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How Long Should You Leave 30 Volume Bleach in Your Hair?

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Looking for a drastic hair change? Using 30 volume developer and bleach is one of the most efficient ways to lighten up your dark natural curls.

While 30 volume bleach will lighten your hair up quickly, it’s so important not to leave it in too long. In this article, we’ll share with you how long you should leave 30 volume bleach in your hair. Let’s get into it!

How Long Should You Leave 30 Volume Bleach in Your Hair 

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You should leave 30 volume bleach in your hair for no longer than 15 to 30 minutes. The exact amount of time depends on your natural hair color and your desired result. 

For instance, if you have brown hair and want to lighten it a bit, fifteen minutes will more than likely be enough. However, the process becomes more complicated if your hair is very dark and you want blonde hair.

In this case, do not leave the bleach in your hair for more than 30 minutes.

If you’re using a DIY hair dye kit at home, read the instructions on the packaging. For some kits, the instructions will recommend leaving the bleach for no longer than 25 minutes. 

The Difference Between Hair Volume Developer Strengths 

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To understand the difference between hair developer levels, we’ll start with the basics. The developer is a chemical that opens up your hair’s cuticle when mixed with hair color or bleach.

It contains hydrogen peroxide, which is indicated by the number on the developer packaging (10, 20, 30, or 40). Let’s learn more about developer strengths below.

  • 10 volume developer is perfect if you’re trying to darken your hair by one level. Due to its low peroxide level (3%), 10 volume developer-only adds a tint or shade of the same lightness level as your base color. Thus, it is perfect to go from a lighter to a darker shade or a no-lift hair color. 
  • 20 volume developer is mainly used with permanent dye or temporary color. Its peroxide level (6%) makes it perfect for covering 100% of gray or white hair with a beautiful, long-lasting color, unlike 10 volume developer, it opens the hair cuticle and lightens the hair by one to two levels. 
  • 30 volume developer is similar to the 20 volume developer; however, it lightens the hair’s original color by two or three levels due to its higher peroxide level (9%). It’s a good choice if your desired hair color is no more than two or three levels lighter than your original hair color. Thus, the ’30 volume developer’ is your best option if your hair is dark and you want light brown to honey blonde curls. 
  • 40 volume developer is the strongest of all developers and can drastically alter the color of your hair. With its high peroxide level (12%), 40 volume developer can lighten your hair up to four shades. 

Warning: We recommend only using 40 volume developer under the guidance of a colorist, as it may have detrimental effects on your hair strands.  

Does 30 Volume Damage Hair? 

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Any hair developer will cause some level of damage to your hair cuticles, but luckily, there are several ways to minimize this hair damage and preserve your natural curls.

It is crucial to prepare your curls before bleaching to avoid severe damage:

  • Two weeks before bleaching, apply moisturizing hair masks at least twice a week for intensive nourishment. 
  • Apply organic coconut oil to your curls the night before bleaching your hair. Cover your hair in a shower cap and wear it overnight. Don’t rinse the oil out. Coconut oil forms a natural barrier between the developer and hair fiber and helps to prevent protein loss. Don’t worry; it won’t affect the final result. 
  • Lay off the heat styling tools and any high manipulation hairstyles before bleaching your hair.

How to Safely Use 30 Volume Developer

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If you’re wondering about the safest way to use 30 volume developer on your curly hair, this is the section for you. We’ll go through the entire process step-by-step to help you get your desired result without ruining your hair.  

Prep Your Curls

The first step is to prep your curls for bleaching. Divide your hair into eight sections. Detangle each section with a wide-toothed comb, divide it in two, and twist it to the ends.

This step will help stretch out your curls and make the coloring process more manageable. If you have very short hair, then this step is unnecessary.

Apply petroleum jelly or oil (coconut or olive) to your hairline and the tops of your ears to protect your skin from the bleach mixture. 

Read this article to learn how to use coconut oil before bleaching your hair following a detailed step-by-step.

Mix the Bleach and Developer

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With gloved hands, add the bleach powder and developer to a plastic bowl. You can buy these two products separately or as one kit.

Always make sure that both are from the same brand since different brands may require different mixing and coloring steps.

