Author Archives: pburch

About pburch

Paula Burch is a scientist with degrees in biochemistry and biology who became frustrated with the difficulty of finding user-friendly information on the chemistry of dyes and resolved to find and share the information dye artists need to take full advantage of their materials. She established her All About Hand Dyeing website in 1998.

Dye disposal & dyeing in kitchen/eating area

Hi Paula,

I have been looking for information about good safety practices when dying with fiber reactive Procion dyes. You posted a response to another person inquiring about safety that referred to information from Dharma Trading and There appears to be conflicting advise online about this topic so your input would be much appreciated.

Generally the safety advise I see online is “don’t inhale it and don’t ingest it.” I used Procion dyes this weekend on a stove top. The dye splashed out of the pot onto the rest of the stove top. I did place newspaper to minimize the dye getting on my food surfaces. I also used the sink to place tools with dye and to rinse them out. Since I also wash dishes in the sink, I am concerned that I am potentially contaminating my eating area. I use only dedicated tools for dying, but a sink is also a tool. Seeing RIT videos with demonstrators
using the kitchen for dyeing, I thought it was safe practice. advised not to eat or drink were dyes are used. Likey I won’t use the stove to method again. If I dye again, I will only use my pot in the tub and clean there too. Any advise or guidance will be much appreciated. Thank you for all the information you have provided on your site! It is so helpful!


Hi Jennifer,

I haven’t been able to work much lately, but I want to try to answer your questions.

I believe that you should scrub your stove top and sink thoroughly with a mildly abrasive substance such as Bon Ami cleaning powder. Rinse thoroughly. (I’m sure you’ve done this or the equivalent already.) And then, don’t worry about it. I am much more concerned about easily scratched surfaces, which are difficult to get clean, so I would not recommend ever reusing a plastic surface for food, but an impervious surface, such as stainless steel, porcelain, or glass, can be cleaned pretty effectively. Not enough that we would trust it to remove all traces of truly dangerous substances such as hydrofluoric acid, or mercury compounds, but effectively enough for reasonably safe household chemicals such as Procion dyes. Of course you should clean until no trace of color is visible, and then clean more, after that; this should be sufficient to reduce any possible contamination with the dye to very low levels.

Procion dye is safer than All Purpose dye, because we can find out from our suppliers exactly which dyes are used in the Procion dyes we buy, but it is impossible to get any idea at all of what dyes are contained in any All Purpose dye mixtures that are sold, because the manufacturers keep it all a secret. Until the 1980s, Rit All Purpose dye contained known carcinogens, such as benzidine. See these pages I wrote:

Procion dyes do not contain known carcinogens such as benzidine or o-dianisidine. We try to be careful, though, because there’s no telling whether some of them might turn out to be bad when ingested or inhaled. Unless a dye has been safety-tested, it should be treated as though it is dangerous, even if it seems likely that it is not very dangerous. Consider the many different food colorings that have been used in processed foods for years, only to be banned after it’s found that they may slightly increase the risk of cancer in those who have eaten them.

There are other types of dyes that I do not think you should ever use in your kitchen, specifically a kind of dye called basic dyes, or cationic dyes, or another kind of dye called naphthol dye. Like the old versions of All Purpose dyes, they are known to contain carcinogens or mutagens, and therefore present a much higher risk.

To help put things into perspective, a very interesting related problem is tattoo ink. Tattoos or permanent makeup are so popular that it seems rare now to find someone without any, and yet tattoo inks are pretty much entirely unregulated for safety, in spite of any false claims you may see that a given tattoo ink is FDA approved. Tattoo inks are injected deep into the skin; some of the chemicals from the dyes remain in place, while some are removed by the body and circulate throughout before being excreted. A particular concern is the possibility of bladder cancer, since many chemicals of concern are excreted in urine. (The biggest single cause of bladder cancer is cigarette smoking.)

The shocking thing, to me, is that the safest of tattoo pigments are similar to some of the chromophores used in Procion dyes! No tattoo pigments have ever been tested to determine whether they are safe when used in tattoos. After all the effort we go to to keep from excessive exposure to the dyes we use on textiles, many people are having similar pigments, and far worse pigments, injected right into their skin? Other tattoo pigments contain carcinogens and toxins such as PAH (polycyclic aromatic hydrocarbons), which since before recorded history have always been a part of black tattoo inks, and heavy metals such as chromium and cadmium, all of which are far more concerning at even low levels than the fiber reactive dyes we work with.

