CEH Report

Table of Contents

Abstract

Sodium, calcium, potassium and lithium hypochlorite are strong oxidizing agents used for bleaching, sanitation and disinfection. On a consumption basis, sodium hypochlorite accounted for 91% of total global hypochlorite use, with calcium hypochlorite at 9%. Lithium and potassium hypochlorite account for a negligible share.

Sodium hypochlorite is commonly referred to as “liquid chlorine bleach” throughout the world. In the United States, it is used by households as a laundry bleach or household cleaner as a 6.15% solution (equivalent to 64.2 grams or 5.9 weight percent available chlorine per liter of solution). In Western Europe, concentrations range around 2.5–8.5%, with the average between 4% and 5% concentration. It is also used in municipal and industrial applications as a 12.6% sodium hypochlorite solution (equivalent to 120 grams or 12.0 weight percent available chlorine per liter of solution).

The following pie chart shows world consumption of sodium hypochlorite:

In the household, sodium hypochlorite is used principally for household laundry bleaching and disinfection. Use of household bleach has increased during the past few years, with the growing concerns over infectious diseases. Mold and mildew became an issue in the U.S. Gulf Coast region as a result of hurricane damage. The number of household disinfectant products containing chlorine compounds has increased in the past few years, aimed at being convenient and easy to use. Global demand for disinfectants and antimicrobials is forecast to grow at over 4% annually during 2008–2013, because of consumer concern over foodborne pathogens and recent outbreaks of Severe Acute Respiratory Syndrome (SARS), avian influenza and influenza H1N1 (swine flu). Consumption of hypochlorites is forecast to grow only 1.4%, but is dependent on the region.

Consumption of sodium hypochlorite in laundry bleach applications currently accounts for 67% of usage, with disinfectant use accounting for the remaining 33%. Clorox and other suppliers are attempting to create new applications and increase sales of bleach, with emphasis on its disinfectant characteristics as the primary focus. Use as bleach has been declining and this is expected to continue, as a result of a declining elderly population that used bleach on a regular basis and a reduction of shelf space at retail chains to increase dollar-per-cubic-foot sales. In addition, consumers and manufacturers are affected by the “going green” movement, with a shift to more environmentally friendly products. Supermarkets/hypermarkets account for over 55% of the retail sales value, with independent retailers (36%), convenience stores (3%) and all other (6%) accounting for the remainder.

The World Bank estimates that 1.1 billion people globally lack access to safe drinking water, 2.5 billion lack adequate sanitization, and nearly 50% of the world’s hospital beds are populated by people who have contracted waterborne diseases. Furthermore, if present consumption rates continue, in 25 years, the world will be using 90% of all available freshwater. As a result, desalination and water reuse will become a more important source of freshwater. Currently, there are over 10,000 desalination plants in the world, in at least 120 countries. There are over 100 water reuse facilities.

Both desalination and water reuse technology will require reliable disinfection technologies, some of which include sodium hypochlorite either in pre- or posttreatment to prevent biological fouling within the system or distribution system. At present, nearly 75% of all global desalination capacity is in the Middle East, Persian Gulf and North Africa. In the past five years, reverse osmosis (RO) has become the leading desalination technology, replacing multistage flash distillation. Most plants installed in Saudi Arabia, Kuwait and the United Arab Emirates use distillation. Most plants in the United States rely upon RO and vapor compression. Four states account for most of U.S. capacity—Florida, California, Arizona and Texas. As a result, consumption of sodium hypochlorite is forecast to continue to grow. (For more information on global water supply issues, see the Safe & Sustainable Chemicals report on Water and Sustainability in the 21st Century.)

The largest consumption market for calcium hypochlorite is swimming pool sanitization, but use for disinfection in food and aquaculture applications is forecast to continue to grow globally. Aquaculture has been growing at over 9% annually for the past ten years and production is forecast to continue at that pace and double in the next twelve to fifteen years. All regions are growing and require disinfection. Asia is the leading producer of aquaculture, accounting for nearly 91% of all production in 2007 and 2008, with China being the largest producer.

Calcium hypochlorite is consumed in the United States mostly by the swimming pool industry; other major uses for calcium hypochlorite include food applications, water disinfection and health care. Consumption of calcium hypochlorite in Western Europe is primarily for swimming pool sanitization. In Russia, however, it is used mainly for odor control. The majority of Japanese production is exported. Latin America, the Middle East and Africa mainly use the product internally, with little export. China is the largest producer and exporter of calcium hypochlorite bleaching powders.