can left over bleach be used at a later date ?

With bleach, yes you can mix only part of the bleach and keep the rest for a later date - just look at what the measurements are on the box/instructions and half or quarter them as needed i.e. if it says to mix the entire powder pack with the entire bottle of developer then using only half of each will mix up half the bleach.  That said you should never keep bleach that has already been mixed together and any unused mixed bleach should be disposed of. I dont know about box dyes for sure as when I used to use them I always needed the full box but I do recall them saying that any unused mixture should be discarded so it seems similar to bleach in that once its been mixed you need to use it there and then.

The semi perm hair dyes we sell have a use within 12 months after opening time but as many posters on here will confirm they can be ok long after this as long as they are closed and kept away from extreme heat/cold, sunlight etc.  The actual shelf life (un-opened) is at least 30 months from date of manufacture however the longer a dye is left unused the more the colour can change or separate so shake/mix the dye well before using if its been standing a long time and also try a strand test first.  Just thought I should mention that incase you or other readers only kept the dyes for a max of 12 months as they may be fine long after this :).

Hope this helps.

Once you mix bleach you have to use it straight away or else "bin it". If, as Nickki says, you can mix part of the peroxide/powder and keep the rest of the unmixed stuff for a few months afterwards. If you have a box bleach (XXL Ice Blonde for example) you have no choice but to mix the whole thing so you have to chuck out what you don't use.

Jerome Russel bleaches are ones that you mix but make sure you measure out what you're mixing so you don't have too much of one or the other going into the mix. That way whatever you save afterwards is also the right amount to be mixed. For example use exactly half of the cream and half of the powder then you have two exact halves left over for next time etc.

lots of thanks to you both !!!! i do use jerome russell for streaks and although its not expensive it will certainly last longer using half the amount.just got some ice blonde as recommended by you mathurine in another post,gonna do my whole head and later apply atomic turquiose,electric banana,nuclear red and napalm orange !!!! thanks to you and nikki again !!!!! x

To keep bleach lightening powder store sealed bag in tight lid tin out of direct sun light.It will however eventually go off.
keep all direction for future mixing ratio timing ect! Mike B2MR

It will however eventually go off.

I can confirm that too - before I set up Beeunique and did not bleach my hair that often I used some bleach powder I had had for years and it mixed up to this weird gloopy lumpy mess and was awful.  I tried it on my hair anyway but it went all flakey and crumbly almost straight away and lightened my hair about a tenth of what I would normally get from bleach of that strength so I too would say its fine to leave un-mixed bleach but don't leave it for too long (months should be fine but years may be another matter).

Experience teaches us all i too have tried using an old batch i knew the colour had changed i knew that it seemed a tad lumpy and it did not mix correctly. but yes went ahead and used it and ye sit came back to haunt me! i got about 1to 2 levels of lift and yes had to re do!! my lesson get rid of old stuff if it does not look smell or mix correctly then it's toast.
Mike B2MR

thanks again nikki !!!! thanks mikeb2mr !!!! always good hints,tips and advice on here as always !!!! super speedy delivery from bee unique too !!!!! simply the best ;D  😀  ;D !!!!!!!!!! x

Thanks, thats a great thing to hear on a Monday morning, made my day - cheers 😀

If you leave peroxide in direct sunlight the bottles can burst, so make sure you keep it somewhere dark and cool or you will have a lot of mess to clear up!!

Mixed bleach expands with heat which is why the bottles burst. Being the nerd I am I've actually put a small amount on a plate in the sunlight and watched it, while I was waiting for the bleach on my hair to do it's work. 😀 It's weird stuff!

Btw, if you're throwing away old bleach it's for that reason that you need to leave the lid off the container that you're throwing away. Otherwise it'll burst in the bin and the smell is something you don't need. If it bursts through the bin bag then the clean up could be nasty too!