sodium hydroxide

sodium hydroxide
Ben Mills · Public domain · source
Name	Sodium hydroxide
IUPAC name	Sodium hydroxide
Other names	Caustic soda, lye
Chemical formula	NaOH
Molar mass	39.997 g·mol−1
Appearance	White crystalline solid
Density	2.13 g·cm−3 (solid)
Melting point	318 °C
Boiling point	1,388 °C
Solubility	Miscible in water

sodium hydroxide Sodium hydroxide is an inorganic ionic compound widely used in industrial and laboratory contexts. It is a strong base and a common reagent in chemical synthesis, manufacturing, and processing. Major producers and users include multinational corporations, regional manufacturers, and national utilities.

Description and Properties

Sodium hydroxide is a white crystalline solid with a high ionic lattice energy and strong basicity comparable to alkali metal hydroxides used in industrial practice; its physical constants are catalogued by agencies such as International Union of Pure and Applied Chemistry, National Institute of Standards and Technology, and national metrology institutes. The compound dissolves exothermically in water, producing concentrated alkaline solutions used in processes overseen by entities like European Chemicals Agency, United States Environmental Protection Agency, and regulatory frameworks such as REACH. Solid NaOH is hygroscopic and deliquescent, properties considered in standards from International Organization for Standardization and testing by laboratories affiliated with American Chemical Society. Thermal decomposition and phase behavior are relevant to materials databases maintained by organizations such as Royal Society of Chemistry and industrial specifications issued by conglomerates like BASF and Dow Chemical Company.

Production and Manufacture

Commercial production is dominated by electrochemical routes historically developed through technologies associated with companies such as Solvay S.A., Hercules Inc., and innovations from research institutions including Massachusetts Institute of Technology and University of Cambridge. The chloralkali process—using diaphragm, membrane, or mercury cell technologies—electrolyzes brine to yield sodium hydroxide, chlorine, and hydrogen; membrane cells were advanced in collaborations involving Siemens and chemical engineering groups at Imperial College London. Industrial-scale plants are operated by multinational firms like Olin Corporation and regional utilities under energy policies influenced by bodies such as International Energy Agency and national grids like National Grid (Great Britain). Byproduct management and process integration with chlorine manufacture are subjects of case studies by United Nations Environment Programme and trade bodies including European Chlorinated Solvents Association.

Chemical Reactions and Uses

NaOH participates in neutralization reactions central to procedures taught in courses at institutions such as University of California, Berkeley and used in synthesis reported in journals like Journal of the American Chemical Society. It saponifies triglycerides in processes traced to methods from Industrial Revolution-era soapmakers and modern firms such as Procter & Gamble. It is used in biodiesel transesterification methods developed in studies from National Renewable Energy Laboratory and in cellulose processing techniques applied by companies like International Paper and researchers at ETH Zurich. It serves as a reagent in organic transformations documented in volumes from Wiley-VCH and reactions catalogued in databases produced by Royal Society of Chemistry and ACS Publications. In analytical chemistry, NaOH titrations are standardized to procedures endorsed by American National Standards Institute and referenced in compendia such as USP (United States Pharmacopeia).

Applications by Industry

Chemical manufacturing firms including LyondellBasell, DuPont, and Shell plc incorporate NaOH in alkali-catalyzed syntheses and refinery operations. In pulp and paper production, companies like Stora Enso and UPM use NaOH in kraft pulping processes influenced by engineering research from KTH Royal Institute of Technology. Textile processing at manufacturers such as Arvind Limited and dyehouse operations tied to standards by ISO use caustic treatments. Water treatment utilities model coagulation and pH control employing NaOH under guidelines from World Health Organization and American Water Works Association. Food processing firms regulated by Food and Drug Administration apply controlled uses for peeling and pH adjustment in accordance with national food safety laws like the Food Safety Modernization Act. Petroleum and petrochemical refineries run by ExxonMobil and Chevron Corporation deploy NaOH in desulfurization and refining steps.

Health, Safety, and Environmental Impact

Exposure risks are managed under occupational safety frameworks from Occupational Safety and Health Administration and National Institute for Occupational Safety and Health guidelines; incidents and case law have been adjudicated in courts such as the United States Court of Appeals and regulatory enforcement actions by agencies like European Chemicals Agency. Sodium hydroxide is corrosive and can cause chemical burns, requiring medical protocols referenced by World Health Organization clinical guidance and emergency response resources from Red Cross. Environmental impacts of releases are assessed using criteria from United Nations Environment Programme and remediation standards applied by agencies such as Environment Agency (England and Wales). Worker training programs and hazard communication follow systems developed by International Labour Organization and labels aligned with Globally Harmonized System of Classification and Labelling of Chemicals.

Handling, Storage, and Disposal

Best practices for handling and storage are codified in safety data sheets prepared according to Occupational Safety and Health Administration and European Commission requirements and followed by industrial operators like BASF and municipal utilities such as Thames Water. Storage typically uses corrosion-resistant containers specified by standards from American Society for Testing and Materials and emergency planning coordinated with local authorities including Federal Emergency Management Agency. Disposal and waste treatment comply with regulations from Environmental Protection Agency and national statutes like Resource Conservation and Recovery Act, and often involve neutralization, recovery, or incineration pathways overseen by licensed firms and waste management authorities such as Veolia.

Category:Industrial chemicals