Disposing of natural dye baths

OK I am probably being overly cautious here, but wanted to double check.

Thus far I have treated all my natural dyes with the same caution as chemical dyes. I have read in a book on nautral dyes that you can simply pour the dye baths in the ground when you are done. I wa ted to ask here if there are exceptions to this, in regards to natural dyes of course.

Thank you all,




Most of the dyestuffs are fine to dispose of but the mordants are a different story.  Most natural dyers no longer use chrome mordant but if you do, you will want to know how to dispose of it (and handle it) safely.  A good dye book will help you.  I have often dumped dye baths in the gravel alley behind my house.  If you are on a well, that's a different story.  Like I said a good book will help.


I have several good books, The Dyer's Garden, Natural Color and a huge book, but the title excapes me. There are so many possible natural dyes out there and I know not all plants are non-toxic, which is why I wanted to check with a broader community, before I make any broad assumptions. :)


In Jenny Dean's Wild Colour she talks about this on page 45. Basically, unless using iron, copper or chrome, most mordants are exhausted, like the dye bath. If you have a strongly alkaline or acidic solution and don't want to store it for later she suggests adding much more water and then disposing. She also says if you have any doubt, contact the state environmental authority on safe disposal. Of course things like rhubarb leaves are poisonus to pets (and people!). But that's another issue.


Thank you Shawn, as I said in the post, I figured I was being overly cautious. It just seems too easy, but I'm apparently just trying to make it too hard. :)


Always good to be cautious! I think depending on the type of indigo vat, it can be a bit toxic or not. By the way, Wild Colour (and her blog) is my favorite natural dye book.


Hmm Dean's Wild Colour has just further confused me. The Dyer's Garden states that the bath used for alum mordants will merely be acidic and can be poured at the base of plants that like acidic soil. Wild Color states for nearly everything, check with your state authority, which I don't really have living in the UK. I'm sure there is some similar agency I can check with here, but being an ex-patriot, I'll have to look around to figure out which agency to contact. I do also have Natural Dyes by Cardon, which will hopefuly clarify the answer to this question.


Perhaps it depends on which alum? She does say it's non-toxic so that should be a hint. I would treat it like the tannins and dilute if it hasn't been exhausted. I guess maybe she's being extra cautious ;-)


Erica, you are working with a natural set of chemicals with natural dyes so you do need to be mindful of how you handle them and their chemistry

If you could give us an idea of what you are dyeing that would be helpful.  It is very hard to be specific because so many dyebaths have different chemical properties.

Your dye bath should always be brought back to neutral.  Using a ph strip to bring the bath down to 7 or back up to 7 is useful.  Knowing how to bring it back into line as neutral is also useful.  Each bath is different.

Metals can be harmful, chrome and tin come to mind.  Iron can linger in your pots and your studio and sadden future baths.  Dedicate one pot and mixing bowl to iron to keep that sad ghost away.  Your bath should be fully exhausted as possible to ensure the modifers have been pulled into your substrate.  Don't use excessive amounts of the metals so they exhaust.  

Extremes in ph up or down can burn you and kill plants or weaken fibers

Indigo pots are usually high in ph due to the chemicals required, no matter which process is used, use vinegar to bring it down to neutral.  And of course the indigo sludge can be nasty so you want to dispose of it either in a dye pit, in your sewer or allow to evaporate and throw away the residue.

You just have to work within your environment and learn the chemistry one piece at a time.  There is no general rule of thumb for all in one.

Give us some details and we can try to give you guidelines for a specific process.  Deb Mc


Thanks Deb!

So far, I have only used alum on wool for a mordant. Thank you for the tips on metals!

I have so far used logwood and madder. I also have brazilwood, persian berries, cochineal,  cutch  and woad.

Thanks for the advice!


One thing you can do to reduce the amount of "bath" to be discarded is to mordant your material in a LARGE batch pre-season. I'm getting ready for some large batches this summer - I collect the white or light material and mordant with alum - in several small batches that fit the kettle - WITHOUT DUMPING the bath until the last one is finished. I put in only enough alum/cream of tarter for the material in the bath and refresh each time the bath is reheated (doing it this way saves energy, too). At the end of a few days, I have several pounds of mordanted fiber drying slowly (makes the mordant work better later) - to be stored until I run a dye bath. Then when I heat up the marigolds, madder, or tansy - the dye bath is rather harmless but for the plant matter. The mordant is not leaching into the dye bath in significant quantities.