Hair bleaching has long been used to lift or lighten the natural hair color, and it is a procedure that is better to get done at the salon. But not all of us can visit a pro, especially in recent times. So, by putting some effort into researching, you can learn to do it at home.
As most of you who are trying to bleach your hair by yourself are not chemists, there is a lot about the process you may not know. For example, what to do with the leftover bleaching mixture, or can you save the mixed hair bleach for later use? We are about to explain both of these queries.
You can’t save hair bleach after it has been mixed with the developer. The hydrogen peroxide (developer), which activates the bleach powder, gets exhausted within 30 minutes. As a result, the bleach first converts into foam and finally gets dry. However, you can reuse this dry leftover bleach powder by adding a fresh developer.
However, there is one way you can save the bleach and use it even for months. We will get to it in a moment.
Let’s dive a bit deep into what goes on at the back end of the bleaching mixture, making it unable to be stored or saved for later use.
Why Can’t You Save Mixed Hair Bleach?
The hair bleach mixture comprises two parts the bleaching powder and the developer. Both have distinct functions to perform.
- The bleaching powder is alkaline (base) and contains different persulfate salts or ammonia. Its primary function is to open the hair cuticle (outermost layer). However, the salts also support the role of the developer.
- The developer (hydrogen peroxide), which comes in various volumes, performs the oxidation of your natural hair color in a complex chemical process.
When you lighten your hair tint with bleach, you need to mix the bleaching powder and developer beforehand. This mixing activates the powder and produces perfect alkaline conditions that open the hair cuticle and allows the developer to reach the middle layer, where it oxidizes melanin.
There is always a time frame mentioned on the bleach kit in which you have to use the bleach mixture to lighten your hair color. For most parts, the time is less than 30 minutes.
However, if you don’t apply the bleach in the given 20 or 30 minutes, it will lose its action. The hydrogen peroxide will react with bleaching powder, oxidize it completely, and reduce itself. That’s why you can’t save the bleach. A lot of chemistry is involved!
Did you know the developer can damage your hair, especially when used in higher volume on weak and fine hair?
How Can You Save Hair Bleach?
If you read the instructions on the hair bleach kit, you would find that if you have not achieved the color lifting in 30 mins and want to go one or two levels farther in lightening your hair, you first need to rinse out the bleach mixture.
Subsequently, you would need to prepare a fresh blend of developer and bleaching powder and reapply it. Why so? Can’t you leave the already applied mixture for another half an hour?
No, you can’t! The bleach powder and developer mixture remains active for 30 minutes and then loses all of its action. So, if you are to save leftover bleach for later use, it would be unwise because it would have lost its functions after the first 20 to 30 minutes of mixing.
But you can save developer and bleaching powder when they are not mixed!
Therefore, the only way to save bleach is to determine how much you need for your hair. Typically, you would require to mix 2 oz of developer and 1 oz of bleach powder for the average length and volume of female hair.
So, now, you will only take a limited amount of the developer and bleaching powder and can save the remaining for a couple of months.
1. How Long Can You Save Hair Bleaching Powder
Once you have opened the bleaching powder pack that contains ammonia or persulfate salts, you can save and use it for a year. However, you need to make sure that the box is sealed well and kept away from humidity, sunlight, and extreme temperatures.
We suggest you buy those kits of bleaching powder that are enough to use once or twice. Even if you store it properly, it will lose some of its potency and function over time.
2. How Long Opened Bottle of Developer Lasts
The developer or hydrogen peroxide typically comes in a bottle and lasts for less than six months once opened. Keeping the developer sealed is crucial because it dissipates within a few hours if left open in the atmosphere.
Typically, you can save the developer for three months as it loses its efficacy over time, especially when not kept under standard conditions. We suggest you buy a developer that lasts only for two times bleaching your hair.
Can You Use Hair Bleach After Letting It Sit For a Day?
No, you can’t use a hair bleach mixture that has been sitting for one day because hydrogen peroxide would be exhausted within an hour, leaving the dry ammonia behind.
As mentioned earlier, the developer vanishes within a short time if left open in the atmosphere. But when it is mixed with the bleaching powder and left to sit for a day, it will convert the ammonia powder into a foam-like material and get exhausted.
When it gets converted into foam, you should never use bleach because it will not lighten the hair color. Instead, the ammonia in this foam will open the hair cuticle and may cause protein loss from the hair strands, leaving them feeling gummy and damaged.
Can You Reuse Bleach When It Gets Dry
While there is no need to, and you should prefer the fresh powder, you can add developer into it and give it a go when the bleach mixture gets dry.
When your bleach mixture turns dry, it means the developer has got exhausted, leaving behind the ammonia powder. And you can reuse it by adding hydrogen peroxide and preparing a new mixture.
While you can’t and should never save leftover bleach mixture, you can save the ingredients, developer, and bleaching powder, separately for months. If the hydrogen peroxide has been entirely exhausted, leaving dry bleach powder behind, you may add the developer into it and use it again to lighten your hair color. However, it would be best if you prefer fresh ammonia powder.
Using bleach that has turned into foam after sitting for several hours in the bowl can cause protein loss from your hair, leaving it dry, frizzy, and damaged.