Rit Dye Liquid
Rit Liquid Dye is an all-purpose dye that works on cotton, nylon, and wool, but not polyester or acrylic. Use a cationic dye fixative to stop the dye from running in the laundry
Procion MX Dye
When mixed with soda ash, Procion dyes are permanent, colorfast, and very washable. You can easily create a palette of brilliant colors ranging from light pastels to deep, vibrant hues. Stays bright much longer than all-purpose dye
Sometimes I see someone claim that
all-purpose dye, such as Rit® brand all-purpose dye, is safer than fiber reactive
dye, such as Procion MX type dye, apparently for no better
reason than that Rit has been sold in US grocery stores for
decades. However, there is no basis for this claim.
All purpose dyes such as Rit® used to be more toxic than they
are now, but that does not mean that they are now safer than
fiber reactive dyes.
All-purpose dyes are a mixture of direct dyes for cellulose fibers and acid leveling dyes for protein fibers. Up until the 1980s, the all-purpose dyes that are so readily found in grocery stores almost everywhere used to contain some direct dyes that were based on benzidine or o-dianisidine, which are known
carcinogens. See the US government document, Health Hazard Alert--Benzidine-, o-Tolidine-, and o-Dianisidine- Based Dyes [PDF].
All-purpose dyes such as Rit® used to contain a carcinogenic direct black dye, for example, according to Deborah M. Dryden's book,
Fabric Painting and Dyeing for the
Theatre; as she wrote, we do not know for certain what all-purpose dyes now
contain, because the manufacturers do not list
the chemical contents on their packages. Some dyes are still sold in the US that contain direct dyes based on o-dianisidine, but the MSDS information for Rit® dyes does not mention them, so we can hope that this is no longer a problem with them.
Unlike direct dyes, there are no fiber reactive dyes based on benzidine or o-dianisidine. As a result, we know that fiber reactive dyes such as Procion MX are much safer than many
types of dyes, but, like all dye powders, they should still not be eaten or
breathed. They should not be given to children to use until
the children are beyond the stage of foolishly putting such
things in their mouths, and adults should always supervise
children closely while they are using dyes (as is necessary
to prevent accidental damage to the decor, as well).
There is one type of dye that is safer than any other type of
dyes: FD & C certified food colorings. These dyes have been tested for
safety when used in foods, which is far more stringent than
the testing for any art material. Art materials marked
"non-toxic" are not considered safe to eat, as a rule. It is
possible to use food colorings as dyes for some fabrics and yarns. They will wash out
of cotton and other plant fibers, but will be okay if the
item made is never washed, as in the case of some ephemeral
children's art projects, and they are good dyes for animal
fibers, such as wool, when used with an appropriate acid, such
as vinegar, and the right amount of heat.
There are many dyes which are much less safe than fiber
reactive dyes, including basic dye for acrylic and naphthol dyes for cotton. Greater care must
be taken in their use. I recommend against home use of napthol dyes and some basic dyes.
Some acid dyes are possible or probable carcinogens. It is best to patronize dye suppliers that will specify which dyes they use by the generic Colour Index names; though you cannot expect them to tell you which dyes they use in any particular color blend, they should be willing to give you the entire list of dyes that they may use in their mixtures. For example, see the lists of dyes in my FAQ, such as Which Wash Fast Acid dyes are pure, rather than mixtures?, and Which Procion MX dyes are pure, and which are mixtures?. Once you have a generic Colour Index name, you can search for more information about the safety of a particular dye, so that you do not have to blindly trust in one company's claims in an MSDS.
Always be careful to avoid breathing any powder, including all dye powders, and avoid eating anything which may have been contaminated with even minute amounts of any dye other than safe food coloring.
Page created: August 11, 2002
Last updated: May 30, 2008
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