Category Archives: dye safety

Are “Greener Shades” dyes really safer than other acid dyes?

Name: Kathe

Country or region: Denmark

Message: Hi Paula, I would like to read your article on Greener shades dyes vs acid dyes, but it not available on your site, can your help, please? I have been looking for MSDS on these dyes online, with no luck. The dyes are not available in Denmark, but I would like to find out if they really are safer than other acid dyes.

Hi Kathe, I was able to find the article you were looking for. Unfortunately I have never been able to resurrect the Dye Forum, but the Internet Archive has, wonderfully, made a record of its old postings. Here is the original query, followed by my lengthy response, and another dyer’s followup message….

Greener Shades vs Acid dyes

Hey all, I am a professional dyer who has been dyeing with Acid dyes for years with wonderful results. All my colorways are based on these Acid dyes. Recently, I have begun to wonder about the impact of what I do on the environment and so have looked at Greener Shades dyes. After reading the instructions, I see they are actually very similar to the Acid dyes (in processing the color). That makes me wonder if they are really substantially better for the environment or if they are just saying that to sell the product. The label says they do not release heavy metals but I was wondering which class of dye does? Do Acid dyes release these heavy metals or are they referring to vat dyes or Lanaset dyes or what? I want to be sure, before I go to all the time and expense of completely changing my line, that I am in fact doing something to help the world and not just falling for an advertising gimmick. Could anyone one who has looked into the facts please tell me what they have discovered? I would greatly appreciate it. Gale

By gale evans at 2011-08-09 06:24

Greener Shades not so impressive

The Greener Shades dyes are chrome-free acid dyes, but, 1, that’s true of many dyes already on the market, and 2, chrome-containing premetalized dyes are not all that bad, at least when used in the small quantities needed for hand dyeing. The fact that the Greener Shades company does not give any Colour Index names or any other generic names for their dyes makes it impossible to know whether to trust their MSDS forms (which incidentally, are very confusing, apparently ranking midnight black as both severely hazardous and perhaps not hazardous at all – very bad MSDS writing!).

Apparently the Greener Shades do not have Colour Index names at all, which makes me suspect that they might be too new to have had thorough safety testing. They list their Organic Processing Compliance Testing Results, but apparently these refer only to heavy metal content, and say nothing else about the safety of these dyes for the environment! There are plenty of dyes which are free of significant metal content but which will kill fish if they get into streams. If a dye persists in the environment and is toxic to animals, plants, or microbes living in it, it would be no better than a dye that contains a little heavy metal.

What bothers me the most about their claims is that, while their MSDS pages give too little information to reassure me, they have no safety testing certification at all. I need to know what the generic names for dyes are, so that I can look them up elsewhere to find out whether they pose any particular hazard. Since Greener Shades does not give this information at all, we can have no idea how safe these dyes really are to use.

Chrome dyes, by the way, are a class of synthetic dyes that are mordanted, as natural dyes can be, with dangerous carcinogenic hexavalent chromium (sold as potassium dichromate). They have both better leveling AND better washfastness than other classes of wool dyes, where normally a wool dye’s leveling is inversely proportionate to its washfastness, and vice versa. However, I do not recommend the use of chrome dyes by artists (not that any of us have a good source for buying them), just as I do not recommend the use of natural dyes that are mordanted with chrome. There’s too much risk of exposure to the hexavalent chromium, and such a large amount of the hexavalent chromium in the mordanting process is used that it’s bad for the environment, as well. Metal complex dyes, or premetalized dyes, which includes many of the Lanaset dyes, are NOT dangerous like the chrome dyes and the natural dyes that are mordanted with chromium. Metal complex dyes have a smaller number of chromium atoms included in their molecular structure, and they are in the vastly safer trivalent form. Only the hexavalent form of chromium is a known human carcinogen. Incidentally, most exposure to hexavalent chrome occurs in applying industrial processes that do not include textile dyeing.

