Eco-Friendly Colors: A Review of Recent Advances in Natural Dyes

1.0 Introduction

One of the most environmentally damaging sectors of the global economy is the textile sector. Given that they are frequently made of toxic compounds that can be damaging to the environment as well as human health, synthetic dyes used in the production of textiles play a significant role in this impact (Asia InCH, 2023; Roy Choudhury, 2014; Selvaraj et al., 2021). The use of natural dyes has drawn more attention as a more environmentally responsible solution in response to these worries. The usage of natural dyes, which are produced from plants, animals, and minerals, dates back thousands of years and is used in several cultures throughout (Kadolph, 2008; Shahid & Mohammad, 2013). Natural dyes offer local communities involved in their manufacturing economic opportunities in addition to reducing the textile industry's negative environmental effects. A little sample of natural dye is shown in Figure 1.

Figure 1.

Various natural dye sources (Asia InCH, 2023)

Natural dyes have been used to colour fabrics for thousands of years and have a lengthy history of use in many different cultural traditions all around the world. Prior to the development of synthetic dyes in the 19th century, natural dyes were the only option for dying fabrics (Ferreira et al., 2004; Mussak & Bechtold, 2009; Tamburini et al., 2020). However, there has been a resurgence in interest in natural dyes in recent years due to growing environmental and health concerns around synthetic dyes. Natural dyes provide a number of advantages over synthetic dyes, such as less of an impact on the environment, the use of renewable resources, and potential health advantages (Saxena & Raja, 2014; Samanta & Konar, 2011). In a number of ways, using natural colours can lessen the environmental effect of textile production. The method of extracting natural dyes is frequently less resource-intensive than the process of creating synthetic dyes, in part because natural dyes are frequently generated from renewable resources such as plants, which may be grown without the use of hazardous chemicals. Last but not least, because natural colours are frequently biodegradable, they do not add to the buildup of dangerous chemicals in the environment (Egan & Salmon, 2022).

Natural dyes have a long history of traditional use, and different civilizations have developed distinctive techniques for extracting and utilising natural colours. For instance, indigo has been used for centuries to dye blue clothes in India and other regions of Asia (Balfour-Paul, 1999). Cochineal insects are used to create a vivid red dye in South America. Many tribes have used natural dyes as a way to show their cultural identity and maintain long-standing customs (Endensor, 2004; Mungmachon, 2012). New and improved natural dyes have been created as a result of recent developments in natural dye research. One illustration is the use of nanotechnology to produce natural dyes with a larger variety of hues and greater durability (Scotter, 2011). New techniques for extracting natural dyes have also been developed by researchers, such as employing enzymes to break down plant fibres and liberate pigment molecules. As a practical substitute for synthetic dyes, these advancements have rekindled interest in natural dyes among manufacturers and designers (Kristensen et al., 2016; Mariotti et al., 2020).

Depending on the raw material, several extraction and processing techniques are employed to create current natural colours. For instance, water, alcohol, or other solvents are frequently used to extract plant-based colours (Prakash et al., 2022). Different extraction techniques, such as boiling the insects that create the pigment, may be necessary for animal-based dyes. After the dye has been removed, it may undergo additional processing to get rid of impurities and intensify the colour (Chu, 2001). When contrasting natural and synthetic colours, it's crucial to take sustainability and environmental impact into account. Although natural dyes are typically seen as more environmentally benign and sustainable than synthetic dyes, there are still some negative effects on the environment related to their manufacture and use (Arora et al., 2017; Handayaniet al., 2018).