Screwdriver Fungus

I've seen the same thing here in Iowa. I attribute it to engine oil, skin oil that feeds the fungus. The plastic surface may contribute, but I've only seen it on drivers that have been used vs. brand new and sitting in the same location. It's on screwdrivers parked in a tool drawer type box (i.e. open to the air in the room), that sits in relative high humidity and dark. I don't see this in my machine shop that I keep dehumidified.

I doubt that it could be a fungus, but it could be a lichen. Photo would help.

Dried white material on my own screwdrivers is always assumed to be paint spatter.

Wipe your tools down with WD40 or similar after usage maybe. See if that fixes it. It will help protect the metal parts as well and as far as I am aware, not affect the plastic parts, except to stop that "fungus".

Or use Gun oil for that really great smell maybe?

Or possibly use the tools more often?

My first thought was that someone who had used the screwdrivers had paint on their hands, and white is the most common color for interior house paint.

I have noticed a funky odor on my old mechanic's tools, but without any white residue. I attributed it to some kind of decomposition of the crud that results from motor-oil film mixing with road dust, which gets transfered into the inscribed labels on the tools. And I have seen a white residue on screwdriver handles, but I assumed it was paint, especially since it didn't occur on MY tools, but on other people's tools. Some people are very messy painters, and screwdrivers are many people's go-to tools for opening paint cans and banging them shut later. Could the white residue be paint, with the funky odor resulting from other uses of the screwdrivers on cars? See if your wrenches have the same odor without the residue.

My first thought was to tell you to move to Nevada, where it was drier. My memory, however, was that this happened there also. I remember it most when I was living in Georgia and Alabama. I believe it is a function of residue from your hands while working. I just looked at my screwdrivers and the ones, (mostly craftsman) that I use frequently in New Mexico (high, dry, cool) have some of this residue, however the ones that I almost never use have none. This still does not tell me whether the residue is from a reaction of the plastic with oils from hands or whether the chemicals in the plastic are coming to the surface because of use. I do have an old screwdriver of my dad's that shows no problems with the handle other than the white residue. It was probably made in the late 40's or early 50's and looks to be of the same material. I just looked at all my metal tools and saw no residue.

I have noticed this also. I have several screwdrivers that I inherited along with the ones I bought for myself. Most are Craftsman but some are not. I live in CT, Warm and humid in the summer months. Cold and dry in the winter. I have found that it is on the tools that I do not use as often. I always thought it was a mold or fungus. It does scrap off but eventually returns.

I found a discussion that answers this mystery:

http://bbs.homeshopmachinist.net/threads/50519-Mold-or-Goo-on-long-term-storage-screwdriver-handles-Whatizzit

"It's the plasticizer migrating to the surface as the plastic degrades and smells like vomit."

"The stinky plastic is CAB=Celluouse Acetate Butyrate. It always outgases, and is noticable in confined spaces. "

Yes, it does resemble vomit, and yes, the two tools I cleaned up this week were both craftsman. It doesn't really resemble anything alive, and after it is cleaned off has no sign of any deterioration of the plastic.

If it is simply the plasticizer, then why are my screwdriver that I use most often coated and none of the ones that just lay in my box affected? I could make a case that it is the plasticizer, but it requires that something else is affecting the handles in addition.

That's the opposite from what I (and others) have experienced. I've never seen this happen to often used tools, just those that have been idle for a while.

I am well familiar with plasticizers. Some migrate out on their own. Some with heat. My screwdrivers are all quite old. Most from the 60's or earlier. It may be a different plastic and plasticcizer than newer tools or mine may have lost much of their plasticizer. One more thing is that I have never smelled the odor that some reported on the old tools. I did have a bad smell on a set of cheap screwdrivers from China that I was going to dedicate to my camper. I threw then away. They were also bad metal and broke easily.

Remember when foreign cars were first imported to the USA in volume?

The windshields all fogged up on the inside due to plasticizer evaporation from the vinyl dashboards. Especially in hot climates.

Same thing. There are better materials for these applications, but they cost more.

A plastic screwdriver handle requires mechanical strength to hold the tool bit and therefore, it is unlikely that a plasticiser would be added. Plasticisers are usually used to make a plastic flexible

With a new plastic handle, its surface will have a very thin 'skin' that acts as a seal formed by the moulding process. This is the plastic material that was in immediate contact with the hot metal mould. This seal may temporarily help to preserve its new shiny look and impede leaching slightly when not worn away.

New plastic products do age and deteriorate eventually even when stored in the dark and the main cause is oxidation despite the compounding with antioxidants.

I believe that some plasticizer may be present, even in the more rigid types of thermoplastics. CAB indeed has a distinctive odor and likely some form of plasticizer.

Not sure there's a lot of technical support for your "skin" theory either. The outer plastic surface will indeed take on the texture, or smoothness, of the mold surface, but thermoplastics, being homogeneous, don't skin over if molded properly.

At least that's how I see it.

Perhaps you are referring to process aids.

CAB can be processed as a thermoplastic and depending on grade is compounded with a plasticiser.

The skin effect is an inherent result of some polymer processes. As for theory, you can find academic papers documenting the skin effect of thermoplastics. For the, 'proper moulding' of thermoplastics, some design and process guides published by resin producers and suppliers also discuss the formation of skin and the ratio of skin to core.

Perhaps I am not as well schooled in the art of molding as you, but the only time I have ever encountered a skin vs core ratio is in the molding of foamed thermoplastics.

If you use a screwdriver as a chisel, pounding on the end, the end is likely to mushroom out. This is another species of screwdriver fungus. ξ