How to keep yourself safe when using Natural Dyes
Pottering along the hedgerow , picking berries , leaves and flowers , coming home creating a dye pot and producing colour is both exciting and magical. But do you know what you are picking and handling? The title “natural” in natural dyes can be misleading as it can feel as anything you pick is completely safe but this is not necessarily true. I was happily about to strip elder (Sambucus niger) leaves for a dye bath when I read that they contain potassium cyanide. Hmm! Time for the gloves! I later found that the leaves, twigs, branches, seeds, and roots of Sambucus plants can contain a cyanide-inducing glycoside (a glycoside which gives rise to cyanide as the metabolism processes it). Ingesting a sufficient quantity of cyanide-inducing glycosides can cause a toxic buildup of cyanide in the body.
Taking care when dyeing with botanical dyes is mostly common sense and can be summed up with using simple protective clothing , washing hands after picking dye material and not using anything for dyeing later wanted for cooking.
Health and Safety when Using Natural Dyes
Protect yourself with gloves, face masks and aprons as appropriate
Never use anything for dyeing that you will later want for cooking
Do not eat and drink when using dyes or mordants.
Dispose of used dye baths responsibly. That is dispose of down the foul drain with plenty of water, or into a soak away away from food plants
Keep dyes and mordants away from children and pets
As far as you can, inform yourself so you know what you are picking and handling especially if picking a variety of plant material to experiment with. Most if not all dye books explain the hazards of any of natural dye materials used. The book, for example, about potassium cyanide in elder came from Judy Hardman’s book1. Common plants used for dyeing that may be a problem are Rhubarb leaves which contain oxalic acid which is both a mordant and poisonous. Bracken sometimes used by dyers for yellow has spores that are thought to be carcinogenic but Ragwort Jacobaea vulgaris, another common plant sometimes used by dyers, is only considered theoretically poisonous to humans as it is not used as a food source being very bitter. However it produces a yellow of which there are plenty of sources so why use it when it could -just-be risky. Especially as it can cause an allergic reaction. (Please note however that this is not an complete list of hedgerow or garden dye plants that could be a source of harm)
Swapping a moment from hedgerow dyeing to using the great dyes of the world such as indigo, madder and cochineal can be misleading too. Not necessarily so much in the dyes but in the mordants, the chemicals used to fix the dye to the fabric. Modern dye books , mostly environmentally conscious use the safer mordants. These are in order Alum ( Potassium Aluminium sulphate) Iron (Ferrous Sulphate) and possible Copper ( Copper Sulphate) although this is poisonous. Some, fortunately few, use Potassium Dichromate (Chrome) .This is a chemical I would not use, and do not recommend even when safety precautions are carefully followed.
The safest mordant to use is Alum followed by iron, which I use in the form of rusty nails, added to a dye bath to gently change a colour from yellows to soft greens, from reds and purples of cochineal to purply greys. I also modify the colour with ammonia which brightens yellows, changes the purple of logwood to dark blue for example and in the case of one of the dyes I adore, Tickweed (Coreopis tinctoria) ammonia changes the yellow to burnt orange. Follow the instructions on the bottle of household ammonia, use sparingly and in a well ventilated space.
I hope that reading this blog does not put anyone off from using natural dyes but instead enables people to keep happily dyeing safely.
Judy Hardman: Natural Dyes
Publisher: The Crowood Press