Wednesday, February 13, 2013

Why toolboxes and tool handles stink.

Tools with Cellulose Acetate Butyrate handles

For years I've encountered this issue, and it always perplexed me: why do a lot of toolboxes stink? I had always assumed it was related to heavy use with sweat and dirt and zero cleaning, but after I started encountering it on my own, barely used tools, I started looking into it. You can find some posts on DIY forums asking the same question, and how they could never clean the toolbox well enough to get rid of the stink.

Eventually I found someone who pointed out it was coming from the tool handles, and then they pointed out the culprit: tool handles made of Cellulose Acetate Butyrate. A thermoplastic, it offers excellent UV and solvent resistance that cellulose acetate doesn't offer. And it feels in the hand like a natural substance, something that is almost intangible, like a tool that is made by craftsmen, a characteristic that a polyethylene or polypropylene handle does not have. CAB also offers no splinters like the older wood handles. It also can be very clear. And when that plastic begins to degrade, it releases free acetic acid and butyric acid.

The odor of vinegar is a familiar sign to those in the film and photographic business; the cellulose acetate backing of film releases it as it degrades. I once visited a famous photographer's house and his office where he stored his negatives had that acrid odor--while for a photographer it reminds you of the darkroom, the midpoint of the creative process, it also brings to you vividly the end of the process--the decay of the work.

The butyric acid, one of the carboxylic acids, with a formula of CH3CH2CH2COOH, just smells like, in polite company like parmesan cheese, or like rancid butter or vomit. It's not nice above a certain concentration. Once I discovered this I immediately spent a little time sniffing each tool I had, and in short order discovered the ones that are the problem. They immediately got isolated from the rest, because the free butyric acid really does migrate and make everything unpleasant. I thought about giving the tools away, but really, who wants such a tool, even if free? I was going to throw them out, but that made me feel bad. And I think I've found a solution to stinky tools. I carefully fully coated the handles in two coats of shellac, a natural sealer, and now they don't smell to my nose.


Anonymous said...

Thank you so much for the info. We've been so puzzled by our stinky tool box. Your article is well written as well, btw. Thanks.

Anonymous said...

It took me a long time to check this out on the web, because I was certain it was something we did. I thought someone had spilled some toxic substance on the tools, or used them to mix something smelly. I had only just figured out, through the process of elimination, that it was the plastic handled screwdrivers. What in the hell!!?? We can put a man on the moon, etc. etc. Is this really necessary? Can we just get wood handles, or some other damn thing that doesn't smell, and let us get back to work without this LUNACY driving us crazy? Another ill effect of the space-age, let's get back to what we know works and won't hurt us, I don't need shiny objects, just tools that work and don't annoy.

Anonymous said...

So, now that we have identified the culprit, how do we neutralize the smell?

1. in the toolbox
2. on the metal tools
3. on the wooden and non-stink plastic handles
4. on the stinky plastic handles

Dean W. Armstrong said...

I am at a loss as to why this comment was removed:
Anonymous has left a new comment on your post "Why toolboxes and tool handles stink.":

So, now that we have identified the culprit, how do we neutralize the smell?

1. in the toolbox
2. on the metal tools
3. on the wooden and non-stink plastic handles
4. on the stinky plastic handles

Dean W. Armstrong said...

4. I've read that if you convert butyric acid by neutralization via sodium bicarbonate into sodium butryate it becomes non-stinking. But I've not tried it.

1, 2, 3: separation, extra cleaning, sunlight, and perhaps sodium bicarbonate. Once I removed the smelly items I cleaned the toolbox with a variety of cleaners to reduce the smell, but it really was the removal and sealing of the decomposing tool handles that stopped and started reducing the smell factor.

Anonymous said...

In the toolbox I tried Boraxo. Meh.

I tried spraying a metal tool with an old can of Gumout. It smells too strongly. so I wiped all the non-plastic tools with some Liquid Wrench (mind you, these are just some old things hanging around, and hence free).

I will try the sodium bicarb on the plastic handles. For now, I have wrapped the stinking tools in cloth and no longer store them in the old place. In fact, I wonder if I simply store them in an open basket, wrapped in cloth, they would stink less.

(I was the anonymous whose post was deleted)

Anonymous said...

