460 Preventing and Reducing Harm from Toxics
Dyeing
Many dyes are made with heavy metals and other toxic chemicals. The waste
from making dyes is often poured into waterways, filling them with pollutants
that are dangerous and difficult to clean up.
How to reduce pollution
Small businesses in the dye industry can reduce harmful waste by following
these guidelines:
• Avoid the most toxic dyes, such as azo dyes, and look for safer alternatives.
Azo dyes, known to cause birth defects, are commonly used in printing,
textiles, paper manufacturing, pharmaceuticals, and food industries.
• Control the amount of toxics used.
• Reuse byproducts from dyeing as materials to make other products.
• Reuse cleaning water to make the next batch of dye.
• Use high-pressure hoses for cleaning to reduce the amount of wastewater.
• Label and store toxic materials in secure areas away from waterways.
Tanneries
Leather tanneries use large amounts of water, salts, and toxic chemicals,
such as different forms of chromium. At the end of the tanning process,
these chemicals are often dumped as waste into rivers and other waterways.
As a result, communities around tanneries often have highly contaminated
drinking water.
In the short term, these toxics can cause bronchitis, asthma, and other
breathing problems. In the long term, repeated exposures can cause birth
defects and cancers.
How to reduce pollution
Some tanneries use nontoxic or less toxic production methods. Traditional
methods of tanning use animal parts for safer and cleaner tanning. For
tanneries that use chromium, there are ways to recover and recycle chromium
so that less is used, and less ends up as waste. This reduces costs as well as
toxic pollution. The water used in tanning baths can be recycled, and the
wastewater can be treated to make it safer before dumping.
A Community Guide to Environmental Health 2012