by Angela Cummings and Sophia Ruan Gushée

Let's consider the dyes used in textiles, which are part of our furniture, drapes, carpets, area rugs, bedding, towels, clothes, bags, backpacks, toys, and more.

These dyes can be made of natural and/or synthetic ingredients, but be aware that they can influence indoor air quality and our health.

In this article, we'll explore the advantages and disadvantages of natural and synthetic dyes.

Natural Dyes

Natural dyes are made from plants, animals, or minerals. Nature is the dye source and is often considered less toxic than synthetic dyes. However, that’s not always true.

Canaigre Dock, a desert plant used in dying, can cause pain and swelling when it touches the skin. (1)

Other plants have been identified as toxic when used medicinally, but have not been identified as toxic when used as a dye.

Bloodroot, for example, has been used to dye clothing, stain wood, and as medicine. While it has been classified by the U.S. Department of Agriculture as an unsafe herb for medicinal use, the Department of Agriculture does not address the toxicity of bloodroot as a dye. (2)

Some types of textiles can be dyed by simply dipping the material in the dye. Others require that a mordant be used. (3)

Mordants are water-soluble and create a bond between the dye and fiber. (4) A mordant can be a salt fixative, plant fixative, or mineral fixatives, such as iron, copper, tin, alum, or chrome. (5)  

Of the mineral mordants, the U.S. Department of Agriculture has identified chrome as “highly toxic,” and advises that it not be used for dying. (6)

Synthetic Dyes

Synthetic dyes, made from over 7,000 different color-providing chemicals, were created as a less-expensive, long-lasting alternative to coloring textiles and other materials. (7)(8)

The majority of synthetic dyes are created from coal tar and contain chemicals, like benzene, toluene (9), naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene. (10) These chemicals can contribute to cancer, damage chromosomes (cells) (11), affect the nervous system (brain and nerves), contribute to headaches, dizziness, cognitive impairment, and may include immune, kidney, liver, and reproductive damage. (12)

For synthetic dyes to adhere to a material, heavy metals—like cadmium, cobalt, and antimony trioxide—are often used. (13) These materials can damage the brain and nervous system. (14)

What’s a Better Choice?

Most natural dyes are not harmful to health. The U.S. Department of Agriculture, Natural Resource Conservation Service lists over 50 types of plants in their 2010 publication, “Culturally Significant Plants,” which includes plants used for dying textiles. (15) Of those listed, only three have been identified as toxic.

When deciding between synthetic dyes vs. natural dyes, natural dyes tend to be safer. Consider buying from companies that are conscious of people’s health. This way you’re more likely to buy furniture made with fewer toxins.

References

(1)(4)(6)  USDA – Native Plant Dyes

(2)(15) USDA Culturally Significant Plants

(3)(7) Florida State University – The Synthetic Dye Collection

(5) Pioneer Thinking – Making Natural Dyes from Plants

(8) National Science Foundation – Synthetic Dye

(9)(12) ATSDR- Toluene

(10) ATSDR – Naphthalene, 1-Methylnaphthalene, 2-Methylnaphthalene

(11)(13)(14) A to Z of D-Toxing, Works Cited Part 2