Chlor-alkali’s acid test

Caustic - Chlorine Sector - Under Pressure

Author: Sunita Narain

What would you say of an industry that takes common salt and turns it into one of the most environmentally deadly substances we know of today, namely chlorine?

And what if in its production process it uses yet another deadly substance, mercury? We are talking about India’s caustic-chlorine industry. Centre for Science and Environment’s (CSE) Green Rating Project has recently completed the environmental rating of this sector’s life cycle. Fascinating journey it was. Green rating, as CSE practices it, is a great teacher of detail and substance. It took us over one year to understand the sector. During this period, we took it apart from skin to bones to its entrails and then worked carefully to see what would be the best way to put it together again. Something like virtual reengineering for a green industry.

When we began the exercise, the caustic-chlorine sector sounded very dull. It had none of the environmental tragedies of the paper sector or the glamourhorror of the automobile sector — both of which we had rated earlier (see ‘Enter the green rating project’ Down To Earth, Vol 8, No 5, and ‘Setting out’ Down To Earth, Vol 10, No 13). In ignorance I asked my colleague Chandra Bhushan, who coordinates this programme, what is this industry? His stock answer was that this sector manufactures the lifeline for the modern industrial sector. Interesting. Yes. But still what is its environmental story?

I was to eat my words. As information on the sector unfolded, it became clear that this rating is the stuff that Hindi films are made of. It has romance — making modern chemicals from the salt of the seas.

It has success — as early as in 1985, an oleum leak in the Delhi-based Sriram Fertilisers and the subsequent legal directions forced the entire sector to substantially clean up its safety record. Some parts of the industry are even close to the global best industry in this sector. But still, action is only when there is a push. So the industry works on safety of chlorine, but forgets about another equally dangerous chemical — hydrogen, which is highly inflammable. It improves safety in the plant, but does little to inform people living outside its factory compound on the dangers and emergency planning.

It has tragedy — mercury is used in the process. Before we began work we heard from regulators that the problem of mercury contamination from this sector “is taken care of”. But as we fished and fished some more, we found to our horror that not only is the problem not taken care of, but it is of deadly and frightening proportions. We learnt the bestkept secret was that a large proportion of the mercury that enters the plant is not accounted for. Nobody knows where it goes. What we have found on this deadly mercury trail still leaves unanswered many issues. But most of all it calls for urgent action — to set new regulations for these plants and, if nothing else works, to close down these plants as fast as possible. It is clear with the data we have on mercury that a massive human tragedy is in the making.

It has drama — it manufacturers a product like chlorine which when is used by a chemical industry to manufacture chlorofluorocarbons (CFCs), which we now know are responsible for damaging the earth’s ozone layer, and because of which, we have increased incidences of cancers. It is now being used in the plastic industry to manufacture polyvinylchloride or PVC as we know it. When burnt it releases dioxins — deadly toxins. Wonder chemical or chemical of death? Who is going to steer the industry towards, not just cleaner production. But to manufacture “clean” products. Clearly, it would be in the interest of the caustic-chlorine industry to ensure long-term usage of their product. In that case, should they not be steering the entire industry towards finding environmentally safe uses? But this needs leadership. It needs foresight.

Most of all, the terms of engagement must change. The circle of responsibility must be extended. The green rating of the caustic-chlorine teaches us this.

Pollution unmasked

The Green Rating Project unveils the environmental face of India’s caustic-chlorine industry

It’s a Catch-22 situation. How does one rate an industry where the pollution is minimal at the production plant and peaks the moment the product leaves the factory gates? How does one rate an industry that is the mother of all chemical industries? How does one rate an industry that has no control over the products it manufactures? These are the dilemmas of rating India’s caustic-chlorine industry, an intermediary industry that supplies precious raw material for almost all products. But also one that is fast becoming a major environmental and health hazard the world over.

That’s why the third rating of the Centre for Science and Environment’s Green Rating Project (GRP) is significant. It is an attempt to study this industry, whose environmental performance was as yet a grey area.

The issues that the caustic and chlorine industry throw up are many. Chlorine and caustic soda are used extensively by industries to make products like plastics and pesticides that are highly detrimental to the environment. Even the storage and transportation of products like chlorine is a highly risky business, especially in a densely populated country like India. Moreover, the mercury cell process for producing caustic soda and chlorine is fast emerging as a major environmental and human health concern.

