Name: Gerrie

Message: I have been hand dyeing cotton, both vat, direct and lwi, processing with Procion MX dyes and soda ash for over 15 years.  For the last 8 years I have also been dying silk by soaking in vinegar, using Procion MX dyes then processing in plastic containers and baggies in a dedicated microwave. I always use a dust mask when I mix the powdered dye, and rubber gloves.  I use both types of fabric in my art quilts. 

Recently I twist wrapped a previously dyed and washed silk scarf  (Jacquard Acid Dye test) on an eight inch high Schedule 40 ABS pipe, brushed on Dharma Discharge Paste, rinsed in clear water, soaked in vinegar, applied concentrated Procion MX dyes mixed in chemical water (urea added), placed the pole upright in a recycled cottage cheese container, added more chemical water to cover the fabric and processed in the microwave, 30 seconds on and off for 4 minutes.  I let it cool, unwrapped, rinsed and then washed in synthrapol.

During the process I did not detect any strange odors, I was working at the rear of my garage with the sliding door opened, but when I was done I realized that my lungs hurt.  The pipe surface under the fabric was roughed up a little, but none came off on the scarf.

I have alternatives to use such as Rit Dye Remover, thiourea dioxide, an 8“ empty glass prayer candle container, and clear water, but I would really like to know what caused the lung problem before I try anything else.

I have been scouring your site for safety issues and could only find reference to cooking pvc pipe and the Brito article on discharging in Threads to give me any clues.  What did I do wrong?

Ps: The scarf came out beautifully.


This looks like a puzzle, Gerrie. It may take a little while to figure it out.

The main possibilities are:

1. An allergy to Procion MX dyes (less likely since you use a dustmask, but certainly not impossible)

2. Irritation caused by the sulfur dioxide from Dharma Discharge Paste, which is actually Jacquard Discharge Paste, containing (I'm told) Rongalit ST, as well as ammonia, urea, and water

3. some sort of fumes from heating the chemical water or the plastic - this seems less likely. The only problem with chemical water is if the urea has turned to ammonia, which can be irritating, but you would have noticed the ammonia smell.

4. one of the Jacquard Acid dyes you were using

All reducing discharges, including Jacquard Discharge Paste, produce irritating sulfur dioxide when heated, so that's my first guess. (See the reducing agents section of the page, "What chemicals can be used to remove dye?".) There is no way around the fact that sulfur dioxide is irritating. I know that some people use their discharging microwaves outside, or somehow vent them to the outside, so that they do not get exposed to the fumes. You might have enough fume exposure to have a problem with discharging agents even with your garage door open. You might need to install large fans that pull the air away from your work area. However, you say that you rinsed the discharge paste before adding more dyes and microwaving. Do you heat the discharge paste at all? Do you see the discharging action on the dye before you rinse it? Do you think there may have been any traces of discharge paste by the time you did the last dyeing?

Sulfur dioxide is irritating to everyone, but to someone with a sensitivity to sulfites, reductive discharges may cause more problems. Have you ever had any sign of asthma? Do you have any troubles with sulfited foods or wines? Reductive discharges such as discharge paste, thiox, and Rit Color Remover all produce sulfur dioxide as their active principal. They are all less toxic than chlorine bleach, but there's a special issue with sensitivity (not an allergy) to the sulfur compounds that needs to be considered. (This is completely unrelated to and different from allergies to sulfa antibiotics such as Bactrim, though people commonly confuse "sulfur" with "sulfa".)

PRO Chemical & Dye recommends a NORTH 7700 series Dual Cartridge Air Purifying Respirator for use with thiox or formusol. That's something to consider. This is the same that you would use with hypochlorite (chlorine bleach), which requires an acid gas cartridge. Do you have one of these on hand? If not I would advise you to order one. Dharma Trading Company has another respirator. Make sure you get the acid gas cartridges.

The Jacquard Acid Dyes vary considerably in chemical structure, and belong to more than one sub-class of acid dyes. A reaction  to one acid dye does not necessarily imply that there will be a problem with any different acid dye. The timing of your reaction makes the Jacquard Acid dyes seem a less likely culprit in your case, however.

I hope that you are not developing an allergy to Procion MX dyes. It does sometimes happen. It is more likely to happen to those people who don't wear dustmasks or take other precautions, but it is still possible for an allergy to develop in some susceptible people with only slight exposures, and it is more likely in people who work with dyes all day every day. Caryl Bryer Fallert (see http://www.bryerpatch.com/) wrote on her web site that she had to quit using Procion MX dyes because she developed an allergy to them. She was able to continue with almost no changes in her art by switching to Cibacron F dyes, sold by PRO Chemical & Dye. You'll want to read her FAQ where she mentions this. Acid dyes vary a great deal in chemical structure, so an allergy to one type of acid dye does not necessarily mean a problem with another one, but all Procion MX dyes may cross-react if you are allergic to the reactive section of the dye molecule.

The plastic pipe itself seems to me to be the least likely item to be a problem. I don't think this should produce fumes. I could be wrong, though. ABS pipes are said to produce dangerous fumes when heated with a heat gun (e.g. here). I think that the ABS pipe is most likely just fine to heat the way you did, *IF* afterwards it is not visibly damaged, in shininess, texture, or color, by the heating. However, the change in texture on the pipe that you observed is a bit worrisome.

I think you should be very cautious in your next exposure to Procion MX dyes to see whether or not you seem to have any sensitivity to them. If not, then my guess is that the problem was most likely the sulfur dioxide, which is produced by all reducing discharges, including the alternative discharge materials you have on hand.

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