My conclusions for now:

1. Go ahead and use those of the Lanaset dyes or other premetalized dyes that contain chromium, in small quantitities, mixing up no more dye than you are likely to use, and disposing of them as per EPA regulations, which require that the dyes be diluted if they are put down the sewer (household waste water being suitable for this purpose). (As I explained in my All About Hand Dyeing Blog here, “a dye painting solution of 1 teaspoon of Jet Black Lanaset dye that contains 2.5 grams of dye, dissolved in one cup (250 ml), contains 0.08 grams (which is equal to 80 milligrams or 80,000 micrograms) of chromium. After being diluted with 50 gallons of uncontaminated water, this dye concentration would meet the US EPA standard for chromium content of drinking water in the US, which is 100 micrograms per liter.”)

2. If you want to avoid heavy metals, use only those Lanaset dyes which are metal free (see my page, Which Lanaset dye colors are pure, rather than mixtures?), or use other classes of acid dyes which do not contain heavy metals, such as most of the WashFast Acid Dyes (with the exception of the Jet Black, which is a premetalized dye).

3. If you order from Greener Shades, insist that they give you certification of environmental safety testing, not only for lack of heavy metals, as provided by a named third party company, but also for the potential environmental dangers of the specific dye molecules used. Do not ever accept vague claims of safety that are not backed up by a certification and the contact information for the company that did the testing, because it’s so easy for a company to make claims that are not backed up by any proof.

To find out whether the acid dyes you use contain heavy metals, check the MSDS information for them. Your dye supplier should give you this information; both ProChem and Dharma make things easy by supplying them on their website, but others will send you the MSDS with an order, or following an order, for whatever you have purchased from them. You could also post about your favorite dyes here, so we can discuss their safety.

If a dye contains a heavy metal in its chromophore, it’s probably only a problem when it is used in large industrial quantities. There is absolutely no reason, for example, for a hand dyer to worry about the 2% of the weight of turquoise dyes that is present as copper; almost all good bright turquoise dyes contain a copper atom in their chromophore. (This is true of the Greener Shades aqua color, as well!) The copper ion remains bound in the dye molecule until it is broken down, and it is not present in harmful quantities unless you are running a large dyeing factory. The salt used with the dye is probably of larger concern, environmentally.

You mention vat dyes. The environmental and safety aspect of using vat dyes, such as natural indigo, is that you must use significant quantities of lye and other chemicals, unless you are using one of the very slow and less predictable fermentation baths; however, these chemicals are not bad once their pH has been neutralized. Vat dyes do not require mordants.

In most lines of dye, a few colors contain small amounts of heavy metals such as copper. Other colors often do not.


By pburch at Tue, 2011-08-09 07:11

Greener Shades Coral Reef Agua

This color does contain copper and does not meet organic specs. This info is buried on the Greener Shades FAQ page, But this info is hard to find and not front and center on the main page. Further if their non-toxic quality is the reason for selling them as “Greener shades” why is it being sold at all? Many dyers are shocked to get this info after using them.

“Why do you carry a dye, Coral Reef Aqua, that does have a heavy metal in it?”

“To get a really true and bright aqua or turquoise color, it is extremely difficult to do so without the introduction of some sort of metal compound. Our customers demanded a turquoise color, so we had to compromise on this one color. The heavy metal used is copper and the dye analaysis is listed in the “Dye Info” section of our website. This color does not meet the requirements of the Organic Trade Association for organic textile processing, but it is still manufactured with the same high quality performance and sulfonation balance as our other colors.”

By brigidsfarm at Tue, 2011-08-16 09:18

I can’t, as I write this, view the Greener Shades website because for some reason my web browsers are telling me that the site is not safe to connect to, so I can’t see if their current claims have changed at all. However, the Greener Shades Dyes FAQ is printed on the website for the C & M Acres Fiber Mill; it claims that the dyes are safer solely because they do not contain metals, although in fact one of them does, and metals are not always a significant danger for dyers. Furthermore, there are many dyes which are quite dangerous to use, in spite of their being free of heavy metals, such as some of the Naphthol dyes; I’m sure that the Greener Shades dyes are much safer to use than the more dangerous of the Naphthol dyes, but the fact that they are metal-free is irrelevant with respect to the many dangerous organic chemicals that exist. We need Greener Shades to supply more proof of the safety of their dyes, before we can have any reason to believe their claim that their dyes are safer.

