Sodium hypochlorite

Sodium hypochlorite is an inorganic chemical compound with the formula ClNaO and CAS number 7681-52-9. It is a powerful oxidizing agent and disinfectant commonly known as liquid bleach. With a molecular weight of 74.44 g/mol, this chlorine-based compound is classified as corrosive to skin and eyes, and poses environmental hazards to aquatic life. It is widely used for water treatment, sanitation, and bleaching applications across various industries.

Sodium hypochlorite is typically encountered as a pale yellow to greenish aqueous solution with a characteristic chlorine-like odor. It is highly soluble in water and decomposes readily when exposed to light, heat, or acidic conditions, releasing chlorine gas. The compound is unstable in concentrated form and is usually supplied as solutions ranging from 3-15% concentration. Its oxidizing nature makes it reactive with organic materials and reducing agents.

Sodium hypochlorite is primarily used as a disinfectant and bleaching agent across multiple industries. Major applications include water treatment for swimming pools and drinking water purification, surface disinfection in healthcare and food processing facilities, textile bleaching, and paper pulp processing. It is also used in wastewater treatment, cleaning product formulations, and as an antimicrobial agent in various industrial processes requiring sanitation and sterilization.

Sodium hypochlorite requires careful handling due to its corrosive properties and classification as Skin Corr. 1B and Eye Dam. 1. Essential personal protective equipment includes chemical-resistant gloves, safety goggles or face shield, and protective clothing. Work in well-ventilated areas to avoid inhaling vapors, and never mix with acids or ammonia-based products as this can generate toxic chlorine gas. Always add water to the chemical, not vice versa, to prevent violent reactions.

Sodium hypochlorite should be stored in a cool, dry, well-ventilated area away from direct sunlight and heat sources. Use original containers or compatible materials like polyethylene, avoiding metal containers which can catalyze decomposition. Keep strictly separated from acids, reducing agents, and organic materials to prevent dangerous reactions. Maintain storage temperatures below 25°C to minimize decomposition, and ensure containers are tightly sealed to prevent concentration changes and chlorine gas release.

Sodium hypochlorite contact requires immediate first aid due to its corrosive nature. For skin contact, immediately remove contaminated clothing and flush affected area with plenty of water for at least 15 minutes. For eye contact, rinse immediately with clean water for at least 15 minutes and seek medical attention. If inhaled, move to fresh air immediately. In case of ingestion, do not induce vomiting and seek immediate medical care. Always consult a physician after significant exposure.

Sodium hypochlorite disposal must comply with local and European waste regulations due to its hazardous classification and aquatic toxicity (Aquatic Acute 1; Aquatic Chronic 1). Small quantities can often be neutralized and diluted before disposal, but this should only be done by trained personnel following approved procedures. Larger quantities require disposal through licensed hazardous waste contractors. Never dispose of concentrated solutions directly into sewage systems or the environment without proper treatment and authorization.

Sodium hypochlorite is classified under ADR regulations as Class 8 (corrosive substances), Group II, requiring specific transport procedures. Packages must bear appropriate hazard labels including GHS05 and GHS09 pictograms with 'Danger' signal word. Use approved packaging suitable for corrosive liquids, ensure proper documentation including transport documents and safety data sheets. Vehicles must be equipped with appropriate emergency equipment, and drivers require ADR training for transporting corrosive materials.

Sodium hypochlorite is subject to various European regulations including REACH registration, CLP classification requirements, and biocide regulations when used for antimicrobial purposes. It is not currently listed as a Substance of Very High Concern (SVHC). The compound must be classified and labeled according to its hazard classes (Skin Corr. 1B, Eye Dam. 1, Aquatic Acute/Chronic 1). Users must ensure compliance with workplace safety regulations and environmental discharge limits due to its aquatic toxicity.

Sodium hypochlorite is available throughout Europe from specialized chemical distributors like OYSI, which supplies high-quality chemical products to industrial and professional customers. When purchasing, ensure suppliers provide proper documentation including safety data sheets, certificates of analysis, and regulatory compliance information. Choose reputable distributors who understand the handling, storage, and transport requirements for this corrosive substance and can provide technical support for safe usage in your specific applications.