Indicator of industrialisation

The chemical industry in India has been one of the fastest growing industries since independence. And the caustic-chlorine industry is considered as a symbol of the level of industrialisation in the country. The basic inorganic and organic chemicals produced in the chemical industry provide the building blocks for several downstream industries but the hallmark of the industry is pollution — during production, conversion to various end products and on disposal. Caustic soda and chlorine are used in almost all industries in some form or the other. The importance of the sector can be gauged by the fact that the caustic-chlorine industry is among the top 20 largest chemical industries in the world.

The Indian caustic-chlorine industry is about four per cent of the global industry, which is comparatively small. The annual production capacity is 2.25 million tonnes, but rarely more than 1.8 million tonnes is produced. The industry comprises about 25 large companies that alone account for 90 per cent of production. In India, caustic soda is primarily used in the manufacture of pulp and paper, detergents, viscose, aluminium, petroleum refining and metal cleaning. Chlorine is mainly used for hydrochloric acid (HCl) production, pulp and paper bleaching in polyvinylchloride (PVC) and other chemicals.

The market conditions are such that caustic soda is in demand in India, while chlorine is not. Globally, the industry requires more chlorine than caustic soda. Though Indian companies have excess chlorine, they cannot export it simply because of the major hazards associated with the transportation of chlorine.

Chlorine also finds a place in the list of toxic and hazardous substances banned for transnational transportation under the Basel Convention. As a result, India is faced with a double edged sword — on one hand, it has a growing chlorine stock that it cannot dispose and on the other hand, the dumping of caustic soda is forcing the sector to compete with international prices. This has pushed the sector to desperation and it has repeatedly looked for government intervention.

Background pollution

It is ironic that companies that appear green and clean at the production plant are sometimes the ones that produce the most environmentally-damaging products. Just as in the case of the caustic-chlorine sector. It is a sector where 70 per cent of production is at par with the global best technology — membrane cells. But the remaining 30 per cent production from the polluting mercury cell technology alone accounts for 40 per cent of mercury pollution in India from industrial operations (except coal based uses). There is also a paradox: it is a sector that saved millions of lives by providing clean drinking water, but is also responsible for compromising the environment as a safer place and for maintaining the fertilisation and abundance of life. The industry is accused of producing products that mimics hormones in animals, and accumulates in the foodchain.

Shades of green

Indian caustic-chlorine industry operates in extreme. At one level, it is as good as the global best performance, and at the other it is as bad as it can get. GRP has found that the level of environment management of the Indian causticchlorine industry is nothing less than the global best. The sector has slowly moved away from the toxic mercury cell process and today more than 70 per cent of the sector uses the best available membrane cell technology in their production plant. Compared to Europe and the US, where more companies are using the polluting mercury cell and diaphragm cell technology respectively, the performance of Indian causticchlorine sector in moving towards membrane cell technology is significant.

Even at the production plant, the performance of Indian caustic-chlorine sector in energy and raw material consumption is more or less comparable to the global best performance. But in water consumption and toxic mercury emissions it fares poorly. The energy consumed by Indian causticchlorine industry is probably the least in the world and their consumption efficiency too rivals the global best performance.

But the amount of mercury pollution it generates is also huge. In addition, to make sure that their eco-friendliness is recognised, companies have obtained internationally-recognised certifications for their environment and health and safety performance. The percentage of total companies having ISO 14001 for environment and ISO 18001 for health and safety is probably the maximum in Indian caustic-chlorine industry.

Out of the factory gates

The ultimate use of chlorine is not within the control of the caustic-chlorine industry, rather it depends on the downstream industry that makes environmentally damaging products like plastics, pesticides and organochlorines. Serious questions of adverse health and environmental effects of chlorine and chlorinated compounds have been raised, with many chlorinated compounds accused of toxic behaviour, mimicking hormones in animals, and accumulating in the foodchain. These compounds could contribute up to 20 per cent of the greenhouse effect. The ozone hole is created by chlorofluorocarbons (CFCs) — a chlorinated product. Even though the caustic-chlorine industry does not have control over downstream uses, it has to take the responsibility for the environmental impact that takes place during the downstream use of its products, since its economics are linked with the downstream uses. If downstream uses get banned due to environmental pressures, the causticchlorine industry too will close down.

With increase in scientific research on the impact of chlorine and chlorinated products on environment, caustic-chlorine industry is likely to come under more environmental pressures. Therefore, it is in the interest of the industry to make sure that its products are used responsibly.

Raw material sourcing phase

To rate the companies on the raw material sourcing phase, GRP used the following indicators: the quality of input salt, transportation of salt, self-sourcing of water (water harvesting) and the use of renewable and clean fuels. The Indian caustic-chlorine industry has performed poorly in this parameter, not because the sector is very polluting but because it could have been far cleaner than what it is today. Compared to industries like pulp and paper and automobile (earlier rated by GRP), the impact of caustic-chlorine industry is insignificant. Still, there is vast scope for improvement.

