I bought some mothballs advertised as ‘naphthalene balls’ a few weeks ago, aware that there’s a lot of conflation of terms on OTC chemicals, due
to eco-substitutes and such like. Anyway, this one (‘Whale Brand Naphthalene balls’) at least explicitly used naphthalene in its name.
Today I wanted to verify whether this product is indeed actually naphthalene, by rough MP determination. I have to say also that the mothballs do indeed smell like mothballs (although I haven’t smelled
mothballs in years and years) but that I seem to remember something a little softer and waxier than what I bought.
To avoid smelling out the lab I ran the MP test under medium kerosene. Naphthalene has an MP of 80C but no melting occurred, not even pushing the
temperature to about 110C and holding it there. No perceptible dissolution of the product into the kerosene either. I wanted to push the temperature
higher but around 110C heavy refluxing started and I had to stop the experiment.
Reading the plastic wrapper it also stated ‘ingredients…….complex camphor’. Actual camphor is quite a different compound but it appears also to be used as a moth repellent. Its melting point is about 176C. I haven’t tried
melting it yet w/o kerosene cover.
Has anyone had a similar experience with moth balls? Magic Muzzlet - 24-1-2011 at 14:30
The issue could have been avoided by reading the wrapper in the first place? It just seems obvious you should check these things, read msds before
buying the product of interest. But I'm sure you know that. Anyway, I have not bought mothballs for naphthalene so no I haven't had any similar
experience myself..ScienceSquirrel - 24-1-2011 at 14:37
We have moth balls made out of naphthalene where I live.
They have a distinctive smell and look like that they have been pressed together out of crystals.
Breaking up a ball and doing a melting point test on a little of the fine powder in a capillary tube results in a spot on melting point.
Naphthalene is still used for preserving fur and feathers for fly fishing and the like.
Try this supplier; http://cgi.ebay.co.uk/Moth-Balls-Original-99-Pure-Naphthalen... psychokinetic - 24-1-2011 at 16:46
My mothballs say naphthalene, but I'm sceptical.blogfast25 - 25-1-2011 at 08:27
The issue could have been avoided by reading the wrapper in the first place? It just seems obvious you should check these things, read msds before
buying the product of interest. But I'm sure you know that. Anyway, I have not bought mothballs for naphthalene so no I haven't had any similar
experience myself..
‘Naphthalene balls’ is now a common term that can cover multiple types of products. Very often the vendor is clueless as to the chemical
composition of the sold product. As regards the MSDS, I searched for it and couldn’t find one. The product was bought from eBay: there you can’t
read the wrapper, only the vendor’s description.
But even ‘complex camphor’ doesn’t necessarily mean it’s camphor or camphor based. Even if the product is camphor based (as I now suspect) it
tries to mimick the old style naphthalene balls in all respects, including physical form.blogfast25 - 25-1-2011 at 08:29
Thanks sciencesquirrel for the suggestion but I think I'll consult my local hardware store first and see if I can get an MSDS for any product on offer
that claims to be naphthalene...
[Edited on 25-1-2011 by blogfast25]Arthur Dent - 25-1-2011 at 10:02
Even if the product is camphor based (as I now suspect) it tries to mimick the old style naphthalene balls in all respects, including physical form.
Surprising in some way, because isn't camphor much more expensive and hard to synthetize than naphtalene?
At various drugstores and groceries 'round my area, camphor is always more pricey. I wonder why naphtalene wouldn't be prefered for mothballs instead
of camphor...
Robert ScienceSquirrel - 25-1-2011 at 10:27
Camphor is fairly easily synthesised from alpha pinene which can be extracted from turpentine and some camphor is a natural product extracted from the
camphor tree. Naphthalene is extracted from coal tar.
I suppose it could be said that the smell of camphor is more pleasant, it is less toxic and it is not a suspected carcinogen like naphthalene.
Most people will not suffer ill effects as the level of exposure is so low but the perceived risk might make people prefer camphor.
I bought the Whale brand mothballs on ebay on the promise that they 'contained napthalene' - the seller didnt mention the lack of actual napthalene!
I only realised this when they arrived and read the back of the packet! Thanks blogfast25 for the confirmation of my suspicions!zed - 2-10-2012 at 14:22
Synthesize Camphor? Why?
