Synthetic Versus Natural Dyes - Which Is Better?

Synthetic Versus Natural Dyes - Which Is Better?

As the general consciousness in our society moves to become more eco-friendly and makes more environment-conscious decisions in our everyday behaviors and purchases, we tend to find that there is more damage to the environment being done than was otherwise realized. 

When posed with the question, “which industries are most harmful to the planet?” the first answer for many would be the fossil fuel industry or possibly the animal agriculture industry, but few would say the fashion industry, which makes up 10% of global carbon emissions as of 2019 and is expected to reach 50% by 2030 if current production methods continue.

The harm the fashion industry is causing is undeniable and its destruction is multi-faceted, such as the waste it produces, the microplastics it uses that leach into the oceans, and the toxicity of synthetic dyes. In fact, synthetic dyes are not only harmful to the environment, they are also harmful to humans. 

95% of the wastewater produced by the textile industry come directly from the coloring process and the other 5% comes from the process of rinsing. In synthetic dyes heavy metals such as lead, zinc, and chromium can be found, which, if accumulated in the human body, is carcinogenic. As more and more people learn of this fact, the slow fashion industries in the USA, Europe, and Asia, which push for the use of natural dyes in clothing, grow in both popularity and, thus, production. However, even though these industries are growing, natural dyes still only make up around 1% of the global production.

natural dyes, organic dyes
(Image courtesy Fibre Bio)

Even so, the benefits of producing, and more importantly, purchasing, clothes made with natural dyes cannot be ignored. Firstly, they provide no health hazards to the wearer. Synthetic dyes, as previously mentioned, contain carcinogens, but they can also cause irritation to the skin, whereas natural dyes do exactly the opposite. 

Clothes colored with natural dyes can actually provide UV protection. Some dyes are even antimicrobial, meaning they are able to prevent the growth of microbes in clothing that cause the degradation of the clothing, odor, loss of color, and even skin allergies. Other natural dyes can even keep insects from attacking them, they can keep fleas from the carpet, and moths from the towels. Additionally, colors for these dyes can be easily extracted from a wide range of plants, animals, and insects, all of which can be sourced sustainably and by using only renewable resources. They can even be sourced from the waste by-products of the agriculture and the food and beverage industries, making them even more eco-friendly as they reduce the waste from other industries, which also has the added benefit of being low-cost.  

Though the use of natural dyes seems like a no-brainer and demand for them is growing, it faces many problems and tough competition against its synthetic counterpart. The colors from synthetic dyes are more uniform, whereas colors from natural dyes can vary depending on several factors, such as the type of plant being used, the material being dyed, etc. Natural dyes adhere best to natural fiber like wool, cotton, linen, and silk and have a hard time staying on unnatural fibers, like polyester. Additionally, there are no standard methods or color recipes for people to follow, making the process more complicated, particularly for small businesses. 

The biggest issue facing natural dyes, however, is the use of mordants. Because natural dyes don’t always bond well to fabrics, many who use them have to resort to using metallic mordants to adhere the color to the textile. Mordants help dyes fix onto fabric and prevent the color from fading in the wash or sunlight, but they contain heavy metals, which, of course, are not eco-friendly, and are damaging for human health as well. 

Research had been conducted into finding natural mordants in order to negate the use of the metallic ones. In a 2013 study published in the Journal of Textiles, researchers discussed how they made a mordant using chitosan, which comes from the shells of prawns. In their study they compared their mordant to the industry-standard blue vitriol (CuSO4) and found that, though the metallic mordant was more resistant to washing, both of the mordants performed the same in terms of overall quality of color and resistance to light, perspiration, and rubbing. The only difference in the dyeing process was that the chitosan mordant was used at a 10% and 12% concentration and the blue vitriol only 1% and 2%.

The fashion and textile industry has the capability to be incredibly eco-friendly if it were to find more natural mordants and use natural dyes more often. The waste produced by the natural dye process can be composted, used as biogas, or even animal feed, essentially creating a potentially zero-waste system that satisfies our society’s fashion needs. It will also bring more money to farmers and create safer working environments for those who dye the clothes by not exposing them to the harsh chemicals that the synthetic dyes do. 

Though the natural dye process clearly has room, and need, for improvement, it is still the better option to look and demand for when purchasing textiles, whether it be clothes, linens, towels, carpets, etc. The health, environmental, and social benefits far out-weigh that of the synthetic dyes, whose only benefits are economical and who have already caused immeasurable damage to the environment.

If consumers demand the use of natural dyes along with further research into ways of eliminating the need for metallic mordants, the industry will move in that direction. The simplest rule in economics of supply and demand can be the very thing that improves the sustainability of the textile and fashion industries, and thus protecting the environment from the high amounts of pollution and emissions it is currently experiencing. But unless people are educated on this subject, that change is unlikely to come about anytime soon.