We get mordant questions all the time at Botanical Colors so why not create Mordant Monday??? Got mordanting questions? Email [email protected]
YOU ASKED: I have some alumimum acetate mordant that is 18 months old. It is kept in a plastic container inside a freezer plastic bag. I heard it has a short life. How do I know when it is not worth using?
KATHY ANSWERED: I have also heard that aluminum acetate has a short shelf life but I asked our supplier and they were unaware of this issue and have never provided us with a “best by” usage date. I’ve used aluminum acetate that was over 5 years old with no difference that I could see. If you are storing the product away from heat, moisture and light, you should be able to use it.
YOU ASKED: I’ve been dying a lot in the last few months. Always with an alum mordant. I just used some copper mordant and find the seafoam color it left on the white yarn really pretty. Can it be used as a color onto itself? Will it remain like that?
KATHY ANSWERED: I would advise you find other materials to achieve the color you are seeking! Copper in the form of copper sulfate or copper acetate is not recommended due to its toxicity. It is dangerous to both humans and aquatic life. Copper is harmful if ingested, damaging to skin and eyes and poisonous to fish. You cannot dispose of the mordant in municipal drains, septic or in waterways and need to take it to a hazardous waste service for disposal.
It’s unfortunate that the company that sold you the mordant didn’t inform you that copper needs to be handled very carefully including PPE so you don’t breathe the dust or fumes and protect your skin and eyes and that they didn’t provide you with a safety data sheet.
This is why we are very specific about mordanting with bio-based materials like symplocos, tannins or alum. These ingredients by themselves are not considered toxic but like all chemicals, they need to be handled with care, following safety instructions. And we always use safety equipment and PPE as we work with these ingredients frequently. Do note that iron (ferrous sulfate) is not safe for children and pets. It is the same ingredient that is found in iron pills and carries the same warnings to keep away from children.
I hope this isn’t upsetting you but I’m concerned that you weren’t advised about your choice of mordants. If you are looking for a seafoam green, you can create a fairly good shade on your wool yarn with Liquid Indigo (Saxon Blue) and Liquid Cutch or Liquid Pomegranate on an alum-mordanted wool yarn.