From the Natural Dyes Yahoo List:
Natural dyed garments have many properties that are beneficial to our
health and are absent in synthetic dyed versions. Prominent among these
are the ability to absorb UV-radiation, bind to diesel fumes (suspected to clog arteries) and change
colour by the action of free-radicals in detergent solutions.The tannic acid mordant and the natural dye have multiple double bonds
that enable it to absorb light in the UV-region. This effect can be
seen by draping a natural dyed fabric on a UV-A lamped used to acquire
a tan and placing a flourescent item (synthetic ruby) on the top. The
synthetic ruby will not glow. The artificial ruby will glow when this
test is done with undyed fabric. In Mumbai, India
I have distributed natural dyed shirts to outdoor workers. They wear
the shirt till it frays as it protects them from the scorching effects
of the tropical sun.On the crowded roads of Mumbai,
fumes of passing busses and lorries (trucks) blow directly onto
passengers travelling by taxis, cars and autorickshaws. A natural dyed
shirt will trap the particles and turn the collars/cuffs black. Natural
dyed apparel inform you of the amount of diesel fumes you have been
exposed to, thereby enabling you to take preventive measures such as:
not overtaking diesel vehicles; keeping your window closed; breathing
through a natural dyed face mask; etc. Hence, although the shirt
darkens, it ultimately helps you make decisions that are better for
your health.Fabric coloured jet black with iron-vinegar and tannic acid will stay
black when washed in detergents that are free of peroxide (bleach)
radicals. In the presence of detergents containing perborates and
percarbonates (the coloured particles in compact detergent powders sold
in India)
the ferrous gets oxidised to ferric giving the black a brownish tone.
We go through a lot of expense to mop up free radicals in our body by
consuming expensive foods rich in vitamins C and E, beta-carotenes,
etc. However we are never warned of common household items like bleach
containing detergents that expose us to these detrimental compounds.To summarise the use of natural dyed fabric helps us make healthier decisions about the lifestyle we want to lead.
Bosco Henriques
Natural Dye Resources
Sawantwadi, India
Ever skeptical, I googled this guy. Found this notice of an award. So maybe there’s something to this notion of naturally dyed fabrics being a litmus strip for chemical danger. Next I want to know what sort of bleaching chemicals are non-peroxide alternatives. Is borax?
I don’t use bleach at all myself. Most stains will come out if you wash them in warm water and hang the item in the sun to dry.
I’m skeptical that natural dyed fabrics are somehow clever enough to show diesel exposure specifically at the collar and cuffs. Mr. Occam and I would like to suggest that collars and cuffs get discolored primarily due to body soil being rubbed into the fabric in those high-friction areas, even if diesel exposure is also a factor (perhaps it shows better or particles are deposited/retained more in the presence of body soil?).
Similarly: oxidizing bleaching agents turn black-dyed clothes to brownish? no surprise. We should limit our exposure to strong chemicals such as oxidizers? again no surprise. Only surprising thing is to those people who don’t realize that oxidization outside the body (chemical damage & hastned decay of materials) is any way related to oxidization inside the body (cell damage). How hard is it to figure that anything that’ll kill mildew can’t be good for your body either?