1. A vital industry providing essential products

Chlorine may be best known for its use as a drinking water disinfectant. Less well known is chlorine chemistry’s role in producing thousands of other beneficial products. As a vital component of materials used in automobiles, construction, crop protection, electronics, aerospace, pharmaceuticals and manufacturing, chlorine chemistry helps to improve health and safety, and enhance quality of life. This section provides an introduction to the chlor-alkali industry, and examines chlorine chemistry’s contributions to the three pillars of sustainability—society, economy and the environment.

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Underpinning global economies

There are more than 500 chlor-alkali producers and over 650 sites around the world, with a total production capacity of 58 million metric tonnes of chlorine and 62 million metric tones of its co-product, caustic soda (sodium hydroxide) per year. The industry directly employs an estimated 136,000 people worldwide and creates many more jobs in downstream and closely related industries. In the U.S. alone, the total economic contribution of the industry is estimated to be over $2 billion. Chlorine and sodium hydroxide are used in more than half of all commercial chemistry applications to create hundreds of secondary compounds that in turn contribute to plastics, pharmaceuticals and thousands of other products. The largest use of chlorine is in the production of polyvinyl chloride (PVC or vinyl), a versatile plastic used in construction materials, automobile components, medical devices and many other applications. Other chlorine derivatives include isocyanates and oxygenates (used for upholstery and insulation), chloromethanes (silicon rubber), epichlorohydrin (printed circuits), solvents (adhesives), and other organics (detergents). Chlor-alkali consumption is expected to grow at an annual rate of 3.4% through 2010, with much of this growth concentrated in China, India and other developing economies.

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Production technologies

The basic raw materials for chlorine chemistry are salt (sodium chloride), water and energy. Nearly all chlorine and sodium hydroxide production is based on the chlor-alkali process, which involves applying a direct electric current to a brine (water and sodium chloride) solution to produce chlorine, sodium hydroxide and hydrogen. The first commercial production of chlorine using electrolysis was in 1888. There are three main electrolytic production technologies used in the chlor-alkali industry – the diaphragm, mercury and membrane cell processes. Each technology uses a different method of keeping the chlorine separated from the hydrogen and sodium hydroxide. Adoption of these production processes varies significantly from region to region.

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Essential products

The industry makes a significant social contribution—and offers products and technology to improve lives and help to achieve the Millennium Development Goals.

Healthcare: Chlorine-based products play a key role in medical devices and pharmaceuticals. More than 90% of pharmaceuticals contain or are manufactured using chlorine, including products to treat HIV/AIDS, allergies, arthritis, cancer, depression, diabetes, heart disease, hypertension, infections, pneumonia and ulcers. Through its use in PVC, chlorine also contributes to safety in tamper-resistant pharmaceutical packaging and in “blister” packs, which help extend shelf-life and make it easier for patients to take the correct dose. One-quarter of medical devices contain chlorine. Chlorine-based plastics are used to make intravenous drips and blood bags, sterile tubing and packaging, prosthetics and heart catheters. Chlorine is also used to make semiconductors for diagnostic instruments.

In hospitals, chlorine compounds help protect patients from infections through their use in cleaning and disinfection, and as antiseptics.

Nutrition: Chlorine is used in the manufacture of 86% of crop protection chemicals, which help to boost crop yields and quality. In commercial food preparation, chlorine-based products are used for:

• Disinfection of equipment and food contact surfaces (killing food-borne bacteria such as Salmonella, Escherichia coli and Campylobacter)
• Making packaging to keep food fresh and prevent contamination.

Public safety: Chlorine’s role in public safety includes the following:

• Decontaminating public water supplies damaged by natural disasters, such as hurricanes, floods, tornadoes and earthquakes, and preventing mold growth, particularly as flood waters recede
• Materials used in protective equipment for police, fire and ambulance services, such as bullet-resistant vests, face shields and helmets, and fire-resistant clothing
• Communications equipment and components for emergency services, such as radios, mobile telephones and microprocessors.

Quality of life: Chlorine chemistry’s role in improving quality of life includes:

• Providing long-lasting, energy-efficient materials for home construction, such as PVC window frames, siding and pipes, insulation, adhesives, paints and carpets
• Use in toiletries and cosmetics, contact lenses, computers, televisions and compact discs
• Use in equipment for many leisure activities, such as soccer balls, tents, waterproof clothing, skateboards, tennis rackets and skis
• Providing durable materials for automotive components such as upholstery, bumpers and mats, dashboards, fan and alternator belts, hoses, gaskets and seals.

