Plastic

[Martinini]

A pair of surgical scissors can reduce most plastic containers to a storable state in short order, or as a last resort cut into a size legal to dispose of overboard. I prefer to cut into flat pieces that take up little room and dispose of when hitting next destination. Rinsing in sea water eliminates odor from rotting foodstuffs left behind in container after use,and do it before cutting down.

[Robertcateran]

Originally Posted by GordMay

On an industrial scale, and with industrial incinerators, it might be ok to burn plastics.

However, open beach fires, barrels or even wood stoves, do not reach high enough temperatures (min. 1,800 deg. F, or 982 C) to destroy many of the dangerous chemicals created when plastic burns.
Plastics (particularly PVC) result in emissions of chlorine, heavy metals, carbon monoxide, furans, and dioxins (tetrachloro-dibenzo-dioxin.) when burned.

I would NOT stand anywhere near the fire, and breathe the fumes.

See also:
"Is Combustion of Plastics Desirable?" ~ by Bruce Piasecki, David Rainey, Kevin Fletcher
Is Combustion of Plastics Desirable? » American Scientist

I agree very much with what you say Gord, but unfortunately in many places the plastic bags end up blowing away and into the marine environment. I very much endorse what you say about the halogenated hydrocarbons such as PVC and teflon leading to the production of long term accumulative nasties such as dioxins, but these are generally hard plastics that don't cause such havoc in the oceans and are less likely to blow around. Definitely don't burn these. I hear that in some countries they are banned outright because of the difficulties in disposal of them. For getting rid of polyethylene plastic bags where there is no suitable landfill, the fumes that come from burning are noxious in the short term so definitely don't inhale the fumes, but they are generally biodegradeable. The heavy metal concentrations of these plastics has been greatly reduced over the years with better catalysts. Melting them into a solid mass and burying them is probably the best means of disposing them in out of the way places.
Again, to get things in perspective, it might be worth checking out the quantities of dioxins produced in a coastal heath fire. Here you have the ring structured hydrocarbons from the anti-insect and anti-rot chemicals produced by the plant with chlorine from the salt spray. This is a nice recipe for producing chlorinated ring structured chemicals such as dioxins.
Dioxins are also produced in the bleaching of paper. There is presently a stink in Tasmania over a potential pulp mill, partly because of the problems of disposal of the waste from the bleaching process. It is cheaper to use chlorine bleach than peroxide bleach. For that matter, every time you use chlorine bleach on organic matter there is a fair chance of producing dioxins.
CLeaned plastic bags can certainly be stored in a very small volume if suitably compressed or melted, so I end to agree, that rather than burying them in a place with limited land fill opportunities such as on a small coral attol, it is better to take them back to some mainland area to bury them.

I still have no objection to remelting them into useful items

[Robertcateran]

Originally Posted by delmarrey

Why not just crush it into heavy bundles, sink it to the bottom of deep seas and let the barnacles take care of it. Barnacles seem to take care of the bottom of plastic boats fairly well.

Unfortunately they usually don't sink, can become uncompressed and we don't really know what is going to happen to them on the bottom of the ocean. Barnacles enjoy the substrate of a plastic boat because it is just near the surface and this is where they like to live. They do nothing in the way of breaking down the plastics

[MidLandOne]

Originally Posted by Martinini

A pair of surgical scissors can reduce most plastic containers to a storable state in short order, or as a last resort cut into a size legal to dispose of overboard.

I wouldn't advertise too much that you discharge it overboard if I were you.

For boats under the flag of or domaciled in any country that has enacted the MARPOL Convention (or equivalent requirements) into its own legislation, so that means for most if not all of us, it is totally prohibited to discharge any form of plastic into the sea no matter how small and no matter where we are in the world.

[Martinini]

Never said I did or would, just that some non signatory flagged vessels might have that option. And of course any GOVERNMENT owned vessel is exempt from all the rules and can dump anything they want if they so desire!! Just read that clause in the Convention. So any Navy vessel from any country can roar around steaming black smoke and chunking anything they want overboard! Ain't life fair!

[lookoutnw]

Solar oven and it will melt it to a small lump. Add to teh small lumps you already have, it will just give you a reason to stop at that village and get some ice cream. I am always looking for a reason for ice cream or shaved ice runs....

[Robertcateran]

Originally Posted by lookoutnw

Solar oven and it will melt it to a small lump. Add to teh small lumps you already have, it will just give you a reason to stop at that village and get some ice cream. I am always looking for a reason for ice cream or shaved ice runs....

