Body: Name: Drew
Message: I understand that reactive dyes contain heavey metals such as copper in blues and cadmium in reds. Once heavy metals are absorbed into the body they stay there. Is it not dangerious to use a product that contains heavy metals?

I'm afraid that you are drastically oversimplifying the situation. In addition, many, probably most, reactive dyes do not contain heavy metals, and none of the ones that I use contain cadmium.

A great deal depends on what you mean by 'use'. Any use of heavy metals which does not result in their being taken into the body, at any point, is safe. Eating dyes that contain toxic metals would obviously be dangerous, or even bathing in them, but who would do such a foolish thing? It is essential to obtain safety information for each chemical one uses, whether it is a dye or not, and follow appropriate safety rules for their use.

Fiber reactive dye forms a permanent covalent bond with the fiber, so it is certainly not absorbed into the body of the wearer. As a result, it is among the least irritating of all dyes to wear. The fiber reactive dyes are noted for their usefulness as a stain to distinguish living from dead cells (source: Reactive Dyes in Biology, edited by Victor B. Ivanov, ISBN 3-7186-0235-0), because they are absorbed by dead cells, but not by living cells, whose membranes are intact. Nevertheless, it is considered very important to avoid potential toxicity by taking all precautions needed to prevent breathing or consuming the dyes when applying them.

Another important point is that not all metals stay in the body, once absorbed, and not all metals are absorbed, even when consumed - not that we should EVER consume textile dyes! In cases when metals are absorbed, an important question is, how great a quantity is involved? The World Health Organization says that we must actually *eat* between one and three milligrams of copper every day to avoid a nutritional deficiency. Not all forms of copper can be absorbed from the gut; supplements containing copper oxide, for example, are said to be nearly nutritionally worthless, due to the failure of the body to absorb them. In each case, you must consider whether the heavy metal is actually absorbed by the body from a given type of exposure.

Cadmium does not appear to be an issue for the fiber reactive dyes that are commonly used in North America, at least. Cadmium is not found at all in the commonly used dichlorotriazine (Procion MX type) red dyes; their chemical structures are given on this site. A rare and hard-to-find red dye, rubine MX-B, does contain copper; however, red MX-5B and red MX-8B, the two red dyes that are commonly used for mixing and dyeing, contain no metal ions at all in their structure. Mixing blue (blue MX-R) contains no metals, but turquoise (turquoise MX-G) does contain a copper atom. The MSDS (Materials Safety Data Sheet) should list all metals that are found within each dye; your dye supplier should be able to give you one of these for each dye you buy. (If not, you should find another dye supplier.) The heavy metals most likely to be found in dyes, though not necessarily in reactive dyes, are chromium, nickel, cobalt, or copper, in quantities ranging from 2% to 5% of the dye.

Cadmium is much more of an issue for painters, because it is found in many pigments used in oil paints and artists' acrylics, and artists are notorious for eating and smoking while using even the most obviously toxic of paints, and not washing their hands after using them. One of my favorite websites is "Pigments through the ages", which explains the chemical composition of the pigments used in many artists' paints, often involving vastly greater amounts of heavy metals than any dyes do. However, I am personally more concerned with the effects of misuse of solvents; an art professor at my university was said to be near death as the result of a disease caused by exposure to solvents, when I was there, and housepainters have long been reputed to have brain damage due to exposure to the solvents used for their paints. Recent improvements in regulations of the contents of house paints are very welcome, in my opinion. From my own personal observations, there is more of a culture of caution among hand-dyers, who in many cases seem much more aware of proper technique in working with non-food chemicals.

Natural dyes are sometimes used with chromium to make them permanent and also brighter in color, and certain types of acid dyes, which are used in dyeing protein fibers, such as wool and silk, and nylon, are 'premetalized' with chromium. I believe that the question of chromium toxicity is much more relevant to the dyer than any question of potential copper overdose or cadmium toxicity. However, natural dyers all seem to agree that their use of chromium is quite safe if appropriate safety precautions are taken. This is an important issue to investigate yourself before taking up the use of chromium in dyeing.

Heavy metal toxicity is not the health problem that is of greatest concern with respect to dyes. If you scan the medical literature, other classes of dyes have more frequent reports of problems than reactive dyes. Most people who present with dye-related sensitivities have problems with either the Disperse dyes used on polyester and acetate, or the Basic dyes that are commonly used in acrylics. There are a few known or suspected carcinogens among both the Acid dyes and the Basic dyes. The hazard most commonly associated with industrial use of reactive dyes is the development of allergies and resulting occupational asthma. It is important to avoid breathing the dust from dye powders to avoid the development of this problem, though it must be noted that there is quite a difference between occasional hobby exposure and daily industrial exposure to large quantities.

In summary, reactive dyes do not necessarily contain heavy metals; the metals that are found in reactive dyes, when used correctly, are not likely to be absorbed into the body where they can do harm; and there are other hazards to be considered in dye safety.