Category Archives: acid dyes

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.

-Paula

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, http://greenershades.stillrivermill.com/faq.php. 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

http://web.archive.org/web/20080501203518/http://www.pburch.net/drupal/?

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

(Please help support this web site. Thank you.)

Paula

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.

safety
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.

(Please help support this web site. Thank you.)

-Paula

Are Dharma Acid Dyes grouped as warm versus cold colours? Which are the best to start with?

Name: Rebekka
Country_or_region: UK
Message: Thank you for your website. I have a question concerning Dharma Acid Dyes. They have several primary colours. Do you know if they group them in warm and cold colours as Jacquard does? Which ones are the best to start with?

Best wishes,
Rebekka

Warm colors are those with red in them, while cool colors are those with blue in them. A very pure cyan, magenta, or yellow can be used equally well to mix either warm or cool colors. This is why printers can produce any hue by combining just cyan, magenta, and clear yellow, plus black for darker shades.

If a dye’s color is not a pure enough cyan or magenta or clear yellow, however, it cannot be used to produce all hues. If a blue is more indigo than cyan, it will work well for mixing purples, but poorly for mixing greens. A greenish cyan will be good for mixing greens, but if used to mix indigo blue or purple, it will produce a duller, darker color. A red that is on the yellow side of magenta is great for mixing orange, but the purples it produces in mixtures will be brownish, while a blueish red is wonderful for mixing purples but poor for mixing oranges. A yellow that has too much orange in it cannot be used to mix a pure aqua green, but it works well for more olive-toned greens. This means that, if there is no dye in a particular line of dyes that is a pure printer’s primary, one must obtain both cool and warm versions of each of the three primaries, in order to be able to mix every color.

In addition, dyes have other characteristics that vary, such as how quickly they spread on the fiber before bonding to it. This is inconsequential when one is dyeing solid colors, but can be crucial when the dye is applied directly to the fiber. If it is important that a dye mixture stay together as a single color when painted directly on the fiber it’s being used to dye, then other mixing primaries may be selected whose properties are more similar to one another.

I would recommend that you start with Dharma’s 401 Brilliant Yellow (for both warm and cool), 402 Fire Engine Red (warm), 411 Deep Magenta (cool), either 404 Sapphire Blue or 409 Dark Navy (warm), and 407 Caribbean Blue (cool). You may also want 413 True Black. Other people might recommend a slightly different list, for starting out.

Dharma lists the following dyes as their primary (mixing) colors among their Dharma Acid Dyes:

Warm Primaries:
yellow:
414 Sunflower
Yellow
M acid yellow 135 [also sold elsewhere as ProChem yellow]
401 Brilliant
Yellow
M acid yellow 19 [also sold elsewhere as Jacquard 602 bright yellow and as ProChem WFA Sun Yellow 119]
red:
402 Fire Engine Red L acid red 266 [also sold elsewhere as Jacquard 617 cherry red and ProChem WFA Red 366]

blue:
404 Sapphire Blue L acid blue 25 [also sold elsewhere as ProChem WFA National Blue 425c]
409 Dark Navy M acid blue 113 [also sold elsewhere as ProChem WFA Navy 413]
415 Midnight Blue L acid blue 92
Cool Primaries:
yellow:
401 Brilliant
Yellow
M acid yellow 19 [also sold elsewhere as ProChem WFA Sun Yellow 119]
445 Fluorescent
Lemon
L acid yellow 250
red:
411 Deep Magenta M acid red 131 [also sold elsewhere as ProChem WFA Polar Red 390]
406 Fluorescent
Fuchsia
L acid red 52 [also sold elsewhere as Jacquard hot fuchsia 620 and ProChem WFA Rhodamine Red 370]

blue:
407 Caribbean
Blue
L acid blue 7 [also sold elsewhere as Jacquard 624 Turquoise and ProChem WFA Turquoise 478]
416 Peacock Blue L acid blue 40 [also sold elsewhere as ProChem WFA 440 Bright Blue]

Dharma also lists their 413 True Black as a mixing primary; obviously, black is not a true primary color, but many people use it for mixing darker, duller shades of other colors.