I have the same issue with an old "coin Dealer" Briefcase, it holds 4 custom plastic trays which display coins under a clear plexi-glass cover which reek like vomit. It was made in the 80's and for a coin dealer to transport several trays of coins to a show. I'd like to use the trays, as they are great for displaying coins, and was thinking of coating with some type of paint or sealer to make them airtight. I read on another forum someone suggested Armor-all. I'm soaking them in my kitchen sink now in white vinegar and water and it seems to be working a little bit.

Matte said...

Old pinball platic parts from the 70-80's stinks the same! Bally and Gottlieb and possible Williams....I have a large box of replacement plastics for these pinballs and the bad odour of vomit reaches my nose every time I come near it! :( And I also have a set of Xcelite screwdrivers from 1985 (!) which still stinks to high heaven! (and always have) I have them in a small toolbox and everytime I open it I'm about to p*ke myself...gah!

I will now leave these screwdrivers in the sun for a week and probably coat them with some
clear laquer afterwards. Many thanks for the tip! :)

danny kujawski said...

I took mine back to Sears. they were replaced even though they were twenty years old.

xvlly said...

I noticed some older tools in an unused box smelling. I like the older tool. They were still around after others got broken, lost or stolen--ahem...borrowed and forgotten.
Try this.
You know those little bags of moisture absorbing crystals that say "don't eat" that come in the packaging for shoes and anything shipped from overseas? They absorb moisture. The also seem to keep my tools from rusting and stinking. (they work great in a camera bag to.)
I think it is called desiccant and as long as you remember not to eat it they last a really long time.

Anonymous said...

I don't know if my chemistry is correct, but I figured I could oxidize the butyric acid with something. So, I tried soaking in Oxyclean detergent/ stain remover for a couple of days. It seems to have worked, so far. I'll see how long it takes to come back. I used the powder that has some blue crystals in it. It also works for removing moss from our north facing asphalt roof. I also used it to get rid of the similar stink from old polyurethane waterproofing on fabric.

Tahlia Merrill said...

This is VERY useful, and I'll probably have to replace all the tools I have with CAB, but when I go to buy new ones on amazon, I have no clue how to find ones without CAB. Looks like Craftsman brand is infamous for this problem--any recommendations for non-stinky brands?

I'll have to give Anonymous' oxyclean idea a try. A little worried about leaving the metal tools in water for several days. Won't they rust?

Dean W. Armstrong said...

That's a good question, as I've never seen handles described beyond "durable" and 'easy grip". Every CAB handle I've seen is either transparent with a dye color, or transparent with 50% painted. Klein Tools describes their handles as "tough plastic", which could mean anything, but they look just like other CAB (and they used it in the past).

I have what I suspect is a CAB screwdriver at work, but it was purchased new and is probably about 10 years old, and does not smell. Some CAB handles from the early nineties do smell, and I suspect if you bought new CAB handles now, you would have some time before they degraded, especially if kept in a cooler environment.

The Oxyclean thing I would hazard might be the conversion into a butyrate salt, as it is a basic solution, however I now see that sodium butyrate is listed as having "an unpleasant smell".

Keeping the metal out of the solution would be the way to go, perhaps keeping them vertical in the solution.

itsiceguy chris said...

I dipped all my screw driver handles in clear satin lacquer hope that will help

Jeremy said...


Did the clear lacquer take care of the smell? I was thinking about dipping mine in polyurethane.

Anonymous said...

CAB has not been used in tool handles since the 80s All the manufacturers are aware of the problem and stopped using it. My question is what is the best topcoat.I recently cleaned up a whole bunch of Xcelite nut and screw drivers. Shellac is neither water proof, alcohol resistant or durable. I have heard clear nail polish advocated but that is lacquer, another less than durable product. I have to be careful not to use something that dissolves CAB. Moisture cured or catylized polyurethane is what i have been toying with, though the single part stuff might be enough.

Ryan said...

I know the exact distinct smell you are describing, and I have no problem understanding why it may be offensive to many people, but I am glad it does not offend me. Personally, it's more nostalgic to me, reminds me of my father's tools, so I don't feel the need to mask it from my own tools that now have that particular scent.

Frank said...

I only have a few tools with CAB from my father so my toolbox is not bad. My toolbox at work however smells like nothing else which is full of old Xcelite sets past on from others. I was thinking you could use a spray epoxy but then it would react with acetone. I think the best choice is product called plastic- dip which is a latex base product that forms a rubberized handle on the tool. If you have a latex allergy, you should try something else. If my box gets intolerable, I will use the plastic-dip since It should improve the grip of the handles.