Last month, the Tamil Nadu government introduced a bill banning the sale, storage, transport, and use of all non-recyclable plastics. As I write this, Chemplast Sanmar is planning to open a PVC plant in Cuddalore, in spite of stiff opposition from the local residents and several environmental organizations. Is PVC more benign than the recently banned non-recyclable plastics? I will try answer this in this article.

Poly Vinyl Chloride, or PVC, is produced in a four-step process. The first step is the production of ethylene dichloride (EDC). In the direct chlorination process, EDC is produced by combining chlorine and ethylene gases. In the oxychlorination process, ethylene, oxygen, and hydrochloric acid are combined to produce EDC. In the second step, EDC is used to produce vinyl chloride monomer (VCM). In the third step, VCM is polymerized to form raw PVC. The raw PVC is hard and brittle, so phthalates are added as plasticizers (or softeners). Depending on where the final PVC product is going to be used, several other additives are also added. PVC uses more additives than any other common plastic, and this has its own implications as we will see later.

Every step in the manufacture of PVC plastic releases carcinogens. The production of chlorine (by the chlor-alkali process) and EDC (by direct/oxy chlorination) all release dioxin, the most carcinogenic substance known. According to the US Environmental Protection Agency (EPA), dioxin is extraordinarily toxic, persistent, and bioaccumulative. Dioxin is distributed throughout the food chain and EPA says that current background levels are already high enough to cause noticeable health affects. Since the Cuddalore plant imports VCM, the first two dioxin producing steps are less important in the local context. However, VCM has been known to be a proven human carcinogen and US federal and state laws have recognized as much since 1974. Not only is the PVC production process highly polluting, but since the additives are not chemically bound to the PVC polymer, they can easily be leached. According to the Danish EPA, phthalates, the most commonly used plasticizers, are "the most abundant man-made environmental pollutants." They are known to cause liver, kidney, and reproductive damage, and in some cases, cancer. Several European countries have banned the use of phthalates in soft PVC toys, for they can be ingested by children when the toys are sucked or chewed.

Since the Tamil Nadu government has banned non-recyclable plastics, one may think PVC is easily recyclable, for otherwise Chemplast couldn't have secured permission to open the Cuddalore plant. This, however, is not the case. The technological and financial problems involved in PVC recycling are manifold. Since the various PVC products have a whole lot of different additives, the recycled PVC is of lower quality than virgin PVC. Because of the difference in melting temperature, PVC cannot be recycled along with other plastics. PVC recycling also releases hydrochloric acid, which is corrosive to process equipment. With so many difficulties, no doubt only a minuscule fraction of PVC gets recycled. The Association of Plastic Manufacturers in Europe (APME) reported in 1996 that only 6% of all plastics is recycled in western Europe. The fraction of PVC recycled is only 0.6%. In the US and Australia, the recycled PVC only accounts for 0.1% and 0.25% of total consumption. The European, US and Australian figures show a lower recycling rate for PVC than for any other of the commonly-used plastics. Besides technological and financial considerations, there's also an environmental aspect to recycling. Recycling only makes sense when it involves safe materials. Since PVC has so many toxic ingredients, recycling only releases more toxins. Furthermore, since recycling degrades quality, the lower quality recycled PVC will eventually end up as waste. Thus recycling is only a way of delaying the inevitable buildup of waste.

Recycling being so impractical, how then do we dispose off PVC? When PVC products outrun their utility, they are either landfilled or incinerated. Since PVC doesn't decompose quickly, its additives could leach out and pollute soil and groundwater. Landfill fires are also common releasing a range of pollutants, including heavy metal additives and dioxins. Incineration also emits dioxin and heavy metals. The German Council of Experts for Environmental Issues says: "Even assuming the possibility and technical implementation of pollution-free PVC incineration by means of end-of-pipe measures, it will remain necessary to remove the hydrochloric acid that is formed from the flue gas, to bind it as a salt and to store it ... therefore the waste volume to be stored cannot be reduced by means of incineration." More dioxin is produced when the copious chlorine-rich wastes are incinerated. The global PVC consumption since the early 1960s is about 300 million tonnes, half of which has already been disposed of in landfills and incinerators. The other half is still in use in long-life products such as construction materials, the mean lifetime of which has been estimated by the plastics industry to be about 34 years. Thus, this other half is just starting to enter the waste stream.

If so many toxic additives are involved, how about the wastes from the PVC facilities? A 1994 Greenpeace investigation of the US PVC industry found a dangerously high concentration of dioxin and Polychlorinated biphenils (PCBs) in the waste samples from VCM facilities. Incidentally, the production of PCBs had been stopped in the 80s after it was discovered that they could harm the reproduction of seals and other wildlife. In case the Cuddalore plant starts functioning, Uppanar will no doubt be polluted - Chemplast's claim that it is a backwater with no economic value to local people is a good pointer to the future.

Do we really need such rape and run industries? A few families will sure gain employment, but let this not cloud our vision. Employment opportunities needn't be so costly to the villagers and the environment. When the Gwalior Rayons factory was set up in Mavoor in Kozhikode district, the villagers were jubilant. The Chaliyar river soon turned dark with waste, the death rate due to cancer skyrocketed to 30%, and after more than 30 years of arduous struggle, the Mavoor villagers finally closed down the factory. Do we want a repeat in Cuddalore?

To conclude, PVC is not unavoidable - the Sydney 2000 Olympic stadium seating and plumbing were PVC-free. With concerted research, biopolymers can surely be made economical. Let's not forget that the first computer occupied a room 30 by 50 feet, weighed about 30 tons, and cost about $400,000!

[I have consulted and drawn liberally from several Greenpeace reports]

Ra Ravishankar

June 23, 2002