Low impact dyes do not contain toxic chemicals or mordants (which fix the dye to the fabric), require less rinsing and have a high absorption rate in the fabric (~70%), according to OekoTex.

Low impact dyes that meet the above definition are classified by the Oeko-Tex Standard 100 as eco-friendly.

Most dyes require water and energy during the dyeing process. Most dyes also need auxiliary chemicals such as salt, soda ash, acids, leveling agents etc. to work effectively. Different dyes and different fabrics dictates the necessary auxiliary chemicals needed in the dyeing process.

As pollution in the textile industry has come under more scrutiny, chemical companies, brands and manufacturers have been innovating and marketing through a sustainability lens.

Dyeing has an enormous impact on the overall environmental footprint of textile manufacturing.

Let’s break down the definition into four different sections to fully understand what low impact dyes are, and how their use results in less pollution when compared to their conventional counterparts.

Dye toxicity

The toxicity of a dye considers the structure of the dye rather than the dyeing process. The following dyes do NOT qualify as low impact dyes.

• Those that contain heavy metals and carcinogens.
• Dyes that cause allergic reactions.

Dyes that pass eco-standards such as bluesign, GOTS, OekoTex 100 and Cradle to Cradle, and are compliant to the ZDHC MRSL have been assessed for toxicity and should be chosen over dyes that have not.

Dye manufacturers will tell their suppliers if their dyes pass these standards.

Resources. Water and energy in the dyeing process

Processing textiles requires lots of water and energy to heat the water. Most dyes dissolve in hot water to make a dye-bath. Fabric and auxiliary chemicals are added, and during the dyeing process the dye is fixed onto the fabric. A high quality, level dyeing is achieved by using heat, chemicals, time and agitation.

Washing, bleaching and preparing the fabric for dyeing requires water as does cleaning and rinsing the fabric after the dyeing step.

Low impact dyes work with much less water, require less rinsing and often work at lower temperatures.

Reducing water and energy has a positive impact on the bottom line and a significantly lower environmental footprint.

Auxiliary chemical loading

Dyes work under certain conditions that are achieved by using chemicals and temperature. For example, reactive dyes need salt to attract them to the cotton substrate and alkali to fix them permanently onto the fabric. Leveling agents and wetting agents are present during dyeing to achieve a high quality product. Blotchy fabrics that bleed and fade quickly are undesirable.

Low impact dyes work with significantly fewer auxiliary chemicals such as salt and alkali.

Many auxiliary chemicals negatively impact water effluent, because of the large amount needed during the dyeing process. High salinity at a high pH is not good for fresh water ecosystems.

Absorption rates (waste)

One of the problems with dyeing is that not all of the dye reacts with the textile, which means that a lot of unreacted dyestuff goes down the drain in the form of waste. In some cases only 50 to 70% of the dye actually stays on the fabric.

Low impact dyes have high absorption rates, meaning that 80 to 90% of the dye remains on the fabric.

By working with high quality dyes made by chemical companies that focus on sustainability, there are plenty of low impact dyes available in the marketplace today.

What are the impacts to your business?

Questions to consider:

• Could low impact dyes be part of your sustainability strategy?
• Do your suppliers focus in reducing their environmental footprint?

For help with any issue associated with chemicals or sustainability, contact Amanda Cattermole at (415) 412 8406 or Amanda@cattermoleconsulting.com. We can help you develop powerful solutions to protect your company and brand reputation that result in safer products manufactured in cleaner supply chains.

Tips and Insights contains information to help you make informed chemical management decisions. Each post highlights a particular topic and includes questions you may want to consider for your business.