There is one group of acid dyes that are probably safer than other acid dyes, which are the food coloring dyes. Unlike (as far as we can tell from the information they supply) the Greener Shades dyes, food coloring dyes have been proven to be quite safe to work with, because they have been tested for being reasonably safe even when eaten (though I confess to feeling that people should not eat them often, and certainly never in the quantities found in a confection called Red Velvet cake). See my page, “Using Food Coloring as a Textile Dye for Protein Fibers“.

You can browse the Internet Archive’s copy of the Dye Forum at their website at

You are also always welcome to ask me to help track down any information I can find.

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Do turquoise acid dyes contain chrome?

Ann McElroy asked on Facebook,
I had thought turquoise acid dye had chrome in it. Someone told me they don’t use chrome anymore. I couldn’t see anything on your site. Do they still use chrome?

Chrome is certainly still used in many dyes. It’s invaluable for making long-lasting dyes for wool, dyes that are resistant to washing and fading. Chrome that is contained in the molecular structure of a dye, as in the metal complex or premetallized acid dyes, is far safer for us to use, and for the environment when we dispose of any excess, than the use of chrome as a mordant. I strongly recommend against using chrome as a mordant, but it is not difficult to safely use chrome-containing acid dyes.

Chrome mordants are far more dangerous than chrome-containing acid dyes for two reasons: they contain the carcinogenic hexavalent form of chromium, instead of the safer trivalent form found in the metal complex dyes, and the quantity of chromium present is vastly greater in the chrome mordant solution than in the metal complex dyes.

Which turquoise acid dye you are talking about is another story. There are so many different types of acid dyes! The only way to answer this question is to look at each of the commonly used turquoise acid dyes separately. (It is a good idea to look at the MSDS from your dye seller for each individual color of each dye that you use.)

acid leveling dyes
The old Kiton acid leveling dyes included a turquoise-colored acid dye called Erioglaucine, whose generic name is Colour Index Acid Blue 9. This dye never contained chromium. ProChem no longer sells the Kiton dyes, but the dyes are still used in such lines of acid dyes as Cushing and Landscape Dyes, though no specific information as to which dye types are included in which colors. Interestingly, Acid Blue 9 is the exact same dye that is known as FD&C Blue #1 or E133, which is popularly used in artificially colored candies, drink mixes, and the blue alcoholic liqueur curaçao. This is the dye you’re using when you dye wool with unsweetened blue Kool-aid.

Alphazurine A, or Acid Blue 7, is a popular blue acid dye which ProChem sells as their Washfast Acid Blue 478, Jacquard Products sells as their Jacquard Acid 624 Turquoise, and Dharma Trading Company sells as their Dharma Acid 407 Caribbean Blue. Like erioglaucine, alphazurine A is an acid leveling dye, which means that it is not particularly washfast, but it is easy to use to produce smooth level solid colors. This dye, too, never contained chromium.

Lanaset dyes
Among the Lanaset line of acid and reactive dyes for wool, ProChem sells Sabraset Turquoise 480, and Maiwa sells the same dye, as Lanaset Turquoise 5G. While some of the dyes in the Lanaset dyes do contain chromium, the turquoise does not. This dye does not have a Colour Index generic name, but we know its full chemical name, which indicates no heavy metal component. The MSDS also indicates no heavy metal content.

copper-based dyes
There are many turquoise dyes that are based on the beautiful copper phthalocyanine ring, which has a large flat molecule structure similar to that the the hemoglobin ring in blood or the chlorophyll ring in green plants. (Each of these rings has a metal ion in the center; where phthalocyanine has a copper atom in the middle, hemoglobin is centered on iron, while chlorophyll is centered on magnesium, and the pink molecule of vitamin B12 is centered on an atom of cobalt.) There is no substitute for copper phthalocyanine if you want a particularly bright clear turquoise; all of the best bright clear turquoise dyes, of whatever class, are based on this structure. None of these phthalocyanine dyes contain chromium, as they use copper, instead.