Note that 401 Brilliant Yellow is listed under both warm and cool mixing primaries. This means that it is a very clear, pure yellow, which can be used whether you wish to mix it with reds (for warm colors) or blues (for cool colors). This makes it a particularly good choice to start with.

It’s really a judgment call in some cases, a matter of taste, which you prefer. It’s interesting to compare what different dye suppliers recommend. While Dharma lists their 407 Caribbean Blue as a cool blue primary, Jacquard lists this same dye (acid blue 7) as their warm blue primary 624 turquoise. You can use it as either a warm or a cool mixing primary. Dharma’s 406 fluorescent fuchsia is listed as a cool red mixing primary, but, while Jacquard does sell this dye (acid red 52), they don’t list it as a mixing primary at all, but instead recommend recommend their 618 fire red (a mixture of acid dyes) as their cool red mixing primary; they don’t carry the same dye as Dharma’s 411 Deep Magenta.

Another way to get an idea of which dyes in a particular dye line are considered by many people as the best colors to start with, for mixing, is to look at which dyes are included in their starter kits. PRO Chemical & Dye’s Washfast Acid dye line has some overlap with some of the Dharma Acid Dyes. In their Warm Palette acid dye sampler, they use acid yellow 199, acid red 151, and acid blue 25. This last dye, acid blue 25, is sold by ProChem as National Blue, and by Dharma as sapphire blue. In their Cool Palette acid dye sampler, ProChem includes acid yellow 19, which is the same dye Dharma sells as 401 Brilliant Yellow, acid red 138, and acid blue 90.

Whether to choose fluorescent dyes is another question. Fluorescent dyes are brighter than any others, because they gather ultraviolet light that is invisible to our eyes, and release it as visible light, resulting ina brighter-than-bright effect. Whenever there is a source of ultraviolet light, such as sunlight, or a blacklight, or some fluorescent lights, a fluorescent dye, such as Dharma’s 445 Fluorescent Lemon or 406 Fluorescent Fuchsia, will appear to be exceptionally bright. It will seem less so under a low-ultraviolet light (such as firelight or incandescent lightbulbs). Fluorescent dyes tend to fade faster as the result of light exposure than other dyes, because of the added energy of the ultraviolet light that they absorb, so they are not the best choice for art that is expected to maintain its color unchanged for many years. For archival purposes, it is better to chose more lightfast colors such as Dharma’s 401 Brilliant Yellow instead of 445 Fluorescent yellow, and 411 Deep Magenta instead of 406 Fluorescent Fuchsia, but when the goal is to wow people with exceptionally sharp, bright colors, if longevity is not an issue, the two fluorescent dyes are preferable.

Acid dyes tend to be better at either leveling to make a very smooth solid shade, or at washfastness, but not both (ignoring the existence of reactive dyes such as those in the Lanaset dye line). A highly washfast color is harder to get perfectly level in color, but it does not fade as quickly in the wash. A highly level color is less washfast, though of course this varies according to dyeing technique; typically it is best to dry-clean clothing that has been dye with acid leveling dyes, rather than washing it. Dharma marks their acid leveling dyes, in the dye chart on their Instructions tab, with an “L” for “Leveling”, and their acid milling dyes with an “M”. You can mix the acid leveling dyes and acid milling dyes that Dharma sells, but if you are very concerned with leveling or with washfastness, you will want to look into this further. You can get more information about acid dyes on my website; see “About Acid Dyes”, “Leveling Acid Dyes”, and my page about Washfast Acid dyes.

There is a great deal of important information in the “Instructions” tab on Dharma’s Acid Dyes page. I strongly advise everyone to study this information closely before using the acid dyes.

(Please help support this web site. Thank you.)

-Paula