In most cases, you will need to follow a 1:1, 1:2, or 1:3 ratio (bleach to developer). The 1:2 ratio is the standard measurement for bleaching curls – 1 part bleach and 2 parts developer.

It will create a thick mixture that’s not too messy and relatively easy to apply evenly. If you’re not sure how much developer and bleach to use, look at the instructions on the product packaging or contact a colorist. 

Ensure that you have enough of the bleach mixture to cover all of your hair. Four ounces of the developer should be an adequate amount for shoulder-length curls.

Mix the bleach and developer thoroughly until there are no bleach chunks – it should have the consistency of pancake batter. 

Apply the Bleach Mixture

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  • Choose a section in the back and undo the twist. Apply the bleach to your hair using a tinting brush starting 1/2 inch away from the roots. Twist the section up again and repeat the process for all of the other sections. Be careful not to miss any spots. 
  • Don’t leave the bleach in your hair too long, even if the color is not light enough. Leave the bleach in according to the recommended time (15-30 minutes or the amount of time listed on the packaging).
  • Check your results every 5-10 minutes by wiping off a tiny bit of bleach and looking at your hair. If it lightens up enough before 15 minutes have passed, you can rinse it out early.
  • Alternatively you can go through the entire process with a test strand to determine exactly how to leave bleach the in your hair. 30 volume developer can be very damaging when left in for too long.
  • Wash your hair with a neutralizing shampoo and then deep condition it to replenish some of the moisture lost during the bleaching process. You might need to bleach your hair again if you didn’t get the lift you were looking for. It’s best to wait at least 3-4 days before repeating the process. 
  • Completing the process multiple times in an effort to achieve a lighten hair colors isn’t recommended.
  • Don’t worry if your hair turns out orange. This is nothing that a good toner can’t fix. Please read the instructions carefully before applying them to your hair.

Your hair may feel dry after bleaching it. Keep your curls moisturized by doing weekly deep conditioning treatments. 

Is 30 Volume Developer Bad for Your Hair?

The chemicals used within 30 volume develop aren’t “good” for your hair. Bleaching sessions won’t automatically destroy your hair and leave you bald, but it’s critical that you know how long to leave bleach in your hair.

Frequently Asked Questions

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Should I Use 30 or 40 Volume Bleach?

If your desired hair color is not more than two to three shades lighter than your natural color, you should use a 30 volume developer. The strongest developer, 40 volume developer, can dramatically alter your hair’s color and cause permanent damage if used incorrectly. Only use 40 volume developers with the help of a colorist.

Is 30 or 40 Volume Bleach Stronger?

40 volume developers are stronger than 30 volume developers. The larger the number (i.e., 40 is greater than 30), the stronger the developer. For example, 30 volume developer is stronger than 20 volume developer. Although, 40 volume developers should only be used with a colorist and not when you’re doing your hair at home. It can easily damage your hair and scalp (regardless of hair type) without the guidance of a professional.

Can I Lighten My Hair With 30 Volume Developer?

A peroxide level of 9% makes 30 volume developers lighten the hair’s natural color by about two to three levels. This is a great choice if you want your hair to be no lighter than a couple of shades on the color wheel.

How Much Bleach Do You Mix With 30 Developer?

You should always mix the ratio of developer and bleach in your hair lightener 2:1, no matter what volume of developer you use. For example, if you use a 30 volume developer, you will need to mix it with bleach at a ratio of 2:1. There are two exceptions to this rule: (1) you always follow the instructions on the product packaging, and (2) if you’re working with a hair colorist, you should always follow their instructions.

Can You Leave Bleach on for an Hour?

You shouldn’t leave the bleach on your hair for 60 minutes unless you’re working with a professional hair colorist. Even when you’re working with a professional leaving bleach on your hair for longer than 30 minutes could lead to significant hair damage.


If you follow the instructions in this article and consult a colorist (or a hairdresser) when you’re unsure, you could end up with a stunning result! 

Although, please don’t leave bleach in your hair too long to help preserve your hair strands. As a general rule, it’s important to follow the instructions specifically listed on the product’s packaging.

We must emphasize that if you choose to bleach your hair at home, it is best to use a lower-level developer and never rush the process.

Curly hair is the most vulnerable hair type of them all. So, lifting your curls gradually is key to preserving the natural texture and health of your hair.