Dangerous substances are not found only in the chemicals everyone knows to be concerned about. We can also find polycyclic aromatic hydrocarbons in the char produced when food is cooked at high temperatures, as well, including the mess produced when food boils over on the stove and gets scorched by the heating elements. (Grilled food will contain lower levels of carcinogens if the food is marinated first.) Household chemicals such as chlorine bleach, and those that contain it such as dishwasher detergent, are more dangerous than Procion dyes. It’s safe to use bleach on food preparation surfaces only because you rinse it away after using it.

Overall my advice is to try to make efforts to prevent any textile dyes from remaining in food preparation areas, to maintain a clean work area and keep separate pots for dyeing use, but, as long as you are doing all these things, and are avoiding the more dangerous classes of dyes (which you’ve never used anyway), don’t worry too much.

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Can I expect Retayne to fix the dye in a length of handwoven cloth from Myanmar?


I have received a gift of about 7 meters of fabric, apparently hand woven in Myanmar (Burma). It does bleed, a nice turquoise, after testing. It has not yet been washed. I read one of your articles about dyeing jeans, and apparently Retayne does not work on all types of dyes.

Have you had any experience with using Retayne on fabrics from the east? India or Myanmar? Can I expect Retayne to work?


Is the fabric silk or a synthetic? Of course it seems more likely that handwoven cloth is woven from a natural fiber, but you will need to make sure.

If the fabric is silk, then chances are it’s been dyed with an acid dye, or possibly a direct dye. Retayne should work for an acid dye or a direct dye on silk. If the fabric is polyester or acetate, it’s been dyed with a disperse dye, and Retayne will not be able to help.

How can you find out the fiber content of an unlabeled fabric? Snip off a small amount of fabric and try a burn test. Two excellent resources for interpreting the results of a fiber burn test are Griffin Dyeworks’ Burn Test page (see their Burn Test PDF) and Ditzy Prints’ Fiber Burn Chart. To test for acetate or triacetate, try dissolving a bit of thread from your fabric in some acetone-containing nail polish remover.

For more information on Retayne, see my page on Commercial Dye Fixatives.

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Is hydrogen peroxide effective at stopping the damaging effects of chlorine bleach?

Name: Denise
Country or region: United States
Message: Hello Paula –
Hydrogen Peroxide is said to be ineffective as a bleach stop….I have been perusing your website to solve a problem I have with a Pier 1 seat / back cover for a director’s chair. I wanted to remove the color from the fabric, 100% cotton canvas, but chlorine bleach wouldn’t work! Anyway, I was double-checking about a bleach stop to neutralize the bleach I used and I see you still recommend Hydrogen Peroxide. Do you still? I found another resource that says it’s ineffective. It makes reference to a book by Rayna Gillman. Here’s the link: About Bleach Neutralizers, by Natasha Gilani. Let me know what you think ……Thanks. Denise

Thanks for writing, Denise, and thank you in particular for including your reference. I do still recommend the use of hydrogen peroxide for neutralizing chlorine bleach.

Rayna Gillman is mistaken, I think, and I think that Natasha Gilani could use some more authoritative sources. The only mention of peroxide in Gillman’s book reads:

“Anti-Chlor (sodium bisulfite) is the only substance that stops chlorine bleach from destroying fabric. Neither hydrogen peroxide nor vinegar (two old wive’s tales) will do the job. Anti-Chlor is available from ProChem, and a similar product is available from other dyehouses.” (Page 61 of “Create Your Own Hand-Printed Cloth: Stamp, Screen & Stencil with Everyday Objects”, 2008).

There’s no additional supporting evidence, and no reference for her assertion. I think it’s merely an error in which she conflated the effectiveness of hydrogen peroxide with that of vinegar. A larger error is her claim that sodium bisufite is the only substance that can stop damage from chlorine bleach. Dharma Trading Company’s Bleach Stop is a different chemical, sodium thiosulfate; while it is less economical than sodium bisulfite, since a larger quantity of it must be used, nobody (as far as I know) asserts that it is any less effective. I recommend Anti-Chlor over Bleach-Stop only because of the convenience and economy of being able to use a much smaller volume of the chemical; they are equally effective at preventing damage.

