How to Bleach Hair
If you have dark hair and wish to dye it blonde, you need to be able to use bleach. However, hair bleach is a powerful product capable of dramatically changing the appearance of your hair, and with that power comes the potential for some pretty devastating results if used incorrectly.
Uneven lightening, brittle hair, and unintended hair color results like red or yellow are just a fraction of what could happen if you use the product haphazardly, but a little knowledge goes a long way and with the tips and tools in this article, you'll be bleaching your hair with finesse before you know it.
How Bleach Works
Hair bleach consists of two different products that are mixed together before use:
- Bleach powder - which consists of lighteners, thickeners, and alkalizing agents, among other compounds
- Developer - which is a solution of hydrogen peroxide
It's worth noting that both the powder itself and the developer are lighteners, but it's the combination that is particularly special because combining them allows for two vital functions: the powder becomes moist, making chemical reactions occur more readily, and the alkalizing agents activate the developer, causing it to start oxidizing whatever it contacts.
This whole process becomes even more ingenious when you consider how it affects the hair's structure though. Plain hydrogen peroxide can lighten hair on its own, but the effect is surprisingly mild. It also isn't able to penetrate the hair very effectively due to the cuticles of the hair shaft sealing against environmental stressors. However, a little alkalinity from the mixed hair bleach not only activates the peroxide, it also happens to open the cuticle layer, allowing the bleach to enter the cortex of the hair shaft where it oxidizes melanin pigment that forms your natural hair color.
Now that you know a little about how hair bleach works, it's important to discuss the individual components of the product. Developer in particular is very important to understand because it comes in different strengths and this changes how strong the mixed product will be. The strengths, while often measured in percentages, are more commonly known as the developer volume.
Permanent dyes, bleach, bleach baths
Permanent dyes, bleach, bleach baths
Permanent dyes, bleach (generally off-scalp*)
High lift dye, some permanent dyes, very rarely in off-scalp bleaching*
*on-scalp and off-scalp bleaching will be explained later into this article, as will maximum developer explained on a per-brand basis
Using the table above will give you a rough idea of the uses of each developer volume as it pertains to the whole of hair coloring, both lightening and dyeing hair. Most important to grasp though, is that in almost all cases, a higher developer volume will produce more lightening in a given time-frame, at the expense of also causing more irritation to the scalp and potentially more damage.
There are also brand-dependent differences which will be discussed later, where you may be able to use 30 vol developer on-scalp with one bleach powder, but another it either won't be recommended, or is even advised against. There are reasons for this that are due to the formula of the hair bleach, making it important to understand the individual product you've chosen in the context of more generalized rules.
Hair Levels and Tones
All hair from black to the lightest blonde falls somewhere on the international color code (ICC) level system. Black hair is defined as level one usually, and this goes all the way to level ten, which is a practically white shade of blonde. There is some variation among how different brands use the level scale though, but these are typically small and few rather than overly detrimental differences.
Now that you know how the darkness of your hair is categorized, it's helpful to the process of bleaching itself to discuss just what comprises its depth. The color of your natural hair consists of a base pigment underneath the color you actually see, and this contributes to that depth of the color, making it appear dark. In blonde hair, this base pigment is anything from pale yellow to golden orange. Black hair, however, has a deep, dark red base.
When you bleach your hair, the visible color is stripped away to reveal the base pigment and you can estimate how much lightening has occurred by looking at the base color you've arrived at. You can also use the base color as a guide to what level of toner you should be using, and what color you will ultimately be able to reach after toning is complete.
As an example of how you would go about using this information, if you have identified that your current hair color is a level five, and you can lift it up to three levels reliably with the bleach you've prepared, the lightest level you can reach is an eight. You can then see that your hair became a dark yellow color which tells you this is correct. Now that you know what level you've reached, you know that you need an ash toner that is a level eight or nine in order to neutralize this yellow pigment to a natural blonde color.
Essentially, the chart below is your go-to cheat sheet for reaching any new hair color. It gives you the knowledge you need to know whether a goal is reasonable (in conjunction with knowledge of developer volume), and even what to look for to know you're on the right track, as well as the correct shade of dye to be used as a toner afterwards to finish your new hair color!
Lift Potential of Bleach
A number of factors impact the effectiveness of a product when bleaching hair. Some of the more major factors include:
- Hair porosity - how receptive your hair is to soaking up color in dyes. Porous hair bleaches more readily a lot of the time because the product has an easier time getting inside the hair due to weakened cuticles. The opposite situation is resistant hair, which is, as implied, more resistant to bleaching.
- Developer volume - has a fairly linear effect on hair bleaching, higher volume equals more lightening.
