Burton Hamner

[call-out: "the economic opportunity is significant, the market is responsive, and there are good indicators that the concept [of using Nepali-grown vegetable dyes] is technically feasible. And success would mean that industrial ecology is real enough to walk on"]

Oriental carpets are one of the most popular products of Asia. Produced from the Middle East to China, they have long been known for their complex designs and rich colors. Traditionally, the dyes used to color the wool and other materials from which carpets are made were obtained from a variety of plants and other natural sources.

Most of the natural dyes were collected in the wild from sources such as oak tree galls, larkspur, woad, indigo, madder, and cochineal. Only a few of the sources, such as indigo, were intensively cultivated. As synthetic dyes were developed, reliance on natural dye sources diminished. Synthetic azo dyes (an acid direct dye that yields yellow or orange-red) were introduced to many weaving areas between 1875 and 1890. Synthetic indigo was developed in 1897, and by 1914, only 4% of the indigo produced was extracted from plants. As the carpet industry has grown and commercial production has demanded more reliable supplies, vegetable dyes have been largely replaced by synthetic dyes, including acid, reactive, chrome, and metal-complex formulations.

In the Kingdom of Nepal this has led to a major environmental problem with significant ecosystem implications, and also a major opportunity for industrial ecology. When the Chinese army occupied Tibet in the 1950s, a flood of refugees entered Nepal. The refugees brought with them their traditional carpet-weaving practices. Searching for income, they began making carpets, and in 1964, the first commercial shipment of hand-knotted carpets was exported from Nepal. Today the carpet industry is the largest industry in Nepal. In 1995/96, Nepal exported .9 million square meters of carpet, providing the country’s largest source of foreign income.

Hundreds of small producers make carpet in Nepal. Over 90% are located in the relatively small Kathmandu Valley. Imported wool is dyed in vats and woven into carpets. The carpets are then washed repeatedly before being trimmed to finish. The vast majority of dyes used are synthetics imported from European producers such as Sandoz and Ciba-Giegy. The dyeing process is largely done with few process controls and the transfer efficiency of dye onto the wool is often quite poor. Consequently, large quantities of dyes are discharged into the shallow rivers of the Kathmandu Valley. Waste dyes are the largest chemical pollutant of Nepal rivers, and the once-clean rivers of the Kathmandu Valley are now black.

A Nepali organization, the Institute for Legal Research and Resources (ILRR), is working with the carpet industry to investigate the feasibility of commercial-scale application of vegetable dyes to substitute for imported synthetic dyes. With financial support from the US-Asia Environmental Partnership, through the Asia Foundation, ILRR has hired two chemists to investigate the challenges to using vegetable dyes. These include color quality and fastness, but the most significant obstacle is obtaining sufficient supply. Many companies produce carpets according to orders from foreign buyers, and one company owner says that it would take six months to get sufficient "traditional" vegetable dyes for a typical order.

Yet the advantages of overcoming these obstacles are striking. Imported dyes are the second-biggest expense to the Nepal carpet industry, after imported wool, and one for which scarce foreign exchange must be used. If vegetable dyes could be grown in Nepal in sufficient quantity it would significantly improve the balance of payments of the country. It would also potentially reduce carpet production costs and make Nepali carpets more competitive in the global carpet market. This economic rationale is increasing the interest of the Nepal government in the ILRR project.

The environmental and health implications are also significant. The metals in imported synthetic dyes are carried downstream from Kathmandu through thousands of miles of Indian rivers, potentially affecting millions of people. Dozens of carpet dyers are known to have suffered acute health problems from contact with the synthetic dyes and are probably the tip of the iceberg. It is estimated that the Nepal carpet industry employs between 100,000 and 300,000 people, many of whom come into contact with raw dyestuffs regularly and who can be expected to have chronic if not acute reactions to the chemicals.

Production of vegetable dyes could also benefit Nepal’s agricultural economy. One of the world’s poorest countries, Nepal greatly needs new kinds of cash crops. The impact of diverting the tens of millions of dollars currently paid to European dye producers to Nepal farmers would be significant.

The carpet market is quite responsive to the use of vegetable dyes. Major carpet dealers distinguish vegetable-dyed from synthetic-dyed carpets for their customers although they usually argue that vegetable dyes are not necessarily of better durability (and in the case of acidic black tannin dyes the durability is worse). Germany is the biggest importer of Nepalese carpets with 80% of the purchases, and German buyers are increasingly conscious of the use of synthetic dyes that have negative environmental effects. The carpet industry has a product labeling system called Rugmark that represents carpets made without the use of child labor, and the Rugmark Nepal Foundation is considering expanding the use of the label to cover environmentally responsible production as well. There is therefore a potential market-driven mechanism to promote vegetable dye use in the carpet industry.

Some dye producers are specializing in natural dyes specifically to respond to market demand. One company based in Colorado, Allegro Natural Dyes, Inc., produces a full range of dye colors from five natural sources: indigo, osage, madder, cutch, and cochineal.

Know-how for large-scale vegetable dyeing is increasing. According to several American carpet dealers interviewed by the author, in the past twenty years there has been a huge increase in the quantity and variety of new vegetable dyed rugs available. The trend began in western Turkey in the late 1960's, but knowledge of vegetable dyeing has now been re-introduced into Afghanistan, India, Pakistan, and Nepal.

Current know-how is augmented by an extensive literature on natural dyes, dating back centuries. For example, the book Dyer's Instructor, by pattern dyer David Smith, was published in 1860 with nearly 800 recipes for dyes. Now hobbyists and return-to-nature advocates are adding rapidly to the resources available. Over a dozen books on natural dyes have been published in the last few decades.

Despite these resources, Nepal faces significant challenges in substituting locally-grown vegetable dyes for imported synthetics. Research is needed on the types of dye plants that would grow best in Nepal’s varied climatic conditions. If sufficient quantities can be produced, extensive quality control will need to be instituted to satisfy foreign buyers who want large lots of identical carpets. Although vegetable dyes are free of heavy metals, it is not clear that they produce less biological or chemical oxygen demand in wastewaters, or that they do not cause adverse health effects in some workers. Integrating Nepal’s carpet and agricultural industries would likely run into other challenges that are now unforeseen. Perhaps the greatest challenge will be getting the various organizations in Nepal that would be affected by the change to cooperate with each other. However, the economic opportunity is significant, the market is responsive, and there are good indicators that the concept is technically feasible. And success would mean that industrial ecology is real enough to walk on.