Please think about how you are going to safely dispose of the waste solvent
before using it. Dumping it down the drain is not a solution if it goes out
into your septic system (and the environment) from there.
 Also as Paul stated many of these materials are carcinogens.  They are a
hazard to your health unless you have the proper protection.
As an alternative to solvents you might try putting a couple of the shells
in your freezer to see if that makes the plastic stiff enough to crack off.
I'll get off my soapbox now.
Beth DeHaas
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> From: Paul Monfils <[log in to unmask]>
> To: [log in to unmask]
> Subject: Re: [CONCH-L] another question on cleaning
> Date: Wednesday, July 29, 1998 12:35 PM
>
> YUCK!!  There seems to be no end to the challenging situations one can
> encounter under the general topic of "shell cleaning".  Detergents can
> do a good job of removing most oils, and it sounds like you have gone
> about as far as you can go with that approach.  Unfortunately,
> detergents are pretty useless when it comes to dissolving plastics.
> The problem here is that the term "plastic" encompasses a huge array
> of materials, with widely varying solubility characteristics.  For
> example, if you drop a styrofoam coffee cup (a type of plastic) into
> a container of a common hydrocarbon solvent like xylene or toluene,
> the cup will be gone (completely dissolved) in about 10 seconds.
> But, a piece of a plastic milk bottle dropped into the same solvents
> will sit there for weeks, with no apparent effect.  So, each kind of
> plastic is susceptible to certain solvents, and not to others.  Some
> plastics will dissolve in many different solvents, others in only a
> few.  So, the crucial question is "what kind of plastic are we
> dealing with?" - a question you probably have no way of answering, in
> this case.  Therefore, the only thing to do is to identify solvents
> that you can get your hands on, and which you know will not damage
> the shells themselves, and then try them.  In general, solvents that
> do not contain water are not likely to harm the shells.  Aqueous
> (water-based) solutions like ammonia, drain cleaners, bleaches,
> porcelain cleaners, oven cleaners, detergents, lye, etc. are not
> likely to have an effect on plastics, and some of them may contain
> substances which are destructive to shells.  Alcohols are non-aqueous
> solvents, and will not harm shells, but are unlikely to have much
> effect on plastics.  The best bet is a group of solvents known
> collectively as hydrocarbons (compounds composed totally or primarily
> of hydrogen and carbon).  Most solvents that will dissolve plastics
> are members of this group, and virtually none of these solvents will
> damage the calcium carbonate matrix or the pigments of shells.  Some
> non-aqueous solvents that are commonly available are:  charcoal
> lighter, cigarette lighter fluid, coleman lantern fuel, kerosene,
> gasoline, carbon tetrachloride (dry cleaning fluid), acetone
> (fingernail polish remover), paint thinners, paint removers
> (non-aqueous ones only), and mineral spirits.  All of these will
> dissolve some plastics.  None of them will dissolve all plastics.
> NOTE:  almost all of these substances are FLAMMABLE, and some of them
> are HIGHLY FLAMMABLE!  Vapors allowed to collect in an enclosed area
> can be EXPLOSIVE.  Also, the vapors of some of them areTOXIC to
> breathe.  They should be used only in a well ventilated area,
> preferably outdoors, and kept well away from all sources of flame,
> heat, and sparks.  That includes electric motors - no ventilation
> fans!  Nothing with an on-off switch, not even a light!  Not even a
> battery-powered light or fan!  A tiny spark from any such device
> could ignite the air-borne vapors of a flammable solvent.  And, some
> organic solvents can be absorbed into your body through your skin.
> Use appropriate protection, especially rubber gloves.  Even then,
> don't immerse your hands in the solvent - use forceps or some other
> sort of tool to place shells into, and remove them from the solvent.
> Careful - many solvents that dissolve plastics will also dissolve, or
> at least soften, various types of rubber (as in gloves).  Eye
> protection is recommended, just in  case of a splash.  See what fun
> shell cleaning can be?  Not to state the obvious, be careful about
> what kind of container you put the solvent into.  Glass is breakable,
> but is chemically resistant to organic solvents.  A metal container,
> preferably rust-resistant, would be a second choice.  A plastic pail
> is good IF the particular plastic the pail is made of is resistant to
> the particular solvent you are using!  Most plastic pails are
> resistant to most common organic solvents.
> If you have access to chemicals other than common household products,
> some of best plastic solvents are:  toluene (methylbenzene), xylene
> (dimethylbenzene), chloroform, tetrahydrofuran, carbon disulfide,
> petroleum ether, ethyl ether, benzene, amyl acetate, dichloroethane,
> dioxane, and methoxyethyl acetate.  Most of these will dissolve a
> wider range of plastics than the household products listed above.
> But again, none of them will dissolve all plastics.  Incidentally,
> most of these are also good solvents for paints, varnishes, laquers,
> waxes, oils, etc.  The solvents just listed have all the associated
> health hazards mentioned above - flammability, explosivity, toxicity,
> absorption through the skin, and in some cases to a considerably
> greater degree than the previously listed products.  Did I mention
> suffocating fumes and possible cancer hazards?  Don't attempt to use
> such chemicals unless you are experienced in their use, and have
> proper working conditions.  Here, where I work, that means an
> approved chemical fume hood, with flashproof lighting and other
> electrical components.  I want to provide some information here, but
> I don't want to encourage anyone to try something that might endanger
> their health - so please excercise extreme caution if you use any such
> materials, and if you don't know what precautions are called for with
> a particular solvent, don't use it!
> If you are not successful in removing the plastic from your shells,
> and if you consider the shells in question to be worth the effort,
> you could send me a few of the less desireable specimens (perhaps the
> ones with the heaviest coating of plastic), and I'll see if I can find
> something that will clean them up.  I have at least thirty or so
> organic solvents at my disposal that I can try.
> Regards,
> Paul M.