# Any textile chemists know about odors in denim (long shot)???



## sheepfescue (Jul 29, 2019)

Hello,

TL;DR: Does anyone happen to know of any ACTUAL methods of getting the sulfur smell out of grey jeans and the sulfur-acetic-aldehyde-peppery odor of out blue jeans? Dry-cleaning? Something else?

TL;DR-2: Vinegar does have a legitimate purpose (at least theoretically) in at-home denim treatment, but it has nothing to do with odor removal. And baking soda deodorizing anything is generally an old-wives tail.

This is a super long-shot, but just though I'd put it out there. Recently, I've noticed that blue-jean denim has a sulfur-to-chemical odor that is STRONG and does not come out (despite internet recommendations to do various "baking soda" and/or "vinegar" treatments... more on that below). And then black jeans or dark grey jeans smell of bona-fide sulfur, almost like burnt tire rubber.

I read about the processes of dyeing denim, both blue and black... for the former, it seems various sulfur-containing chemicals (it was tough to get specifics) are used in reductive processes (the indigo blue dye needs to be reduced to become soluble; it is later re-oxidized to be "cured" into the denim)... and then for black denim it seems as though sulfur itself is a component of the black dye and/or a modified "black indigo" dye (which is sulfonylated) is used instead of indigo blue.

(some of the recommendations about vinegar--specifically--actually have other (and more scientifically-sound) roles, such as acidifying one of the indigo blue intermediates to keep more of it in the insoluble state (and thus prevent bleeding dyes).

Here are some things I've thought about that puzzle me:

1. Not all denim (blue or black) even within a brand and lineup of jeans smell (to be clear, some color offerings within a brand across lineups do smell consistently).

2. I did try (on an especially-strongly-scented pair of jeans with hideous sulfur-chemical odors) everything... I tried baking soda and vinegar... I tried putting the jeans outside in a rainstorm (since rain contains trace amounts of ozone which is an oxidizing agent), I tried using 2x laundry detergent, I tried laundry detergents which contain hydrogen peroxide.

3. Not an expert on this, but for something to have the kind of odor that many denims have, the odor-causing substance has to be at least somewhat volatile, or it couldn't be smelled by the wearer of jeans with their nose 24 inches from the denim.

4. I have not necessarily found the smell issue to get better with more expensive jeans. Can't say I've ever purchased a pair above $80 (so maybe it is better with elite jeans), but the only thing that I've found is actually worse with cheap jeans is the bleeding of dye in the wash (there is less or none of that at the $50.00 price level).

5. With many companies promoting their "water-saving" denim manufacturing processes as eco-friendly, I can't believe they are pushing products which smell like a toxic waste stream at a chemical plant.


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## dicko1 (Oct 25, 2019)

Have you tried Oxy-clean? Its active ingredient is Sodium Percarbonate. When mixed with water it breaks down into hydrogen peroxide which is often used to remove the sulfur thiols in skunk spray.


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