In my own experience, hydrogen peroxide, the ordinary 3% strength commonly sold for use as an antiseptic, is highly effective as a bleach stop. Garments on which I’ve used hydrogen peroxide as a bleach stop have survived years of heavy use by my family; when my son eventually wore one of them out, after years of frequent wear (it was a favorite of his), it was the seams that failed, not in the area of the bleached-out designs. This is in spite of the fact that the navy blue dye of that particular shirt was rather resistant to the bleach, so I had left it to bleach for considerably more time than other items. Another shirt even now continues to be worn occasionally by my husband, fourteen years after I neutralized a bleached-out design on it with hydrogen peroxide, and there is still no sign of degradation of the fabric in the bleached-out areas! (Unfortunately I don’t have any unneutralized bleached shirts for comparison.)

Now, hydrogen peroxide might not work if it has been sitting on the shelf for a long time. Hydrogen peroxide is quite reactive and will eventually go bad. If a bottle is still sealed, it may be good for up to three years after purchase, but once the seal has been broken, expect it to last no more than a year. In fact, its full effectiveness starts to decline within a month or two after the bottle has been opened, so it’s best to use a recently opened bottle for critical uses like neutralizing chlorine bleach. I don’t know how fresh my bottle was, but obviously it was fresh enough. I rinsed the bleached fabric with water, and then poured the peroxide over it.

Hydrogen peroxide is less economical than Anti-Chlor or Bleach-Stop, but it’s not unreasonable in cost. It has a real advantage, moreover; unlike either sodium bisulfite or sodium thiosulfate, it doesn’t present any risk to asthmatics. Five or ten percent of people with asthma are sensitive to sodium bisufite and are better off if they avoid exposure to it (though I imagine that using it as a bleach neutralizer would probably be safe even for people with sulfite-sensitive asthma, if they wear a respirator with an acid gas cartridge).

To compare the effectiveness of hydrogen peroxide with vinegar, for neutralizing the hypochlorite in chlorine bleach, it’s worth taking a look at the chemical reactions involved. The chemical reaction between hypochlorite (the active ingredient in chlorine bleach) and hydrogen peroxide is as follows:

OCl- + H2O2 -> Cl- + H2O + O2

It produces chloride ion, which makes sodium chloride, i.e. ordinary table salt, plus bubbles of gaseous oxygen. In contrast, the acetic acid in vinegar reacts with the hypochlorite to produce sodium acetate plus hypochlorous acid:

NaOCl + HOAc <-> NaOAc + HOCl

In the presence of acid, hypochlorous acid degrades to form chlorine gas. It is quite unlikely that a home dyer will use a large enough quantity of acid to produce lethal accumulations of chlorine gas, but the fact (as I’ve heard it) is that hypochlorous acid is even more damaging to fabric than hypochlorite, so it’s hardly an improvement. Deaths and serious injuries caused by mixing chlorine bleach with acids have all involved a much stronger acid than vinegar (a strong phosphoric acid solution used for cleaning toilets has sometimes been mixed disastrously with chlorine bleach). Chlorine bleach as supplied for home use is supplied as a mixture with extra sodium hydroxide in order to help prevent the reaction of chlorine bleach that occurs with acid.

For more information on neutralizing chlorine bleach, please see my page, “How can I neutralize the damaging effects of chlorine bleach?”.

For your canvas director’s chair seat and back, after you have washed out the chlorine bleach and used either peroxide or Anti-chlor to prevent damage from the bleach….although bleach did not work to remove the color, it is possible, though far from guaranteed, that a reducing type of color remover might work. Bleach and color removers work in a different way, so sometimes one works when the other does not. Howveer, some dyes simply cannot be removed, and it is impossible to know what dyes were used in your covers. See my page, “What chemicals can be used to remove dye?”. Alternatively, you might use the old seat and back as patterns to sew new covers from undyed cotton canvas. If a beige color will do, Pier One currently has new director’s chair covers, in “sand”, on sale on their website.

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