TOXIC TEXTILES

Use of green dyes instead synthetic dyes

Research revealing that some of the dangerous chemicals used to make children’s clothing and
bedding are absorbed through the skin. The study certainly brought home the benefits of
products made from organic cotton colored with natural dyes, particularly for babies and
children. The research also made me curious about the impact of the textile industry on our
health and the health of the planet. Here’s what I learned.
Textile Chemicals Are Known to Be Bad For Your Health
Many of the chemicals used in textiles are classified by the World Health Organization (WHO)
as moderately to extremely hazardous, and have been associated genetic mutations, cancer,
abnormal hormone levels, birth defects and reproductive problems. Although subjects of most of
these studies were bacteria, wildlife or lab animals, the findings certainly suggest that there is at
least cause for concern and caution.

So we know that our skin can absorb chemicals in our clothing and that many of the chemicals
used in textile production and dangerous. But it’s not just our health that is at risk; the entire
process of textile production is a very dirty business that impacts both person and planet.

How Is Organic Cotton Products Different?

http://organicfamilycircle.com/toxic-textile-industry-why-organically-produced-clothing-
bedding-is-better.html

The textile industry produces and uses approximately 1.3 million tonnes of dyes, pigments and
dye
precursors, valued at around $23 billion, almost all of which is manufactured synthetically.
However, synthetic dyes have some limitations, primarily, (i) their production process requires
hazardous chemicals, creating worker safety concerns, (ii) they may generate hazardous wastes,
and
(iii) these dyes are not environment friendly. This research explores methods where natural dyes
are
produced from plant tissue and fungal species.
Until the second half of the nineteenth century, all dyes used in textiles were naturally derived.
However, with the synthesis of mauveine by Perkin in 1856, the synthetic dye industry has
grown at
a vigorous rate and all but totally eradicated the use of natural dyes. The large number of
synthetic
dyes in use today bears witness to the creativity and innovation of textile chemists in
successfully
satisfying the dyer’s demands for simple, reproducible application processes, and the consumer’s
demand for quality products at a reasonable price. Thus, even though the availability of natural
dyes has been known for centuries, the reasons synthetic dyes have been so popular are:
• They are simple to produce in large quantities,
• They can be manufactured at a reasonable price ($10 – 100/kg),
• They can provide the variety of colors that are demanded by today’s consumers,
• They provide high color-fastness (i.e., the dye is very strongly bound to the fabric and does not
detach after repeated washing cycles).
However, manufacturing of synthetic dyes suffers from the following limitations:
1. Environmentally Unfriendly: The production of synthetic dyes requires strong acids, alkalis,
solvents, high temperatures, and heavy metal catalysts. For example, production of a dye
designated
as Color Index Mordant Blue 23 states, “Treat 4,8-diamino-1,3,5,7-tetrahydroxy-2,6-
anthraquinonedisulfonic acid with boiling alkali or dilute acid and convert to the sodium salt” or
“Treat 1,5-dinitro-anthraquinone with fuming sulfuric acid in the presence of sulfur sufficient to
produce S2O3 at 1300C, hydrolyze with water, and convert to the sodium salt”.
2. Increase in Cost of Feedstock or Energy: Petroleum is the starting material for all synthetic
dyes and
thus the price of dyes is sensitive to the price of petroleum. Also, since synthesis is energy
intensive
(uses super-heated steam, boiling acids, etc.), the process is sensitive to energy prices and also
generates greenhouse gases.
3. Hazardous Waste Generation: Since synthetic production of dyes needs very toxic and
hazardous
chemicals, it also generates a hazardous waste, the disposal of which is a major environmental
and
economic challenge. Moreover, some facilities that produced dyes in the past are now
“Superfund”
sites due to intentional dumping or accidental spills of toxic and hazardous wastes.
4. Increasing Transportation Costs: Since dyes are hazardous materials and are produced at
central
facilities, transportation of dyes from manufacturing plants to textile dyeing and printing
facilities is
a major cost item and a logistic challenge.
5. Toxic and Allergic Reactions: There are occupational safety issues involved since production
processes use the toxic and hazardous materials and conditions described above.
Thus, if bioengineered natural, ‘green’ dyes can be produced at a comparable price, the
following
benefits will be realized:
1. Reduce the use of toxics since starting materials are environmentally benign with associated
benefits in terms of waste disposal and occupational safety.
2. Production can be “decentralized” resulting in savings in transportation costs.
3. After extraction of the dye, the biomass can be used for energy generation (e.g., through
anaerobic treatment to generate methane, which in turn, can be sued as a fuel) and the growth
media can be recycled; thus, there are virtually no wastes generated.
4. Possible beneficial aspects such as higher UV absorption by the fabric (which contains natural
dye) can result in reduced incidence of melanoma.
It is clear, however, that if natural dyes are to be considered as an alternative to the synthetic
dyes
used today, they have to manifest the same characteristics of synthetic dyes as those listed above.
Specifically, the major challenges in this field are:
1. To produce natural dyes in the quantities required,
2. To produce natural dyes at a reasonable price,
3. To produce natural dyes that have high color-fastness.
The major avenues of production of “green” dyes are:
• Extraction from plants
• Extraction from arthropods and marine invertebrates (e.g., sea urchins and starfish)
• Extraction from algae (e.g., blue-green algae)
• Production from bacteria and fungi
The Toxics Use Reduction Institute
University Research in Sustainable Technologies Program