For instance, Indian companies can meet their water needs by undertaking water harvesting within the plant. But only three of the 22 companies do so. Others still rely on groundwater, though many of them are located in waterscarce areas. Similarly, despite the potential of meeting about 30 per cent of the energy requirement from hydrogen (which is produced as a by-product and is one of the cleanest fuels), none of the Indian companies use it as a fuel. In fact, companies prefer to vent hydrogen (about one-third of the total hydrogen produced is vented).

The quality of salt sourced is also very poor. This leads to high pollution at the production plant, including substantial increase in toxic mercury pollution. Though the possibilities to use better quality salt exist, companies are only happy to buy cheap and impure salt from the unorganised sector. This in turn increases toxic pollutants inside the production plant.

Worse still, the sector transports this salt from as far as 500 km (average transportation of the sector) releasing as much as 90 kg carbon dioxide to produce one tonne of caustic soda. Companies discount salt conservation, as the cost of the salt is very low. Though this has little economic implication, it has high environmental cost as salt released from the plant — mainly through rainwater during rainy seasons — has great potential to contaminate both soil and groundwater.

These are the reasons why the Indian caustic-chlorine sector has scored just 20.9 per cent marks. Even the best company, Shriram Alkalis & Chemicals Ltd, achieved only 41.4 per cent marks. The scope for improvement is enormous but the aspirations of companies seem very low. This will have to change if companies want to survive in a competitive world.

Product use and disposal phase

When released into the environment, caustic-chlorine products like chlorine, hydrogen and caustic soda can cause serious damage to the environment and human health. However, chlorine and chlorinated compounds, that drive the caustic-chlorine sector worldwide, are far more dangerous. They have been linked to diseases like cancer, and could be leading to fertility-related problems.

To counter this threat, companies worldwide are working towards chlorine product stewardship, whereby a company ensures that there is almost negligible pollution from the cradle to grave of a product. Sadly, Indian companies have no clue about product stewardship. Similarly, even as companies worldwide, under pressure from environmental groups, are moving away from investing in PVC, Indian companies’ dream is to invest in PVC. No wonder the Indian caustic-chlorine sector has performed poorly in product use and disposal phase obtaining just 21 per cent marks. Even the best company, Indian Petrochemicals Corporation Ltd, has just scored 36 per cent marks.

The sector has done reasonably well in in-plant product use and disposal management, but has fared poorly in ‘extended responsibility and product stewardship’. For instance, most companies sell contaminated sulphuric acid, a byproduct, at throwaway prices to informal sectors, which uses it very inefficiently creating huge pollution.

Another issue that warrants immediate attention is the transportation of a toxic chemical like chlorine. Currently, chlorine is transported by road. In a country with a high population density, even a single incident of chlorine release can kill hundreds of people.

Production and conversion phase

The production process of the caustic-chlorine industry is simple: salt and water is mixed to make brine solution after which energy is passed through the solution.

The result is a chemical separation and association of the molecules, which results in products like caustic soda, chlorine and hydrogen. However, the simplicity of the process masks a highly complex industry that has a huge impact on health and environment.

Though companies were rated for more than 100 parameters in this phase, the key environmental issues on which the rating was undertaken were energy consumption, mercury pollution and chlorine leakage/pollution.

With 33.8 per cent marks, the performance of the Indian caustic-chlorine sector in production and conversion phase is average; the top company being Chemfab Alkalis Ltd. On the one hand, the sector’s performance in areas such as energy and salt are at par with the global best and on the other, its performance in mercury pollution, water consumption, pollution prevention initiatives and recycle and reuse practices is as bad as it can get. It’s a mixed bag in the end. The key findings:

• The average eco-efficiency (ratio of output to input) of the sector is about 52.5 per cent. This is a good eco-efficiency rate if compared with other industrial sectors, but poor because the caustic-chlorine industry can achieve as much as 90 per cent.
• The resource consumption efficiency of Indian companies is at par with the best companies in salt and energy world wide, but very poor in water and mercury. Water consumption is thrice as high as the global companies and mercury consumption is at least 50 times higher than the best companies in the world.
• The sector is slowly moving towards cleaner technology — all new capacity addition has been in the form of membrane cells and the use of mercury cells have decreased substantially.
• Though caustic soda production from mercury cell based companies has decreased, mercury pollution remains very high. Currently, 70 tonnes of mercury is released into the environment every year by the existing mercury cell plants and this trend is increasing.
• Very few companies are recycling and reusing the waste generated (mainly wastewater and brine sludge).
• Membrane cell technology is far superior to mercury cell technology. Membrane cell companies have scored twice as much as mercury cell companies. Interestingly, companies partly shifting their mercury cell capacity to membrane cell are doing more environment damage.

