Ammonia raises the pH of hair, opening the hair cuticle to allow hair color to penetrate.
Here's a more detailed breakdown of ammonia's effects on hair:
How Ammonia Works in Hair Coloring
Ammonia plays a critical role in the hair coloring process. It's primarily used to:
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Open the Hair Cuticle: Hair has an outer layer called the cuticle, which consists of overlapping scales that protect the inner layers. Ammonia is an alkaline substance that raises the pH of the hair. This causes the cuticle scales to swell and lift, creating openings.
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Allow Color to Penetrate: Once the cuticle is open, the hair dye molecules can enter the cortex, the inner layer of the hair shaft. This is where the permanent color change occurs.
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Facilitate the Oxidation Process: Ammonia also helps activate the peroxide (developer) in the hair dye. This oxidation process is essential for the dye molecules to bond with the hair and create a lasting color.
Potential Effects of Ammonia on Hair
While ammonia is crucial for effective hair coloring, it can also have some potential drawbacks:
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Damage and Dryness: The cuticle’s swelling and lifting can weaken the hair structure over time, leading to dryness, brittleness, and increased susceptibility to damage.
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Fading Color: Repeated use of ammonia can make the hair more porous, causing the color to fade faster.
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Irritation: Ammonia can irritate the scalp and skin, especially in individuals with sensitivities.
Ammonia-Free Alternatives
Due to these potential drawbacks, many hair color products now offer "ammonia-free" formulations. These products typically use alternative alkaline agents, such as:
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Ethanolamine: Often considered a gentler alternative to ammonia, ethanolamine still opens the cuticle but may cause less damage.
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Monoethanolamine (MEA): Another alternative that offers a less harsh method of opening the hair cuticle compared to ammonia.
However, it's important to note that "ammonia-free" does not necessarily mean "damage-free." All chemical hair treatments have the potential to cause some level of damage.
In summary, ammonia in hair dye is an alkaline ingredient that opens the hair cuticle, allowing the dye to penetrate and create lasting color. While effective, it can also lead to potential damage and dryness, leading to the availability of ammonia-free alternatives.