Excellent suggestion for compacting non halogenated plastics.

[MidLandOne]

Originally Posted by Martinini

And of course any GOVERNMENT owned vessel is exempt from all the rules and can dump anything they want if they so desire!! Just read that clause in the Convention. So any Navy vessel from any country can roar around steaming black smoke and chunking anything they want overboard! Ain't life fair!

I think you will find that it is common practice for governments to enact MARPOL V requiring ALL vessels under its flag and in its navy to comply with the garbage rules. Certainly both my own country and the USA do so.

So maybe life is fairer than you think it is and reality is different to that constructed by your imagination .

[Martinini]

Of course they do, our governments Always do the right thing!!!
But enough of this, MARPOL is a good thing even if it can be an annoyance sometimes. We all have to try and keep our Oceans clean as possible for ourselves and our childrens children!!

[S/V Antares]

Like Martinini we cut the plastics into small pieces after rinsing. We line a small cooler with a plastic garbage bag and compress the stuff with our foot. Close up the bag and it becomes a solid block much like the vaccum packed bricks of coffee. Several months worth compress into a shoebox size.

[Bill_E]

Interesting discussion. I'll reiterate a lot of the things that have been said and perhaps add a few. First, burning chlorinated plastics (PVC is really the only one that is common enough to worry about) is a bad deal because of the dioxins and HCl that are produced. Definitely don't stand over a fire of chlorinated plastics. Actually, I should say don't burn PVC at all! Burning teflon is even worse, but it's pretty hard to get it to burn, even when mixed with other flammables. There was a bunch of research done on the toxicology of teflon in the 70s and 80s at the National Bureau of Standards, mostly because of fire related deaths especially when the MGM Grand in Las Vegas burned. Anyway, fumes from teflon burning are more toxic than any other polymer.
Incomplete combustion of any organic compound will produce pollutants, many of which are carcinogenic or teratogenic. And, most fires are incomplete combustion.
And then we get to the issue of CO2 and global warming. All combusion of organics produces CO2. But if you put organics in a landfill and bacteria break them down, the product is CO2. But that goes for paper bags and cardboard as well. Another question is: How do the local disposal agencies take care of waste? They could be at least as bad as individual cruisers making little fires.
For me, the best I can do is to minimize packing material and then make sure that whatever is left doesn't end up in the ocean. When you see articles about the Great Pacific Garbage Patch (The World's Largest Dump: The Great Pacific Garbage Patch | Ocean | DISCOVER Magazine) it makes me think that burning isn't such a bad idea.

Bill

[MidLandOne]

What is the toxicity of the combustion products from burning polycarbonate which I am told is used for many drink containing bottles (but I have never checked if that is so)?

John

[MidLandOne]

Originally Posted by MidLandOne

What is the toxicity of the combustion products from burning polycarbonate which I am told is used for many drink containing bottles (but I have never checked if that is so)?

Someone on a forum must have mentioned the polycarbonate for soda bottles because it is wrong, wrong, wrong . Just some non disposable bottles use it.

Checking for myself I find they are much more sensibly made from polyethylene terephthalate (PET).

So, starting again - what is the toxicity of the combustion products from burning PET?

[Robertcateran]

Complete combustion would give carbon dioxide and water. Incomplete can give lots of interesting chemicals -many of them toxic short term, but biodegradeable. On a beach, with Na Cl can provide the chlorine to make some longer term nasties. Wood also gives many of the same compounds when poorly combusted. Don't breath in smoke of any type. Better to simply melt PET into a lump or chop it up into easily stored pieces and store it for later burial or recycling

[GordMay]

Originally Posted by wlearl

... Incomplete combustion of any organic compound will produce pollutants, many of which are carcinogenic or teratogenic. And, most fires are incomplete combustion ... Bill

Originally Posted by MidLandOne

... what is the toxicity of the combustion products from burning PET?

The COMPLETE combustion of PolyEthylene Terephthalate (PET), such as in a modern waste to energy incinerator, are Water & Carbon Dioxide.
Complete combustion requires high levels (enriched) of oxygen and very high temperatures.
The INCOMPLETE combustion, much more likely in any fire a cruiser might utilize, include Carbon Monoxide, ethylene glycol, aldehydes and other Carbon, Hydrogen, and Oxygen compounds, varying in chemical structure and molecular weights.
In actual use "plastics" are usually "formulated" products, containing pigments, and various other additives, that can have varying levels of toxicity.
PET plastics are essentially inert, when sequestered in landfills.