Among the very bright clear turquoise dyes based on copper phthalocyanine are the fiber reactive dyes, Procion MX turquoise and Remazol turquoise. Although these fiber reactive dyes are usually used on cellulose fibers such as cotton, along with a high-pH substance such as soda ash, if they are used on protein fibers such as silk or wool, in the presence of an acid such as vinegar, and heat-set with steam or in a simmering dyebath, they actually function as acid dyes, thanks to the sulfonate groups which are also what make the dyes soluble in water. An acid dye based on the same copper phthalocyanine ring is Acid Blue 249, but I don’t know of a source for this dye for hand dyers. The brightest turquoise acid dye is Dharma Acid Dye #424 True Turquoise; this dye is classified in the Colour Index as a direct dye, Direct Blue 86, for historical reasons (it was described as a direct dye first), though the only difference between it and Acid Blue 249 is that it has only two sulfonate groups, whereas Acid Blue 249 contains four of them. Like the reactive Procion turquoise, it works well when used on wool or silk in an acid dyeing recipe, along with an acid and moist heat. Below are pictures of the structures of Acid Blue 249 and Direct Blue 86:

The amount of copper in the copper phthalocyanine dyes is only between 1% and 5% of the dye, by weight, not enough that we have to worry about toxicity or environmental damage being caused by it.

metal complex dyes
As a general rule, only those dyes which are classed as premetallized, or metal complex, contain chromium. (The phrase ‘metal complex’ refers to the exact same dye class as the word ‘premetallized’.) These dyes tend to be exceptionally washfast and lightfast, but usually duller in color than the leveling acid dyes. An excellent example is the black dye contained in Lanaset Jet Black (in combination with another dye), as well as ProChem’s Washfast Acid Black 672 and H.Dupont’s Noir Concentre. These metal complex dyes are so wash-resistant that they are washfast even in hot water, at 140°F, rather than only in cool water like other types of acid dyes. The “Cr” in the center of the chemical structure, below, for Acid Black 172 stands for the chromium atom that helps to make this such a permanent dark black dye.

As far as the safety of the hand dyer is concerned, I feel that there is no need to worry much about whether or not a particular dye contains chromium. You should be cautious never to eat or breathe any textile dye, and always wear gloves when working with it (though obviously you can be more relaxed with Acid Blue 9, since it has passed safety testing for use as a food dye). It is always especially important to avoid inhaling dye. The quantity of chromium in good-quality dyes is low enough that ordinary caution is adequate, when working with small quantities. For example, I calculated, in the October 6, 2006 entry in my blog, that one teaspoon of Lanaset Black B dye powder contains 0.08 grams of chromium, which after being diluted with fifty gallons of water, as when discarded down the drain with household waste water, will meet the US EPA standard for chromium content of drinking water in the US, which is 100 micrograms per liter. This is in the trivalent form of chromium, which is far less hazardous than the hexavalent form of chromium.

In contrast, I recommend strongly against using chrome as a mordant in hand dyeing. The chromium in potassium dichromate is in the carcinogenic hexavalent form. One recipe (in Liles’s Art and Craft of Natural Dyeing, 1990) calls for 10 grams of potassium dichromate per pound of wool, in a five gallon dyebath. This is a very large amount of chromium, compared to the amount of chromium in a metal complex dye, and it is in a far more dangerous form. This quantity, if swallowed, is enough to kill several people; lower doses, whether swallowed, inhaled, or absorbed through the skin, can cause severe burns, blindness, birth defects, kidney damage, cancer, and other harm. (See PubChem.) The chromium that becomes a part of the dye-fiber complex is transformed to the trivalent form, but the risks of working with potassium dichromate in the home are too great.

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questions about silk dye safety

Name: Anna
Country or region: France
Message: Hello,
Thank you for your website and all the information that it provides. You are offering the world with a wonderful service. If you wouldn’t mind, I would love to have your opinion on a few inquiries.

My mother has her brand of silk clothing that she has always dyed herself, and ever since childhood my family has been exposed to various types of fumes, including those from dyes (mostly acid dyes from the polish brand Kakadu, if this rings any bells ) but also fumes from steaming screen-printed silk, which always produces an awful smell and always felt to me like this could not be a good thing to be breathing near. So I guess my question is, what could be the risk of exposure to such fumes ? Is there any literature and studies that may enlighten me on the matter? I personally am experiencing a tightness in the chest area since spending a few months with my mother, and it raised my concerns regarding my health as well as my mother’s and her employees.

