It is unfortunate that bleach has gotten such a bad reputation over the years. While bleaching the hair can be damaging in the hands of an untrained stylist, when performed correctly it is the only way to achieve certain haircolor results. When performed by an experienced stylist, bleaching the hair is no more damaging than any other chemical service, such as perming or chemically straightening the hair.
What is so great about bleach? Well, it is the only way to lighten dark haircolor in order to achieve ultra-light and platinum blondes. While permanent hair dye has the ability to lighten hair a few shades, it is simply inadequate when it comes to going from dark to light. Also, permanent hair dye only has the ability to lighten virgin hair, or hair that has never been chemically processed. For example, hair that has been dyed brown can only be made blonde with the use of bleach. Simply putting a blonde shade of dye on hair that has been dyed brown will have absolutely no effect on the hair.
The reason why bleach has gained a reputation for damaging the hair is because most stylists do not understand how to mix a bleach formula. Although there are several different types of bleach, the most popular bleach for salon use is powdered bleach. This powder must be mixed with a hydrogen peroxide developer in order to lighten hair. Developer comes in different strengths, based on the oxygen content of the developer. There are four popular “strengths” of developer: 10 volume, 20 volume, 30 volume, and 40 volume. Of these formulas, 10 volume has the lowest oxygen content and 40 volume has the highest.
This is where most hairstylists make mistakes. They assume that 40 volume developer is “stronger” and that 10 volume developer is “weaker”. This, however, is a common fallacy, even among experienced stylists. The truth is that 10 volume developer isn’t any stronger or weaker than a 40 volume developer; it just takes longer for a 10 volume developer and bleach mixture to lighten the hair because of the reduced oxygen content. As a result, most stylists mix powdered bleach with 30 or 40 volume developer in the misguided belief that they will be able to achieve a lighter result.
The truth is that 10 or 20 volume developer will lighten hair just as much as a 30 or 40 volume developer, it just takes more time. The damage to the hair occurs when this process is speeded up with the use of heat or a high-volume developer. In other words, the faster the hair is lightened, the more damage that will occur. When a client with black hair wants to become a blonde, many stylists will automatically mix powdered bleach with 30 or 40 volume developer and then stick the client under a heated dryer. While this method will quickly lighten hair, it will also cause irreparable damage. On the other hand, if the stylist had mixed the bleach with a 20 volume developer and processed the client’s hair at room temperature, it would take longer to get to blonde, but the hair would be much healthier as a result.