mercury contamination, metal contamination, Hg

Mercury Contamination

By: Sulagna Chattopadhyay
CFLs are long glass tube filled with mercury vapour and argon or xenon. As CFLs contain toxic mercury, suppliers and manufacturers need to play a pivotal role in setting in place a safe disposal system.
English Free Article Expert Column Pollution

Time and again we have investigated the need to place a safe disposal system for Compact Fluorescent Lamps (CFLs) as they contain toxic mercury. We have argued that suppliers and manufacturers need to play their part in setting in place a disposal system for this hazardous household waste. Yet we are unable to bridge the gap between profit and purpose. Bureau of Energy Efficiency (BEE) has woken up to star ratings, although consumers, retailers as well as manufacturers are completely clueless about what a star rating does. As far as they are concerned a starred product costs considerably higher than a non-starred one – which of course decides what is to be purchased. Why non starred, low priced products should sell in the market and why old stock cannot be upgraded are questions that perhaps need some answers. But that is another debate. What is pertinent however is that we have a mandate to bring about a revolution in energy efficient technologies, including increased usage of CFLs, which requires BEE to at least synergise a disposal system, (supported and funded by all the CFL manufacturers) and make serious commitments about bringing the cost of CFLs down to make it palatable for the service and poor class.

The CFL conscious elite claim they are proficient users of lighting that can save the world from greenhouse gas emissions. The link no doubt is well established and the affluent have found a new expensive toy to show concern for the future. As no heat is produced in a CFL it requires only 20 per cent of the electrical energy used by incandescent bulbs in which 90 per cent goes waste as heat rather than light. But with a rising inequality in incomes, poor India can barely afford a light bulb let alone a CFL. Starting at about Rs 100 for standard illumination requirement for almost all branded CFL, it is way beyond the Rs 10 that a two-square-meal-earning citizen dishes out for an edisonian bulb. If we are so sure that the energy efficient CFL will translate into substantial energy savings and bring down emissions levels then we should address its pricing regiment so that every Indian is able to afford a CFL without debt pangs.

Pricing is, well, another debate. Our concerns lie with a planned disposal system for the consumer, retailer as well as the manufacturer.

Read – Recommendations for Safe Disposal of CFL at


Expert speak

Article 2 Expert

The Manufacturing of CFLs

Dr B Sengupta, Member Secretary, Central Pollution Control Board, New Delhi

Elemental mercury is used in CFL production. The process involves the use of CFL shells received from in-house glass plant. For injection of mercury, the phosphor coated spiral or U shaped CFLs are fitted in the rotating disc where the required amount of mercury is injected through an injector. The temperature is maintained around 60°C, so that the elemental mercury remains like a tiny globule when the CFL is ready. After injection of mercury, the entire system is operated under vacuum; lamps are sealed and checked for leakage. About 3 to 4 mg of mercury is injected in each CFL.

Last year we studied the process at two CFL Industries in Uttarakhand at Phoenix Lamps Ltd, Dehradun and at Havell’s India Ltd. Haridwar. Phoenix uses elemental mercury while Havells uses an amalgamation of zinc and mercury in CFLs. But it was alarming to note that both these industries had no norms of safe disposal in the event of breakage, exposing the workers to mercury contamination.

We estimated that a maximum of 1 percent of production loss occurred through breakages during manufacturing and packaging in Phoenix. The arrangement for the workers was to collect breakages into a bucket with water. Fused lamps were dismantled and also collected in the bucket. Once in a fortnight, the bucket is cleaned and the liquid is passed through a gold filter. The mercury thus obtained is sealed and sent to the company from where mercury as raw material is purchased (in this case Merc) for recycling. But the shop floor where mercury is dispensed remains a source of fugitive emissions and safety norms for workers need to be put in place.

The situation was worse in Havells. Since the mercury injection takes place under vacuum through a capsule at 60°C there is likelihood of mercury getting vaporised and entering the ambient air, unlike in tube light production where the mercury injection takes place around 600°C. We have taken two ambient air samples and are waiting for its results. Also we observed that there was no collection mechanism for breakages. Although the shop floor is well ventilated, possibility of inhalation of the emissions from breakages remains. We hope that the unit in near future will place a mechanism of safe mercury disposal for its workers.

The onus on the manufacturer, I feel, does not end here. Once, the lamps have over run their period of life, a safe disposal system for the consumer needs to be put in place too.

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