Environmental protection: Chlorine, sodium hydroxide and downstream products provide a range of environmental benefits, including:

• PVC is one of the most resource efficient materials for many applications. Many PvC products have a long life, ensuring maximum use is made of natural resources used in their manufacture. In over 50% of PVC applications, the products last over 35 years.
• PVC requires less oil for production and emits about 50% less carbon dioxide than some other polymers if incinerated at the end of its useful life. It can be recycled on an industrial scale for most applications.
• Clean solar energy reduces society’s dependence on fossil fuels. It is harnessed by solar panels constructed of thousands of wafers of silicon, purified using chlorine chemistry.
• Sodium hydroxide neutralizes acidic environmental pollution. It is used to control and remediate acid mine drainage, pollution that can severely degrade the habitat and water quality of receiving streams.
• Used aluminum beverage cans and packaging containers represent a large source of aluminum in the municipal solid waste stream. Chlorine gas is bubbled through molten aluminum scrap during the recycling process to reduce magnesium and other impurities in the aluminum melt.
• Hydrochloric acid is used to remediate soils polluted by mining and metallurgical activities.
• PVC pipes are strong, durable and immune to corrosion, helping to minimize water loss in municipal water systems.
• Many energy efficient building products, such as foam insulation and PVC windows, are based on chlorine chemistry.

Safe drinking water: Today, 1.1 billion people do not have access to safe water sources, and 1.7 million deaths per year are caused by diarrheal diseases—the vast majority among children under five—according to the World Health Organization (WHO). Some 94% of the burden of diarrheal disease is attributable to environmental and associated risk factors such as unsafe drinking water and poor sanitation and hygiene. At the 2002 World Summit on Sustainable

Development, the global community committed to halve by 2015 the proportion of people without access to safe drinking water and basic sanitation. The World health Organization notes that “reducing the disease burden of environmental risk factors will contribute significantly to the Millennium Development Goals (MDGs).”Improving global access to safe water and sanitation plays a key role in many MDG targets, including eradicating extreme poverty and hunger (by helping avoid water-related illness and lost earnings), achieving universal primary education (safe water and good latrines encourage school attendance), promoting gender equality and empowering women (by saving the time needed to collect water and care for sick children), reducing child mortality (by reducing water-borne illness), improving maternal health (by reducing contamination in the home and helping reduce infection risks around childbirth), and ensuring environmental sustainability (by reducing pressures on ecosystems from water- and air-borne contamination).

Chlorine-based products, such as disinfectants and PVC pipes, are essential to help meet this global challenge. For more than 100 years, chlorine has been added to drinking water to kill microorganisms and prevent diseases such as cholera and typhoid fever. Chlorine has the major advantage of providing a “residual” level of disinfectant that remains to help protect treated water all the way to the tap. In addition to purifying water, chlorine helps remove tastes and odors, controls the growth of slime and algae in pipes and storage tanks, and helps to remove unwanted nitrogen compounds from water.

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“Safe Water Delivered Safely”

Under the banner of “Safe water delivered safely,” WCC supports a range of humanitarian partnerships and international relief efforts to improve access to safe drinking water, a key building block of sustainable development:

• Household water treatment: WCC is a partner of the World health Organization’s household Water Treatment Network. Through this network, WCC supports the widespread adoption of simple, low-cost technologies to disinfect and safely store water for household use. In communities where safe water supplies are not available, use of specially packaged chlorine disinfectants in individual households been shown to reduce the incidence of diarrhea by 25-50%.
• West Africa Water Initiative: WCC actively supports the West Africa Water Initiative (WAWI), a multi-partner alliance working in some of the most arid regions of western Africa. WAWI projects are focused on providing sustainable water supplies, reducing disease and improving water management in Ghana, Mali and Niger. Unveiled at the 2002 World Summit on Sustainable Development, WAWI is a leading example of the “partnership” model for achieving the United Nations’ Millennium Development Goals. WCC is providing PVC pipe and other materials for use by World vision, UNICEF and other WAWI partners to construct bore wells and sanitary latrines. WAWI projects are expected to improve the lives of more than 500,000 people by 2010.
• Disaster relief: WCC and its members have a long-standing commitment to supporting water and sanitation efforts in international disaster relief efforts. In the wake of the tsunami that hit South Asia in December 2004, WhO advised that ensuring access to safe water was critical to preventing outbreaks of waterborne diseases such as cholera and typhoid. Within days, WCC member associations in the U.S. and Europe coordinated an industry response, raising over $150,000 to aid Red Cross water and sanitation efforts. This is in addition to substantial efforts by individual member companies.

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Exploring the branches of the Chlorine Tree

To showcase how chlorine and sodium hydroxide help ensure the health, safety and comfort of people around the world, the Chlorine Chemistry Division of the American Chemistry Council created the Chlorine Tree website (www.chlorinetree.org), a virtual tour of the thousands of products created through chlorine chemistry.

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