Breakage After Bleaching

I just started seeing a new colorist, and I’m concerned.

I’ve been having my hair bleached from medium brown to platinum blonde for years, and I usually don’t have much breakage. My last two colorists did really good work.

I started seeing a new colorist in November, after my old stylist moved away. The new stylist used 20 volume peroxide with the bleach, and insisted that my roots were light enough after leaving it on for 30 minutes. My old colorists had always left the bleach on for 60 minutes.

So the new colorist washed out the bleach after just 30 minutes, and it turned out that the roots were too gold. She offered to correct this and scheduled me for another appointment 3 days later. 3 days later, she applied 20 volume to the roots again, leaving it on for 30 minutes.

2 months or so later, I’m noticing that I have a lot of breakage around my face. The hair above my forehead and at my temples is now only about an inch long. I pointed this out to my colorist, and she said the breakage is from bleaching the hair twice. (At the time she bleached it twice in 3 days, she told me it was safe to do that.)

Is there a difference between applying bleach once and leaving it on for 60 minutes, and applying bleach twice and leaving it on for 30 minutes each time?

If this breakage really is from applying the bleach twice, at least I know now to never let anyone do that again. But if it’s from my new colorist’s application technique (maybe she’s overlapping), then my hair is at continued risk for more breakage as long as I keep seeing this colorist. I really can’t have any more breakage; what I have now is bad enough.

The new colorist hadn’t been using a bond builder, something that my old colorist always used. I spoke with my new stylist and told her this, and she says she’ll use a bond builder from now on.

Does it sound like this breakage is likely from applying the bleach twice in 3 days? Or could it be that the new colorist is overlapping? Thanks for any advice.