Study of Harmful Chemical (para- phenylenediamine) Effects in Commercial Hair Dyes using TLC (Thin Layer Chromatography) and UV Visible Spectrophotometer: Current Issues and Future Directions (Hair Dyes)

Abstract

Hair dyes are really common, but they can have some not so great stuff in them. Things like phenylenediamine, Resorcinol, ammonia, and heavy metals can be bad for our health. So, we decided to take a closer look at what’s actually in these hair dyes. We used a different methods to test them, like preliminary examination, chemical tests ,and TLC. We also used UV visible spectrophotometry to get a better result. Our goal was to figure out if these hair dyes are really safe for us to use. Commercial hair dyes sample 1a black hair dye,1b brown hair dye, sample 2 Black, sample 3 brown, sample 4a brown ,4b black and sample 5a brown ,5b black were studied. Preliminary examination included Visible inspection, label verification, colour and consistency evaluation, odour assessment. Chemical test were conducted to detect ammonia, hydrogen peroxide, and PPD. Chromatography experiments allowed the separation of individual components, and RF values were determined and compared with scientific literature. UV spectrophotometry further confirmed the presence of multiple chemical components. It turns out that hair dyes made from synthetic materials had Higher RF values, and that’s because they contain less polar compound like PPD . On the other hand, natural henna based dyes had lower RF values due to polar components such as lawsone. When it comes to mixed formulations, they fell somewhere in between. What’s really important to take away from this study is that even hair dyes that claim to be herbal can still contain harmful chemicals. So, it’s crucial for consumers to be aware of what they are using and to carefully analyze the ingredients. This is not just about being mindful of what we put in our hair, but also about being informed about the potential risks associated with certain hair dyes. By being more aware and taking the time to read labels, we can make better choices for our health and well-being.

Introduction

The text presents a study on the chemical analysis and safety assessment of commercial hair dyes, with particular attention to para-phenylenediamine (PPD), a common ingredient in permanent synthetic hair dyes that may cause allergic and other health concerns.

Hair dyes are classified into temporary, semi-permanent, permanent, and natural dyes. Natural henna, derived from Lawsonia inermis, contains lawsone, the compound responsible for its characteristic reddish color, and has traditionally been used for hair coloring and conditioning. In contrast, synthetic dyes may contain chemicals such as PPD, resorcinol, hydrogen peroxide, ammonia, and heavy metals.

Aim and Proposed Work

The study aims to determine the chemical composition and possible presence of harmful substances in selected commercial hair dyes. It proposes the use of:

• Preliminary chemical tests
• Thin-layer chromatography (TLC) for separation and identification
• UV spectrophotometry for studying absorption characteristics
• Comparison with standard/reference values

Methodology

Eight dye samples were examined, including synthetic, semi-permanent, herbal/mixed, and henna-based products. The samples underwent:

• Visual inspection for packaging, labeling, color, and consistency
• Odor evaluation, particularly for chemical/ammonia-like smells
• Solubility testing in water, ethanol, and under heating
• Stability testing over 24–48 hours under light and dark conditions
• Microscopic examination for visible impurities
• Chemical tests, including oxidation with hydrogen peroxide and ferric chloride testing
• TLC analysis using silica gel and a benzene:acetone (8:2) solvent system

Most synthetic samples were insoluble in water at room temperature but became soluble upon heating. The henna-based samples were more readily water-soluble. No obvious foreign particles or impurities were observed microscopically.

TLC Findings

TLC was used to detect PPD by comparing the samples' Rf values with reference values. PPD was detected in most synthetic and mixed formulations:

*The text contains a likely typographical error in one table where Sample 1a is written as 114% instead of approximately 11.4%.

Conclusion

1) Development of Simple and Rapid Detection Methods In the future, this study can be extended to develop simple, quick, and user-friendly methods for detecting harmful chemicals such as Para phenylenediamine in commercial hair dyes. These methods should aim to provide instant results without requiring complex procedures. 2) Design of Paper-Based Detection Systems One possible advancement is the development of paper strip tests, similar to litmus paper, that can instantly indicate the presence of Para-phenylenediamine. Such low cost and easy-to-use tools would be highly beneficial for quick screening and everyday use. 3) Development Detection Kits of Portable Future research can focus on creating portable detection kits that are compact, easy to carry, and simple to operate. These kits could allow consumers to test hair dye products at home without needing specialized knowledge or equipment 4) Advancement in Electronic Detection Devices Advanced studies may lead to the development of small electronic devices, similar to alcohol detectors, that can quickly identify harmful chemicals like Para- phenylenediamine in cosmetic products. Such devices would provide fast and reliable results with improved accuracy. 5) Improvement in Consumer Awareness and Safety These innovations would significantly enhance consumer awareness by enabling individuals to test products before use. This would help reduce health risks associated with exposure to harmful chemicals and promote safer use of cosmetic products. 6) Expansion for Broader Cosmetic Analysis In the future, these detection methods can also be extended to identify other harmful substances present in cosmetics, making the approach more comprehensive and useful for overall product safety evaluation This study evaluates the presence of harmful chemicals in commercial hair dyes, with special focus on Para phenylenediamine using analytical techniques such as Thin Layer Chromatography and UV–Visible Spectrophotometry. The results show that these methods are effective for identifying and estimating the presence of PPD in various hair dye samples. They are also cost effective and easily accessible, making them suitable for routine laboratory analysis. contain The study highlights that most commercially available hair dyes harmful chemicals such as Para phenylenediamine, ammonia, and hydrogen peroxide, which may pose health risks to users. Only a few products, such as pure henna-based dyes, are free from these toxic substances and are comparatively safer for use. However, certain limitations were observed, including interference from other ingredients present in hair dye formulations, limited sensitivity of conventional techniques, and challenges in achieving high specificity. These issues indicate the need for improved analytical methods and better detection approaches.

References

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Copyright

Copyright © 2026 Sadhna Gour, Dr. Mohammad Athar. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.