- Bleach powder - the particular bleach powder you choose to use can dramatically affect how much lightening you're able to achieve. For example, there's a significant difference between a powder with boosters or a plain generic powder.
- Warmth - the warmer the temperature of the bleach, the more readily it reacts with your hair. This often leads to hair wraps or hoods being used on rather dark hair or where additional lightening is desired.
- Water quality - interestingly enough, the quality of water you regularly wash your hair with has an effect on hair bleach. Water higher in metals like iron or copper leads to those metals being found in your hair in higher than expected concentrations and can actually catalyze the bleach, making it react more rapidly and aggressively. Sometimes a chelating shampoo is used beforehand if this is known to be a potential issue.
1 - 2 levels
2 - 3 levels
3 - 4 levels
Should You Use Bleach?
Before you even start using bleach, decide whether you will actually require it, whether it is the best tool for the job, and other factors like the condition of your hair. As much as you might want a new lighter hair color for example, there's only so much damage your hair can take. Depending on how coarse your hair strands are, this is more than you'd expect, but you'll still notice a deterioration of its appearance even before any snapping occurs, so it's important to be mindful of your hair's health before using the product.
Other factors to consider include:
- How many levels do you want to lighten your hair by?
- Has your hair been dyed before?
For a new color that requires 2 - 3 levels of lightening, you'll generally be able to achieve this result using dye with 30 or 40 vol depending on initial depth and whether your hair has been dyed before. Hair that hasn't been dyed before is commonly referred to as virgin hair and this will be lightened by permanent dye with a high volume of developer.
Hair that has already dyed will be significantly more stubborn however, necessitating the use of other products like hair dye remover, bleach, or a bleach bath dependent on how much lighter you need to take it. That however, is somewhat outside the scope of this article as its more in the territory of color correction.
Basically, consider natural hair a good candidate for lightening by dye if you only need 2 - 3 levels of lift. For significant lightening, very dark, or dyed hair, bleaching is generally necessary.
Generic VS Salon Hair Bleach
There's two different kinds of bleach to consider and your choice will come down to some combination of budget and desired results. Generic products work just fine, but the problem with them is that you get less lightening out of them compared to some of the high-end brands that include boosters and damage-mitigating ingredients that allow the bleach to lighten more effectively from a lower volume of developer. Products like Igora Rapid Blonde or Wella Blondor with 20 vol developer, for example, can usually out-perform a generic powder with 30 vol developer.
To be frank, when it comes to the condition of your hair I'd recommend spending a little more on a better product because it will also lighten more effectively, but there's no real issue to going with the cheaper powders, just understand that depending on how dark your hair is and how much lift you need, you may have to bleach twice with one of those powders, or with a higher developer volume/longer duration.
Preparing Hair Bleach
You should have a goal in mind before bleaching your hair. By combining the concept of depth levels and the lifting potential of the different peroxide concentrations, you should arrive at an estimate of how much lift you can achieve when bleaching your hair, and this will help you avoid mistakes and not hold unrealistic expectations when you use the product. There is of course some brand variation here, and often a product will state how much lift you can hope for from a specific volume of developer.
To prepare the bleach, you will need a standard hair dye mixing bowl and tinting brush. Mix the powder together in a one to one ratio of bleach and your chosen concentration of peroxide, unless the brand you're using specifies a different ratio. The product should be prepared and then used immediately as there is a chemical reaction taking place and the product is losing effectiveness while you leave it sitting.
Always use gloves even when only mixing the bleach. Whilst it won't do anything to most people if a little gets on your hands and isn't left too long, some people have more sensitive skin than others and it's just good practice to protect your hands in general when using any chemical product.
When applying bleach, a quicker application will reduce the chance of uneven results. In order to apply it quickly, there's a number of different sectioning and application methods that can be used, often based on personal preference. The simplest and most reliable for most people would be to divide the hair into four quadrants though.
- To divide your hair into quadrants, all you need to do is part it both down the middle and again from ear to ear. Aim to get these quadrant sections roughly even. There is a bit of practice involved but the general positions above are a good guideline to work from, adjust based on individual head shape as needed. For long or very thick hair, you may wish to use crocodile sectioning clips rather than a flat clip.
- Once you have your four quadrants, all you need to do now is work on them one at a time, quickly, taking relatively thin sections of hair from top to bottom, painting with bleach from close to the root of the hair, out along the lengths and tips.
- Apply less bleach very close to the scalp. This is for two reasons: it will cause less skin irritation, and it mitigates the risk of 'hot roots', where the heat of the scalp has lead to more bleaching closer to the scalp. Don't worry, the moistness of the product will allow it to creep in all the way and coat the root area properly, though less densely than if you put it there by brush. Alternatively if you lack the time or are having trouble not covering the roots too much, wrap the whole thing after coating all hair and then it's a non-issue because the heat will be equalized.
