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Epoxy and Vinylester Toxicity

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Hey everyone,

ResearchIng a new canoe buy and looks like these composite canoes use some interesting chemical components in their construction. While it seems that the builders are most at risk and need to be most aware, curious if anyone has any input on the least toxic of the two options for the user of the canoe and the environment? Or would your take be that after curing one or the other (or both) are “inert”? Thanks!
 
I have used a variety of epoxy resins. Epoxy is not very toxic in the usual sense of the word, but the hardeners tend to be allergenic and repeated skin exposure to the hardeners used in epoxies can cause some nasty allergic contact dermatitis. One thing I have noticed with West Systems G Flex epoxy in particular is that the hardener tend to give off vapors that cause eye irritation.

Vinylester and polyester resins use methyl ethyl ketone peroxidase (MEKP) usually as a catalyst. You don't want to get any of that stuff in your eyes as it is corrosive and can cause severe damage. Polyester resins in particular release styrene vapors which are irritating to mucous membranes. That is not usually an issue for the backyard canoe repair guy using those products outdoors, but if you are working on the interior of a decked boat with those products you should use a respirator.

Once epoxy is fully cured I do not believe that it releases anything that could be described as toxic. But most composite canoes tend to be gel coated so the exterior of the hull is usually a polyester material. Your question is somewhat moot because most all manufacturers of quality composite canoes use vinylester resins these days, for a variety of reasons, although a few may still use epoxy.
 
Once cured, I would think any of them would be completely inert and harmless to both the paddler and the world at large. If you want to minimize environmental impact, take care of the canoe. None of those materials break down readily in landfills and one can only have so many bookshelves.
 
"Once epoxy is fully cured I do not believe that it releases anything that could be described as toxic. But most composite canoes tend to be gel coated so the exterior of the hull is usually a polyester material."

I mostly agree with this, with one caveat, and that is I don't know the full formulation of these resins. There could be plasticizers or other things in them. However, I have no doubt that compared to things like the interior of your car a finished canoe is harmless. I worry more about clothing, which is full of all kinds of yummy chemicals besides the base polymer and touches your skin all day.

I would not recommend repurposing any product for food use that was not intended for it. Meaning use your old canoe for a bookshelf, not for lightweight camping plates.

Gamma1214 mentioned the pollution comes from production of the canoe, and they cannot be recycled. I would pick the best canoe for my intended use, and take care of it both on and off the river.

The canoe is really dangerous given its intended use is around water. If you are new to paddling I suggest joining a local club, always wearing your PDF, and practicing self-rescue.
 
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Thanks everyone and some great input for sure. I definitely am one to read the label and I try to avoid said “mutinates” if I can, @Alasgun !

@pblanc there are actually several manufacturers I’ve been checking out that use epoxy. However reading through the data sheets on either epoxy or vinylesters I’m seeing known carcinogens listed and chemicals that are toxic to aquatic life and so on - prefer to keep my distance from such chemicals for various reasons.

I see some are out there that do say they’re safer once cured (example safe for food contact - and no, won’t be eating off the canoe) but at least at this time haven’t found any canoe manufacturers known to be using any of the products rated in this manner.

That said short of building my own birch bark canoe might be tough going in the canoe market. :)
 
All epoxies, as far as I know, are considered food safe once cured. They're commonly used as table/bar/counter top finishes.

That's not to say there can't be environmental concerns in all other parts of the process but I think there is no health concern whatsoever about coming into repeated contact with a composite, or any other plastic, canoe.

Alan
 
All epoxies, as far as I know, are considered food safe once cured. They're commonly used as table/bar/counter top finishes.

That's not to say there can't be environmental concerns in all other parts of the process but I think there is no health concern whatsoever about coming into repeated contact with a composite, or any other plastic, canoe.

Alan
Even if the base resin is food safe the kevlar, carbon fiber, mold release, and colorants are all suspect. Unless a manufacturer labels a product is food safe it's good to assume it's not.

But that doesn't matter for a canoe, unless you are using it as a punch bowl, or a fermentation vessel.
 
If you are really concerned about toxicity then you may want to consider a wood and canvas canoe. These probably require fewer toxic things than any plastic canoe. The first link below has list of builders if you aren't sure where to look.

Bark canoes are likely to be the least toxic option and there are a number of people still building them too. The cost goes up substantially though. The prices per foot commonly range from about $200 to well over $1000.

