Hair Colouring - Is Ammonia Good Or Bad For Our Hair Health

These days, as consumers we are becoming more and more conscious of the ingredients in our beauty products in an attempt to reduce the number of chemicals we expose our bodies to. The hair colouring industry is no exception to this, especially because it typically uses many chemicals in it formulas in order to help us achieve the perfect long-lasting colour. One ingredient in particular that has come under close scrutiny in recent years is Ammonia.

With ’ammonia free’ hair colours rapidly on the rise, we thought we’d take a look into the scientific side of haircare in order to understand how ammonia and ammonia-free products work, and which are the best choices for our hair health.

How Does Hair Colouring Work?

In order to understand how hair colouring works, we must first familiarise ourselves with the PH scale. PH stands for the power of hydrogen, and this scale helps us to judge the acidity/alkalinity of a substance. Our hair naturally sits at a PH level of 4.5-5.5, meaning our hair leans towards the acidic side of the scale. In order for a permanent colour change to take place, our hair needs to become more alkaline- this is where ammonia comes in. Ammonia is a chemical alkalizer gas, which can raise our hairs PH level to 10-10.5. The chemical has a strong, offensive odour, which is a key reason people opt against using it. Once applied to the hair, this then raises the cuticle, allowing the colour formula to penetrate the cortex (the inside of the hair strand). Once the cuticle is lifted, the oxidation process takes place, either lightening the natural hair colour or helping to develop a newly added colour. Without an alkalizer, the chemical process would simply be unable to take place.

“Free From” Hair Colour Products

When a key chemical ingredient is removed from a formula, such as Ammonia, the product's capability is often lost alongside it. Think of it like ‘sugar-free’ products, which have had all of the sugar removed, but to ensure it still tastes the same a sweetener is added in its place. This same rule applies to hair colour, as when ammonia is removed it is replaced with a chemical that does a similar job. The issue the industry is facing is- have we bettered our products by introducing alternatives, or does the old saying ‘if it's not broken don't fix it’ apply?

What Replaces Ammonia in “Ammonia Free” Products?

The most common chemical replacement for ammonia is Monoethanolamine, better known as MEA. MEA is also a chemical alkalizer but rather than a gas, it is a liquid. It has been shown that MEA cannot penetrate the cortex as efficiently as ammonia, which in turn can leave you with an unpredictable colour result, such as a less vibrant finish or in some cases a shorter colour lifespan. In some cases, alcohol is also mixed with MEA as a performance enhancer, meaning just the one replacement chemical has now turned into two. As MEA is a liquid, it does not evaporate once it has served its purpose like ammonia does; it remains on the hair throughout the colour service and requires thorough rinsing to ensure all residue is removed- failure to do so could mean your hair is still oxidising after leaving your hairdresser, resulting in premature colour fading and further damage. MEA isn't all bad, many stylists and clients prefer it due to its subtle odour.

Do Ammonia Free Hair Colouring Products Cause Less Allergic Reactions?

Many people are hesitant to use an ammonia-based hair colour due to a theory that suggests it's the main cause of allergic reactions, however generally speaking it could be any ingredients in the colour formula, or a particular combination of ingredients, as we are all unique, there isn't any way to truly know what could cause an allergic reaction in one person but not in another. All hair colours contain either PPD or PTD, these are the colour molecules that have been used in colour formulas since they were first developed in the 1800s, and are the main reason why it is extremely important to be skin tested. PTD has been found present in some henna formulas, so it's extremely important to know any potential side effects of products that we put on our skin. It is incredibly important when colouring hair that you be tested by your stylist, or you perform a test at home when using a home colourant.

Is Hair Colouring Safe When Pregnant?

Sensitivity can be caused by any chemical, particularly among those of us with sensitive skin or those of us that are pregnant. Although colouring your hair when pregnant is thought to be safe as it does not penetrate the skin, some women have been found to be more sensitive at this time, and you should therefore always consult your midwife before undergoing any type of colour or chemical treatment. Using ammonia that evaporates rather than MEA that sits in the hair throughout the process may be a better option, however, skin testing regularly when you're expecting is important due to hormonal and chemical changes happening constantly in the body.

Are “Ammonia Free” Hair Colouring Products Safer?

Although a harsh chemical, Ammonia penetrates the hair shaft more efficiently overall, which will guarantee you better results and lengthy colour life. To achieve the same job using MEA, up to 6% more of the chemical is required in colourants.

Like all chemicals, ammonia can be damaging if used incorrectly. This is unavoidable, so try not to be misled by marketing phrases such a ‘free from', as there is always an alternative added that is usually equally as damaging or sometimes worse. Regardless of the offensive smell, and the stigma that surrounds the word ‘ammonia’ it’s important to remember, no ammonia does not mean no damage. Both chemicals are harsh and can thin and harden the hair, therefore the only way to avoid this is to give up colouring altogether. Having said this, colouring can be done safely when products are used correctly.

It is very important that after carrying out any chemical treatment, a PH balanced shampoo and conditioner are used- this will ensure your hair is returned to a stable, restored condition and in turn will increase the longevity of your colour.