Name: Carolyn

Message: Are Reactive Dyes eco-friendly?

If you are considering their use, fiber reactive dyes are eco-friendly, in most respects. The small amounts of dye you use are safe to dispose of down the drain or in your septic tank. The dyes are not very toxic or carcinogenic, unlike some direct dyes that until recent years were commonly used in all-purpose dye, and they do not require the use of toxic mordants. The heavy metal content is low for a few colors (turquoise and cherry contain about 2% copper), and zero for the rest of the colors. (See "Toxicity of Procion Dyes".) The only problem at the dyer's end is that the amount of water required to rinse out excess unattached dye can be excessive for those who are under drought conditions.

The eco-friendliness of dye synthesis is another question, one that is very difficult to answer. Dyes are manufactured in many different factories across Europe and Asia. Petroleum products are essential for the manufacture of many of the chemicals required.

Dystar is the owner of the Procion trademark. They no longer make Procion MX dyes, but they still make other fiber reactive dyes such as the Procion H-E dyes, the Remazol dyes, and the Levafix dyes (which are the same type as Drimarene K dyes). Their dyes have earned the EU label [PDF link]) and Oeko-Tex Standard 100 certification. However, other dye manufacturers may or may not follow similar standards.

The most eco-friendly garments are made from organically grown fiber that is either undyed or colored by pigments that are grown in the fiber, such as the naturally colored cottons developed by Sally Fox, or wool made from different colors of sheep. Natural dyes sound eco-friendly but are not necessarily kind to the environment. Almost all natural dyes require the use of chemical mordants; alum is the safest one, but even it is toxic, even fatal if swallowed in quantities as little as one ounce for an adult, and considerably smaller quantities for children. Other mordants greatly expand the range of colors available from natural dyes, and were industrially important before the introduction of modern synthetic dyes, but pose significant problems with toxicity to the dyer and environmental issues. 

Natural dyes themselves are not entirely benign, either, even when you ignore the problem of mordants. Large quantities of natural dyestuffs are required, compared to synthetic dyes; where you need only 5 grams of Procion MX type dye to color a pound of fabric to a medium shade, you may need two or three pounds of a natural dyestuff to obtain a similar color, though the color from most natural dyes will almost never last more than a fraction as long, on fabric that is subjected to regular washing. The amount of land required to grow natural dyestuffs could have surprisingly negative effects, caused by the diversion of land that would otherwise be used to grow food crops or allowed to remain wild, much as we've seen resulting from the use of corn to produce ethanol for fuel. Mud-dyeing would seem to be an ideal alternative, but mud-dyed garments fade to beige after only a few launderings.

A possibly greater problem for the environment is the frequent disposal and replacement of garments. Any garment whose dye fades quickly may be discarded sooner, resulting in a greater cost to the environment when the garment is replaced. Longer lasting dyes, such as fiber reactive dyes, may in fact reduce the cost to the environment if they extend the lifespans of garments dyed with them.

On the whole, it is difficult or impossible to judge whether fiber reactive dyes are any less eco-friendly than any other dye. The most eco-friendly alternative is to wear undyed clothing, but is that really necessary? It would be more useful to buy clothing to last for many years, rather than replacing it when it becomes worn or goes out of fashion, and to redye your own clothing rather than replacing it.

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