It’s difficult to talk about the risks of fume exposure without knowing what kinds of dyes and other chemicals have been used. I can’t find any information on the Kakadu brand of textile dyes. It would be helpful if you can request MSDS (Materials Safety Data Sheet) information from the seller for each of these dyes, but even that will tell us nothing about what dyes and other chemicals may have been contained in older, now discontinued, formulations of the same brand of dyes. (See, for instance, the question “Did Sennelier Tinfix Silk Dyes cause my wife’s hyperthyroidism?“, in my old dye Q&A blog, for a case in which it was impossible to find MSDS information for a discontinued dye formula.)

The tightness in your chest might be due to asthma caused by an allergy to the dyes. Asthma is a known occupational hazard for workers in the textile dye industry. This is normally an issue only with powdered dyes, as dyes are less likely to get into the air while they are dissolved in water. Experience with my relatives with Chronic Obstructive Pulmonary Disease (though they did not work with dyes) makes me worry about actual lung damage from exposure to unsafe chemicals, though I don’t know of any particular relationship between COPD and the sort of exposures you report. I would encourage anyone suffering from tightness in the chest to see a doctor. A spirometer can be used to test your lung function.

Once a person has a demonstrated allergy to a particular type of dye, that person should stop using that type of dye at all, and switch to other types of dye. For example, one well-known quilt artist developed an allergy to Procion MX dyes and had to switch to the very similar Cibacron F dyes (now known as Novacron F dyes). Continued exposure to a substance to which one is badly allergic can result in a serious case of asthma.

Do you, yourself, take particular precautions when exposed to fumes, whether it is by adding ventilators, air purifiers, plants to your environment or special diet or supplements to keep you from storing toxic compounds in your soft tissues ?
I remember reading an article a few years back about the use of algae and chlorophyle in general as well as the use of glutathione supplements to protect workers from air born toxins in the denim industry, but I can’t seem to find anything on the subject as I am looking today.

As a rule, I don’t believe in nutritional supplements to counter toxic exposures. There have been many, many cases in which useless substances are promoted for this purpose solely for the enrichment of the those selling them. The supplements I have seen being promoted for this purpose are generally nothing more than useless scams. Neither algae nor chlorophyll is likely to have any beneficial effect. Glutathione, if given in time, is an effective antidote for overdoses of acetaminophen (whose other generic name is paracetamol), and has other medical uses, but again I would not rely on it to counter unspecified toxins. [Correction: N-acetyl cysteine is the antidote to acetaminophen/paracetamol poisoning, used for its ability to increase the body’s levels of glutathione. Glutathione itself is subject to breakdown in the process of digestion.] In general, dietary intake of antioxidants in food, particularly in colorful vegetables and fruits, is helpful (for example, there are scientific studies suggesting that eating curry may be good for lung function in COPD, because of the antioxidants found in turmeric), but, again and again, the isolated nutrients have proven useless when given in the form of dietary supplements.

I do take precautions when dyeing, and it is important for all dyers to do similarly. The first step is to avoid breathing the dust generated by handling dye powders. This is the most common hazard in handling dyes, as even non-toxic dyes, like many other powders, are capable of producing severe allergies and asthma if repeatedly inhaled. A dust mask is usually sufficient, but only if it fits so well that no air comes in around the sides of the mask. All air that is breathed must come directly through the filter material of the mask in order for it to provide protection.

Of course it is unwise to eat any dye that has not been cleared as being safe for human consumption. This means that hands must be protected with waterproof gloves, and washed before eating or smoking. This sounds obvious, but I have many times seen artists eat a sandwich or smoke a cigarette with unwashed hands covered in  oil paints whose pigments were known to be very toxic, such as cadmium red and chrome orange! While most of the dyes we use are  unable to penetrate a waterproof glove without any holes, and in most cases of glove punctures stay in the outer layers of skin rather than penetrating inside the body, sometimes basic dyes (also known as cationic dyes) have been used like acid dyes, or even sold as one or two of the colors in a line of acid dyes. Basic dyes are, in general, more dangerous than acid dyes or fiber reactive dyes, because, unlike these other dye classes, basic dyes have a positive electric charge that encourages them to cling to and penetrate skin.