Corporate environment management

It’s more hype than substance. Most companies flash ISO 14001 and ISO 18000 certifications to cover up their poor environmental track record.

GRP found that though 45 per cent companies possessed ISO 14001 certifications, the sector barely scored 36 per cent marks in corporate environment management. The reason is simple: the annual environment audits of the companies is as bad as the annual environment statement that they submit to the PCBs. Precious little has been done to spread awareness among employees about pollution. GRP researchers have often seen workers collecting mercury using bare hands in mercury cell companies and companies disposing their hypo sludge in the open without treatment.

For most Indian caustic-chlorine companies R&D means just testing biological oxygen demand (BOD) and chemical oxygen demand (COD) in wastewater and testing the purity of salt in obscure labs. Companies are content with just displaying their environment policy at the factory gates, but have failed to map an off-site disaster management plan. Most companies prefer to ignore community outreach programmes by shifting the onus on to the local administration.

Mercury rising

With lax regulations and a huge mercury loss unaccounted for, a disaster is waiting to happen in India

Although there has been a belated shift from the polluting mercury cell technology to the membrane cells, mercury pollution in India is still very high. India does not produce mercury and relies completely on imports. Between 1998-2001, the annual mercury imports stood at 170-190 tonnes, which is 10 per cent of the global mercury consumption. Mercury consumption by Indian caustic-chlorine companies is at least 50 times higher than the average European consumption.

Though mercury is not supposed to be consumed in the process, it gets lost during operation as soon as it is used. This has led to 70 tonnes of mercury entering the environment every year by existing mercury cell plants. And this trend is only increasing.

Mercury also finds its use in clinical thermometers, fluorescence lamps, metal switches, batteries, pesticides and certain pharmaceutical drugs and agricultural products. All these products too have a short life and they find their way into the environment shortly after they are disposed. Assuming that only 50 per cent of the mercury is released by these industries, the total mercury pollution load generated every year (including the caustic-chlorine industry) will be about 125 tonnes of elemental mercury. This is about five times more than the total mercury compounds dumped into the Minamata Bay in Japan in 36 years (see box: Mercurial deaths). This means that the mercury pollution being generated in India every year is equivalent to five Minamata disasters.

MERCURIAL DEATHS   The incident that blew the whistle on the dangers of mercury poisoning In 1907, the Chisso Corporation built a factory for manufacturing petrochemicals and plastics in a small fishing village of Japan situated along the shore of Minamata bay. From 1932 to 1968, the corporation dumped an estimated 27 tonnes of mercury compounds into the bay. The first signs of the effects of this dumping began to surface in 1925, when the fish population started declining. But it was only during the mid-1950s that the effects were seen in animals and humans, who consumed the fish. Birds started dying. People began to experience numbness in their limbs and lips. Their speech slurred and their vision got constricted. Some even suffered brain damage. Most victims complained of severe convulsions, intermittent loss of consciousness, repeated lapses into crazed mental states and then finally slipped into coma. With the onset of a very high fever, they would die. As of 1992, the number of people officially diagnosed as having ‘Minamata disease’ totalled 2,252; 1,043 were dead. The corporation’s attempts to cover up the matter proved unsuccessful. And despite the victims testifying, the United Nations did not take any steps to prevent further contamination.

The mercury cell companies alone release at least 75 times more mercury than what was disposed every year in Minamata.

Unaccounted threat Ideally, mercury lost in the process should get loaded into the environment through wastes and products. So there should be no difference between the input mercury and mercury released from various outputs. But data collected by GRP reveals that there is a large difference in the mercury balance between the input mercury and mercury released into the environment through various sources. GRP has found that as much as 44 per cent of mercury loss goes unaccounted and even companies have no clue about this huge alarming loss. Earlier estimates (1982) by the Central Pollution Control Board (CPCB) of mercury loss underplay the magnitude of the problem. Worse still, the character of mercury is such that it is a globetrotter.

Studies have revealed how mercury pollution caused in Europe can be found in Antarctica and Africa. This makes the unaccounted disappearance of 44 per cent mercury in India a major health hazard. It is an unknown enemy. And regulations in India are such that they are unable to check and control mercury pollution.

Lax regulations

The focus of regulations for mercury pollution from mercury cell plants in India is on placing checks on mercury concentration from various point sources rather than putting a check on total mercury pollution load entering the environment. This is in contrast with regulations being implemented in Europe where along with the concentration, regulation on total mercury being released from the plant exists.

