned from other chemical groups: acids (HCl, H2SO4, HNO3, acetic acid, etc.), reducing agents (Na2SO3, FeSO4, etc.), ammonia and ammonium salts, flammable organic substances (alcohol, solvents, oils), and other oxidizing agents (potassium permanganate, hydrogen peroxide). The reaction between Ca(OCl)2 and acids is strong, releasing large amounts of chlorine gas—this is the cause of many accidents at chemical storage facilities and construction sites in Vietnam.

Storage facilities for Ca(OCl)2 must be equipped with CO2 or dry powder fire extinguishers (water extinguishers are not permitted), hazardous chemical warning signs in accordance with TCVN 6406:2017, and a clear evacuation plan. Warehouse management personnel must be trained in responding to hazardous chemical spills.

Packaging and nationwide shipping options

70% Ca(OCl)2 is packaged in 40-50 kg HDPE plastic drums, stacked on pallets, and can be transported in specialized Class 5.1 hazardous goods trucks. For long-distance transport, it must be protected from rain and the temperature inside the vehicle must not exceed 40°C. Drivers and assistants must be briefed on the hazardous nature of the goods and basic emergency procedures.

Loc Thien delivers Ca(OCl)2 nationwide using specialized trucks, ensuring that goods arrive in their original packaging, meet specifications, and have all the necessary hazardous goods transportation documentation as required by Decree 42/2020/ND-CP. For large project orders, Loc Thien collaborates to develop a delivery plan that aligns with the construction schedule and warehouse conditions of the partner. See more PAC water treatment , and TCCA 90% — Water treatment chemical products are often packaged with Ca(OCl)2.

Where to buy Calcium Hypochlorite? — Loc Thien

For projects or ongoing production requiring wholesale calcium hypochlorite 70%, choosing a reliable supplier is just as important as product quality. Delayed deliveries, substandard product content, lack of technical documentation, or absence of VAT invoices are all real risks that B2B buyers often encounter when working with unprofessional distributors.

Benefits of buying wholesale at Loc Thien

Loc Thien Co., Ltd. specializes in distributing industrial chemicals—including Ca(OCl)2 calcium hypochlorite—to water treatment plants, wastewater treatment plants, shrimp farms, food processing plants, and project contractors in Southern Vietnam for over 10 years. With experience supplying numerous water supply and commercial swimming pool projects, Loc Thien understands the technical requirements, timelines, and documentation of each project type.

B2B customers purchasing from Loc Thien enjoy: competitive wholesale prices based on volume, goods with complete CO/CQ/MSDS/COA certificates, VAT invoices for each shipment, free technical consultation from an experienced team, and support in preparing product documentation as required by the investor or regulatory agency.

VAT invoice, Certificate of Origin/Quality, technical consultation.

Loc Thien issues VAT invoices for each shipment, providing complete Certificates of Origin (CO) and Certificates of Quality (CQ) from the manufacturer, along with MSDS and COA for the specific batch. For state-managed water treatment projects or projects requiring chemical acceptance testing, Loc Thien assists in preparing complete technical documentation as required by the investor and inspection agency.

Loc Thien's technical team is ready to advise on dosage, mixing procedures, storage conditions, and product selection tailored to the specific needs of each customer's system—not just selling products. This is what sets us apart from purely commercial distributors who lack specialized chemical engineering expertise.