When handling small quantities of objectionable solvents, such as the alcohol used to dilute some silk paints, a dust mask is of no use at all. Make sure to have good ventilation. A good way to improve ventilation in your work area is to use electric fans in two windows, one on each side of the work area, with one fan pushing air outside through one window, while the other fan sucks air inside through the other window. Cross ventilation is much more effective than a single open window.

Larger quantities of dangerous solvents require more precautions, not instead of, but in addition to, having excellent flow-through ventilation. It is important that the amount of a solvent or other chemical in the air be no greater than the safe vapor concentration for that chemical, which you may be able to find in the MSDS safety information for that substance. Any significant exposure to chlorine bleach, for example, calls for a well-fitting respirator (not merely a dust mask) with an acid gas cartridge. Different toxic substances require different kinds of cartridges. Some solvents, such as alcohol in fabric paints, or the volatile solvents used to dissolve gutta in resists in silk painting or for dry-cleaning, cannot be adequately screened out by a respirator.

I myself purchased an extra stove burner specifically for use out-of-doors when dyeing polyester, because the carrier chemicals used with polyester dyes are unhealthy to breathe (and smell horrible). Boiling these chemicals indoors would have permeated the entire living area; it’s impractical to outfit everyone in the house with a proper respirator, and unpleasant to wear one for more than a few minutes anyway. When working in a lab, I would use a fume hood to work with similarly noxious chemicals.

Also, do you have the knowledge of any association that could provide specific guidelines for the work place environment and safety when it comes to silk dying and screen-printing ? My wish is to really do all that is in my power to protect those around me and offer a pleasant work environment.

PRO Chemical & Dye’s Studio Safety Guidelines are good, though brief.

Although it is not a new book, I very much liked the information on setting up a safe dye studio in Deborah M. Dryden’s book, Fabric Painting and Dyeing for the Theatre. Probably the best book for me to recommend to you would be Monona Rossol’s 2001 book, The Artist’s Complete Health and Safety Guide. Both of these books identify specific hazardous dyes that should be avoided altogether, since there are safer alternatives. Most of the dyes in question are direct dyes, while a few are acid dyes; none are fiber reactive dyes.

Dye sellers who mix different dyes together to make different colors will probably not reveal which specific dyes are in a given dye color, as this is a trade secret, but they should provide information for all of the dyes that they use in their mixtures in any particular line of dyes. Any company that sells dyes should provide MSDS information so that you will know whether to be more concerned about the safety of their dyes.

Dyes based on benzidine, o-toluidine, or o-dianisidine are dangerous, because, after being absorbed by the body, they can be metabolized back to the carcinogenic chemical they were made from. Benzidine is the compound of greatest concern. In order to know for certain whether any of your dyes present this hazard, you have to have the MSDS page for each dye. With some types of dyes, it is not difficult to get this information, so you can feel safe from these chemicals. With dyes whose manufacturers do not identify the dye chemicals or make MSDS information available, there is no way to tell.  Until the early 1980s, these dyes were in common use, without warning labels. The dyes are listed Rossol’s book and in a US Government publication from 1980, “Health Hazard Alert–Benzidine-, o-Tolidine-, and o-Dianisidine- Based Dyes“, which can be found in the Internet Archive.

The main hazard from serious exposures to benzidine, o-toluidine, or o-dianisidine is an increase in the risk of bladder cancer. Once someone has been exposed to these chemicals, the most important single precaution to take is to avoid tobacco smoke, since previous exposure to chemicals that cause bladder cancer increases sensitivity to future exposures, and tobacco smoke is a major cause of bladder cancer.

A paper on the University of Illinois at Chicago website, Silk Screen Printing, written by Ronald Fuchs and Michael McCann about the dangers of silk screen printing, focuses on the hazards of solvents for fabric printing inks, such as toluene, and advocates the use of water-based inks, instead. The screen-printing inks, which are based on pigments rather than dyes, are different from dyes used for printing silk fabrics, as the dyes used on silk are water-based.

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