Camphor is a major product of the Camphor Tree. It is found in the wood of mature trees, and it is liberated via steam distillation of chipped
wood. The end product isn't very expensive, and it seems to be pretty effective at moth control. Though I find Red Cedar Chips very effective too.
As a side note, after the Camphor has been crystallized out of the distillate, and other products removed, the residual "Brown Camphor Oil" is the
source of much of the world's supply of Safrole.
The trees grow wild in parts of Southern California and Florida. In some areas they are considered a non-native, invasive, "pest" species.
Last time I bought moth balls, they were indeed Napthalene. They were inexpensive, and I got them at my local Fred Meyers store, in Portland.
Probably about five years ago.
Back in the Seventies, "Moth Balls", meant Para-DiChloro-Benzene. Don't think they do it that way anymore. Maybe folks became concerned when all of
those two-headed babies were born, or perhaps it was all of the birds dying.
[Edited on 2-10-2012 by zed]UnintentionalChaos - 2-10-2012 at 18:06
Back in the Seventies, "Moth Balls", meant Para-DiChloro-Benzene. Don't think they do it that way anymore. Maybe folks became concerned when all of
those two-headed babies were born, or perhaps it was all of the birds dying.
You can certainly still buy p-dichlorobenzene quite easily (at least where I am in the eastern US). I have about a kilo of it that I bought as "moth
ice crystals" and they sell it as balls too. Pucks of the stuff are in most urinals, as well. Of course, I have yet to do anything with my
supply...it's just not terribly useful.Hexavalent - 3-10-2012 at 10:19
Speaking of napthalene, could it be hydrogenated to yield tetrahydronapthalene?Lambda-Eyde - 3-10-2012 at 10:50
Yes. There is a discussion about it in the potassium from KOH+Mg thread IIRC. It has also been discussed earlier, UTFSE.Endimion17 - 3-10-2012 at 13:45
Naphtalene has become next to impossible to find in most of Europe, especially EU.
I've got a small sample I've purified from some ancient mothballs. It was naphtalene and magnesium sulphate, now it's naphtalene flakes. The sample is
too small to do anything useful with it. It's just a part of my collection.
So, UnintentionalChaos, you say that urinal pucks are p-dichlorbenzene? Interesting. But then again, they do look as a relatively pure compound.UnintentionalChaos - 3-10-2012 at 14:55
I saw some 90% naphthalene, which was sold as 'naphthalene flakes' under a generic brand.
How would you go about purifying it, the contaniments are not listed? Sorry if it has been already posted, if so can you please link it.ScienceSquirrel - 8-10-2012 at 02:53
You could try crystallising it from a suitable solvent like petroleum ether, sublimation under vacuum or zone melting.
I used to use carbon tetrachloride for the crystallisation and that worked beautifully.borrowedlawyer - 8-10-2012 at 02:59
You could try crystallising it from a suitable solvent like petroleum ether, sublimation under vacuum or zone melting.
I used to use carbon tetrachloride for the crystallisation and that worked beautifully.
Thanks for the quick reply, around here carbon tetrachloride is rather hard to get a hold of for environmental concerns (I think!). I'll try and get
some petroleum ether, but I am not really sure about which boiling point one I should get.
CheersScienceSquirrel - 8-10-2012 at 05:11
Up until the late seventies you could buy carbon tetrachloride and 111- trichloroethane off the shelf in chemists, shoe shops etc for oil spot
removal, etc.Vargouille - 8-10-2012 at 14:22
I would get several boiling ranges of petroleum ether, for different purposes. The 40-60C range is useful for recrystallizations, and higher boiling
ranges can obviously withstand higher reaction temperatures. The high-boiling ethers are also good for occasions where the high vapor pressure of the
40-60C range is not recommendable. It really depends on your reaction. My organic chemistry book doesn't mention recrystallization of naphthalene with
petroleum ether, and I don't have the experience of testing the viability of using different cuts of petroleum ether to recrystallize, unfortunately.
My best guess would be to try the 40-60C cut or the 60-80C cut. elementcollector1 - 9-10-2012 at 20:13
My napthalene says 'contains napthalene' or something of the sort all over the package, and has the white, crystalline balls inside. Should I be
skeptical?ScienceSquirrel - 10-10-2012 at 03:09
I would break a piece off one, grind it up and do a melting point, it sounds pretty pure to me.
