OBSERVATION: Chemical roadmap

-- For the caustic-chlorine industry, the way ahead will be determined by evaluating its economic benefits vis--vis its environmental costs. As a multi-billion-dollar industry which employs millions of people the world over, the industry makes a major impact on global economic growth. At the same time, emerging research now shows that the products and processes of the industry and its subsidiaries are posing a serious threat to the environment.

But let's first look at its many uses. Chlorine is an inherent part of modern industrial lifestyle today. We use chlorine and chlorine-based products whenever we drink a glass of water, buy food wrapped in plastic, pour bleach into a washing machine, print a computer document or drive a car. Chlorine is used in dry cleaning and 85 per cent of all pharmaceuticals use it at some point in the production process. It is also used to treat leukaemia, meningitis, malaria, typhoid and a host of other diseases. But its environmental and health impacts far outweigh its uses.

The problem of chlorine in the environment is complex. It is compounded by the fact that some organic compounds of chlorine are persistent - they are not biodegradable, or don't break down very easily. Some of these compounds bioaccumulate in the tissues of animals and humans. Worse still, some chlorine compounds have a tendency to biomagnify - the concentration of the compounds increases in animals higher up the foodchain. Research reveals that chlorinated organic compounds or organochlorines are toxic, bioaccumulative and cause a number of diseases including cancer, immune suppression, birth defects and endocrine disruption. Dioxin, a chlorinated substance produced during the manufacture of polyvinyl chloride (PVC) and when PVC is burned, is now widely recognised as a carcinogen.

Other chlorinated compounds such as chlorofluorocarbons (CFCs) and hydro chlorofluorocarbons are potential contributors to ozone depletion. One of the earliest examples of this problem was the pesticide DDT, an organic compound of chlorine, which imitates the action of certain hormones like oestrogen. Another group of chlorine compounds, polychlorinated biphenyls (PCBs), is known to cause
fertility-related problems.

Charting a course

While caustic soda is not a problem, chlorine use is an issue that will determine the survival of the Indian caustic-chlorine industry. The chemicals that are being banned/phased out in industrialised countries will soon have to be banned in India as well. But today, 11 per cent of chlorine produced in India is used for paper bleaching at a time when countries around the world are reducing its use. If this trend catches up in India, it will cost the caustic-chlorine industry dear. Consumption of chlorinated solvents such as HCL, TCE methylene chloride and PVC is bound to decline in future (see box: Backlash!). The sectors that seem least threatened and where chlorine will be used in the next few decades are the pharmaceutical industry, water disinfections and segments that use chlorine merely as a facilitator, wherein no chlorine is present in the final product.

If the industry wants to stay in this business it must find alternatives for the sound use of chlorine. Industry should also work to delink the production of caustic soda and chlorine. Though a complete phase-out may seem a distant dream, yet rapid strides made in science and technology may throw up a substitute.

Its prevalence and economic impact make out a case for chlorine today, but questions of health and environmental effects may turn the tables tomorrow and lead to a complete phasing out of chlorine-based products. In view of this, it is imperative for the caustic-chlorine industry to start thinking of chlorine product stewardship.