Are natural colorants good for your health?

Abstract

The world has become increasingly aware of environmental issues through discussions about the greenhouse effect, ozone layer depreciation, water pollution and waste disposal. The role of the chemical industry in introducing contaminants into the environment has been much criticised. But how far can this be justified? Brian Glover and Jeff Pierce discuss the issues as seen by one of the world's major colorant manufacturers.

First application of chlorophyll-a as biomordant: sonicator dyeing of wool with betanin dye

“…However, worldwide the use of natural dyes for the colouration of textiles has mainly been confined to craftsman, small scale dyers and printers as well as small scale exporters and producers dealing with high valued ecofriendly textile production and sales (Vankar, 2007). This is especially due to the problem of reproducibility of shades (Türkmen et al, 2004;Glover, 1995). There has been some work carried out to evaluate the textile dyeing with betacyanins dyes (Venkatasubramanian et al, 2009;Mathur and Bhandri, 2001).…”

Effects of Different Mordants on Silk Fabric Dyed with Onion Outer Skin Extracts

“…In some cases the resulting change in shade can be seen as an opportunity to steer color in a wider range. Different types of mordants and their combination on the same natural dye may darken, brighten, or drastically alter the color of the dyemordant solution and influence the shade of the final product [16] which may be a desired effect as well as an unwanted phenomenon [17]. So, final color, its brilliance, and color fastness properties are not only dependent on the dye itself but are also determined by varying concentration and suitable application of mordants.…”

Natural dye–surfactant interactions: thermodynamic and surface parameters

“…The application of non‐allergic, non‐toxic and eco‐friendly dyes, derived from plants and animal sources, on textile fibres has received considerable interest [1–13] as a result of worldwide environmental awareness. A number of commercial dye and textile plants/mills started looking at the possibilities of using natural dye to overcome environmental pollution caused by synthetic dyes [14,15], which almost all have their origin from coal tar and lead to the formation of harmful atmospheric gases. The wastewater has also been found to be polluting the neighbouring areas.…”