40 Developer With Bleach. If it’s powder bleach, the answer is no. Powder lighteners (bleach) use persulfate salts that lighten the hair far more than hi lift haircolor alone, but can cause extreme damage to hair and scalp. Persulfate salts are not stable in water, so they are only used in powder lightene. Volume 40 is occasionally used to lighten very dark, stubborn hair, as part of the bleaching process.
Volume 40 is not recommended for use on the scalp. Using a 40 volume developer can cause hair damage and chemical burns if not used correctly. Start by putting the bleaching powder in your plastic bowl. Add more little by little and repeat the process until all. First of all, we do not recommend you use 40 vol developer with bleach. If you are using a good quality bleach, (and this includes ugly duckling bleaches of course) it will work and lift very well with 20 or 30 vol developer. For 20 and 30 vol developer, the time taken can vary from 15 minutes up to 30 minutes. If you are using a 40 volume developer, follow the ratio of one part bleach to two parts developer. However, remember that 40 volume developer is very strong and is best used by a professional.