If your concern is more about the environmental carbon footprint then the second link below to a recent discussion in the wooden boat forum may interest you. Good luck and let us know what you decide.

Benson




 
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Thanks, I had honestly not seriously considered those canoes of alternative / traditional materials so I will do some research there to see if it’s workable.

@Alan Gage it would appear that there are some epoxies out there rated for food contact (and vinylesters, I think) but none are used in canoe construction that I have found at least so far - have had a couple epoxy manufacturers (brands mentioned by canoe manufacturers) relay a “no” so far. Not that food rated is by any means needed, but at least in my mind, that would have a product trending towards being a safer product all around (safer for people / environmental contact).

That said, not sure what levels of exposure during use and maintenance, and to the environment, there would be for either product after initial curing / if one is better in that regard.
 
I'll only suggest that I'm sure my drives to an entry point represent a much greater hazard than the epoxy in my Souris River Tranquility ever will, especially with the coats of spar varnish on it.
 
That said, not sure what levels of exposure during use and maintenance, and to the environment, there would be for either product after initial curing / if one is better in that regard.

Since you'll presumably be wearing clothing while paddling, and you'll be sitting on the seat rather than in direct contact with the hull, not to mention the fact that you probably won't be canoeing daily, I think it's pretty safe to say that any exposure to an inert plastic should be much less of a concern than all the other daily contacts made with plastics and chemicals.

Alan
 
Thanks - I definitely try to take care in what I buy in day to day life as well, not just canoes. Is it inert once cured, however? The chemicals going into both are quite rough. What I’m trying to determine is not the risks compared to anything else, but the risks of the (cured) products themselves, if any - both for people and the environment. And in the case that there are risks, if one is less risky (more inert) than the other (epoxy or vinylester).
 
So the initial question was about personal exposure. As a chemist whose employment is related to these questions* I agree with the sentiment that canoes do not pose an meaningful chemical exposure risk to the user.

The environmental risk is much more difficult to assess. First you'd have to understand the materials well enough to understand the environmental cost of manufacturing. That is difficult because the ingredients and processes are not readily available or understood. More importantly the individual companies practices will have a massive impact on the environmental footprint.

I think Jabberwocky has a good point about environmental impact statements. If I had to pick between new composite canoes based on an environmental factor I would ask about waste management and employee safety measures.

*I don't work with epoxies or vinylester, so I don't know if one is cleaner than the other. I worked with other plastics in medical products for 10+ years.
 
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If you ask me to pick the environmentally cleanest and chemically safest canoe I would probably find a used aluminum canoe nearby. Used as a canoe (not fermentation vessel) it's chemically inert.

Used aluminum canoes are cheap and readily available, so would add little demand for new products. They are also easy to recycle.
 
I was a boat builder in Arlington, WA building Tanzer Yachts in the 1970s. We used vinlyester resins which have plenty of fumes. MEK as pblanc mentioned is one of the worst offenders. I never liked using vinylester resins. We washed our hands in acetone often before we knew how dangerous it is.

I have repaired plenty of canoes since and switched over to epoxy exclusively. It has little in the way of fumes and is very strong. I built a Pygmy sea kayak from a kit with epoxy in my house. The room was closed off and had plenty of good windows for ventilation. Epoxy costs more but is worth the extra money.
 
if one is less risky (more inert) than the other (epoxy or vinylester).

Alright, my first post here. Some inflatables are made of rubber, not PVC.

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By themselves in liquid and gaseous form, vinylester seems to be more toxic than epoxy. According to their Safety Data Sheets, which can be found on THIS SITE, vinylester is classified by OSHA as a hazardous material and has warnings about potential carcinogenic and toxic environmental effects. Epoxy doesn't seem to have as extreme warnings. Sweet Composites, a long-time supplier of canoe building materials, does not sell vinylester or polyester resins but does sell epoxy.

That said, I don't know of many commercial boat builders who use epoxy, probably because of its expense, and I've never heard of any specific safety or environmental concerns about either epoxy or vinylester when cured in a composite matrix, other than the general environmental concerns that pertain to all petroleum/plastic products such as disposal.
 
I thought I was told epoxy had more worker protection issues than vinylester, and thus why US manufactures mostly seem to use it, while at least some Canadian use epoxy still. Maybe all about cost. I do read consistently that epoxy adheres to wood much better than vinyl ester and may be a little stronger. It seems more pleasant for the DIY user to use. Epoxy is quite sensitive to UV; is vinylester better?
 
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