- As mentioned above, you can choose to wrap your hair at the end and this will lead to more lightening because the entire preparation is kept warmer. Some brands advise against this, so consider it relative to your brand. Generally the more aggressive powders are the products you shouldn't wrap.
On-Scalp and Off-Scalp Bleaching
As mentioned earlier in this article, there's a distinction to be made about whether the hair bleach you are using contacts the scalp or not. Generally this pertains to highlights, which are painted into foil sheets and the product is intentionally kept a distance away from the root section. This primarily allows for a higher developer volume to be used while bleaching.
You can get away with doing this in highlights because you're working with less of the hair and the product won't contact the skin much if at all, limiting irritation. You should still only use the higher concentration of peroxide if the manufacturer allows it and you truly need the extra power though.
That power comes with a price in that it causes higher damage. This damage will be less visible because it only affects a small part of the hair compared to a full head bleach, but with repeated applications of highlights over time, it can and does add up.
The length of time that you leave the bleach in to process is largely dependent on your goal. The only thing to remember is that it shouldn't be left in for longer than 45 minutes in most cases and for most brands. If the bleach hasn't lifted enough pigment by that time you will have to perform another application or follow up with a lightening dye, and this shouldn't be done for at least a week. It also should only be repeated if your hair is still in good condition.
There's three primary reasons why you need to rinse the bleach out in a certain time-frame or less, dependent on brand used: effectiveness, damage, and irritation. The reaction allowing bleach to lighten hair actually slows down quite suddenly, just like it ramps up quite suddenly after application. This is because most of the reactive oxygen has already been liberated by this point.
If you were to keep the bleach in your hair longer than recommended, all you really do is increase irritation to your scalp and cause more damage to your hair because the hair has been kept in an alkaline state that weakens it structurally over time and makes it more susceptible to damage the longer the bleach is left in. It is not only the oxidation that damages your hair, but also the increased pH and moist environment.
If the bleach has lifted enough pigment before the recommended maximum time-frame however, wash it out immediately to stop the process and avoid any further damage or lightening. Bleach needs to be watched closely to avoid over-processing, and you should check it roughly every 5 - 10 minutes as it processes.
Rinsing and Toning
Bleach should be rinsed out thoroughly with plenty of cool water before you shampoo your hair. Any bleach that isn't rinsed out will potentially continue to damage your hair, as well as irritate your skin, so it is important that you ensure it is all removed. Shampoo your hair twice to remove any remaining residue.
If you're going to be applying a dye or toner immediately, avoid using conditioner because it closes the hair cuticles and will reduce how effectively the dye is able to penetrate and neutralize any unwanted colors that are present. This is a generalization, but will work for most people, the dye you use to tone your hair is 1 - 2 levels lighter than the level you bleached it too, in an ash tone.
For example, if you bleached your hair to level 6 and it was a deep golden orange, you would use a 7A or 8A to tone it. If you bleached your hair to a level 8 and it was yellow, you would use a 9A or 10A to tone it.The dye will be suited to the base tone of your hair because of the level that was chosen so in the darker example it's a darker dye and contains mostly blue pigment to cope with orange tones, whereas the lighter example is violet.
The only time this won't work is if you're bleaching previously dyed hair and it has continued to look orange into lighter levels than it should due to the artificial pigment present. This is technically a color correction at this point and to give some insight without digressing too much, the proper way to solve it would be to take a lighter dye and add straight ash or a sensible, small amount of a pure blue tone if the brand used has that.
After toning, rinse the product out and then you can follow up with conditioner to neutralize any lingering alkalinity and seal the color into the hair. For hair that feels really rough, you can mix a small amount of white vinegar into some conditioner too and this is an effective way to close the cuticles and bring the hair back to natural balance much quicker. This will help make your hair feel smoother and look shinier, as well as decrease fading of the new hair color.
Bleaching doesn't have to end in a horror story, nor does it have to damage your hair. To achieve the best results and maintain the integrity of your hair, remember to be safe when you use it, and to only apply it to hair that isn't already damaged. If you look after your hair like this, it will thank you by looking its best every day.
- How to Take Care of Dyed Hair
Colored hair requires care to keep it looking good and prevent the shade from fading. Find out how to look after your new color.
- How to Tone Blonde Hair
Bleached hair looks its best when it's toned. Find out how to properly tone your hair to achieve a beautiful natural color.
- How to Dye Hair Blonde
Wishing you were blonde? Find out how to dye your hair blonde - the right way!
Do you have a question about bleach, or need more help using it? Leave a comment for tailored advice...
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2014 Maffew James