The existing regulatory standards of India on mercury pollution from caustic-chlorine industry measures emissions of mercury from following point sources: mercury in wastewater and mercury from hydrogen gas holder.

The average mercury loss through wastewater in Indian mercury cells is 0.38 gm per tonne caustic soda and average mercury loss through hydrogen gas holder is 0.01gm per tonne caustic soda. Therefore, only 0.39 gm mercury loss can be accounted as per the existing regulation.

However, the average mercury consumption in Indian mercury cells is 146.6 gm per tonne caustic soda. This means that the regulatory standards are only regulating 0.3 per cent of the total pollution. This alone sums up the effectiveness of regulations in controlling mercury pollution. Even though the regulations on concentration of mercury from various point sources in India and Europe are very much similar, the absence of total mercury input regulation in India has resulted in the average mercury emissions being as high as 146 grammes per metric tonnes (gm/mt) caustic soda from mercury cell plants. Whereas, by implementing this standard European companies have achieved mercury emissions of 1.5 gm/mt caustic soda.

The future of mercury

In most developed countries, construction of new mercury plants has been banned. The government of India too has followed suit and has banned new mercury cell plants from 1986. But unlike the developed countries where the mercury cells have been given a time frame to close down, no such time frame has been stipulated by the Indian government. Europe, for example will only have membrane cell plants from year 2010 onwards and all mercury cell plants, which currently produce six million tonnes of caustic soda every year, will be shut down. If Europe can take such decisions to protect the public health even though huge amount of money is involved, it is indeed unfortunate that Indian government has not taken any decision regarding mercury cell companies, whose size is just seven per cent of the European mercury cell sector but is releasing seven times more mercury into environment with disastrous consequences to the public health.

Similar to Europe, in India too, mercury cells should be asked to close down once their economic life ends. However, the question is whether to allow the existing mercury cell plants that have not completed their economic life, considering that their mercury emission is more than 50 times that of a European unit.

One thing that comes out very clearly from GRP analysis is that, under no circumstances can the existing mercury cell companies of India meet the mercury emission standards being currently met by the European companies. It would be almost impossible for the existing mercury cell companies of India to reduce their mercury emissions even below 50 grammes per tonne caustic soda, unless they decide to upgrade the technology substantially. The investment for this upgradation would be very high and according to some Indian experts, it would be much more viable to shift to membrane cell technology rather than asking mercury cell companies to upgrade their technology to meet European standards.

Even if we assume that on an average the mercury emissions have been reduced to 50 gm per tonne caustic soda, the total mercury emissions from Indian mercury cells will still be about 20 tonnes per annum, which is about 32 times more than the existing mercury emissions from Europe to produce equivalent caustic soda. Therefore, even for the companies whose economic life has not yet expired, it is a big public health risk to allow them to operate.

One interesting finding of GRP is that partial shifting of mercury cell to membrane cell is causing more environmental pollution than good. In these production plants, mercury cells release more mercury and their membrane cell too consume more energy and raw materials. Pollution control boards that claim that mercury pollution has been solved by partial shifting better watch out. GRP has found that instead of a decrease, there is an increase in the specific mercury pollution from these plants.

GRP has recommended that all existing mercury cell plants should be shut down by 2005. Under its various schemes to promote cleaner technologies, financial institutions should be instructed to provide loans at reduced interest rates for facilitating the changeover from mercury cell technology to membrane cell technology.

Chemical roadmap

If the industry wants to survive in an environmentally conscious world, the search for chlorine alternatives must go hand in hand with product stewardship

For the caustic-chlorine industry, the way ahead will be determined by evaluating its economic benefits vis-à-vis its environmental costs. As a multi-billiondollar 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.

BACKLASH!   A few decades ago, nobody would have imagined that pesticides like aldrin and DDT would one day be banned. But times are changing. The industry is feeling the heat due to recent research and environmental consciousness about the detrimental health effects of chlorine products. The focus is on POPs or persistent organic pollutants — a group of chemicals that are resistant to natural breakdown processes and are also highly toxic. Cracking the whip on these hazardous products is the Stockholm Convention, a global treaty to eliminate POPs. It has already eliminated all existing POPs starting with a list of 12 (known as the ‘dirty dozen’). More chemical products to be banned are on the anvil. It’s time the industry wakes up.

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.

Chemfab Alkalis Ltd stands first, followed closely by Shriram Alkalis & Chemicals Ltd. But no company qualified for the five leaves award — the highest rating. Only seven of the 25 companies won the three leaves award — all of them membrane cell-based companies. The three non-participating companies are placed at the bottom of the pile