PPD, is an organic chemical compound with the formula C6H4(NH2). PPD is a more complex amine system, which may result in intermediates that are less hazardous than the simple aromatic amine system. PPD is a colorless crystalline solid that can oxidize quickly into darker colored compounds once opened or exposed for longer periods of time. PPD can be found in many different products. Many multi-purpose hair dyes, as well as many other cosmetics, currently use PPD, as do some dyes for textiles and leathers. PPD is also used in the production of rubbers, plastics, automotive components and industrial products.
ShoHan Chemical Private Limited (India) is one of the prominent manufacturers of Hair dye intermediates like PPD Paraphenylenediamine, MAP metaminophenol, PAP paraaminophenol (aminophenol), TDS Toluenediamine, RL Resorcinol, Basic dyes- Basic Red, Blue 99 and other critical hair dye intermediates.
ShoHan Chemical Private Limited (India) is one of the few organizations that possess state of the art facility for such critical manufacturing processes
Where is PPD used?
PPD is commonly found in four major industrial uses:
1. Hair Dyes:
• Most permanent hair color formulations contain PPD as one of the active ingredients, especially those colors that are classified as dark. PPD reacts with many other chemicals to achieve its color. As an example, in the case of hair color using PPD, PPD reviews with hydrogen peroxide during the process of oxidation. The PPD and developer, through oxidation, completes the formation of a dye molecule that appears as a color bound into the hair shaft of the person’s hair, and is meant to last for a long time.
2. Dyes for Textiles and Leather.
• PPD is used in dye formulations to dye textiles and leather. PPD can develop different colors as a dye base or react with other chemicals to produce combinations of various dyes.
3. Rubber and Plastics.
• PPD can be used when manufacturing rubber and plastics, as it can modify the properties of the rubber or plastic.
4. Various Industries.
• PPD can be found in other industrial chemicals, such as antioxidants and steel corrosion inhibitors. This indicates that PPD also assists to stabilize products and intermediates.
What is the components of PPD manufacturing?
PPD is made using several steps and simple chemical precursors as fuels. Here is a simple walk through on how it can be made:
1. Starting Material: The most common starting material for making PPD is aniline (C6H5NH2), which is a simple aromatic amine. Aniline is derived from benzene, usually by nitration followed by a reduction reaction.
2. Nitration: The first step normally involves nitrating benzene to make nitrobenzene (C6H5NO2), with a nitro group (-NO2) attached to the benzene ring. To do this, you would react benzene with a nitrating mixture (normally, a strong acid – nitric acid and sulfuric acid).
3. Reduction: After the nitration, you now have nitrobenzene, which is then reduced to an amine by taking the nitro group (-NO2) and making it an amine (-NH2). This will produce phenylenediamine instead (C6H4(NH2)2). Reductions (to make amines) can be accomplished using a reducing agent such as hydrogen gas and normally a catalyst such as palladium on carbon or iron filings in hydrochloric acid.
4. Purification: After making the reduction, crystallization or other separations will need to be performed for purification purposes so that you will have paraphenylenediamine (PPD).
Safety and Concerns
• Allergic Reactions: One of the top concerns with PPD is its potential for allergic reactions, especially when used in hair dyes. Some people may experience contact dermatitis (an inflammation of the skin), while other individuals may experience more severe allergic reactions, e.g. Anaphylaxis. As a result, many hair dye products contain warning labels regarding the potential for allergic reactions, and there are commonly suggestions for users to do a patch test before using a dye product.
• Toxicity: If high amounts of PPD are ingested, inhaled, and/or absorbed, it can also be toxic — this is why safety precautions are adhered to, during its manufacture and use.
Protective Measures:
• Hairdressers and others working with the dyes should take precautions to negate their risk of exposure by using gloves, and appropriate ventilation.