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  1. #46
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    Quote Originally Posted by renateochse View Post
    Hi Rob
    I know this is an old post- we took down a eucalyptus tree in New Zealand end of Sept 2106. it was cut up in our yard and large logs removed. We pulched the remainder for the garden. There was a heap of saw dust lying around from the sawing which I distributed onto the flour beds in quite windy conditions. Since then I have struggled with hives, itches skin rashes that are not just contact dermatitis but spring up anywhere they choose. Have had a dry cough for weeks now which before was more just a feeling like I had swallowed dust. Nothing seems to help - went on prednisone - off that now and onto a detox regime....any ideas??
    I have a similar reaction to this but only to selected species and particularly to NSW scented rosewood. FOR ME, exposure to scented rosewood fires up my underlying asthma and causes a rash anywhere my clothes may rub against me such as collars and sleeve entries. I also find that the clothes that I am wearing need to be washed or another attack will occur just from putting the same clothes back on! However, I don't have an adverse reaction to common eucalypts? Do you have a picture of the tree to help identify the species?
    fletty
    a rock is an obsolete tool ......... until you don’t have a hammer!

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  3. #47
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    Default Ironwood Erythrophleum chlorostachys, beautiful wood, is it safe as a chopping board?

    Hi all, I live up in the NT and have some iron wood. I have heard it has some toxic properties as its used as traditional medicine and the leaves are toxic to animals. It's extremely hard, heavy and durable and it would look fantastic as a chopping board.
    Would anyone have advice if this could be used as a chopping board? I can't find any info on it?
    Many thanks for your advice!

  4. #48
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    Quote Originally Posted by Mace and Olga View Post
    Hi all, I live up in the NT and have some iron wood. I have heard it has some toxic properties as its used as traditional medicine and the leaves are toxic to animals. It's extremely hard, heavy and durable and it would look fantastic as a chopping board.
    Would anyone have advice if this could be used as a chopping board? I can't find any info on it?
    Many thanks for your advice!
    It would be fine for a chopping board. The outside of the tree is nasty and you need to be careful making the chopping board, many people have allergic reactions to it, but once dry and finished the heartwood is fine. It is the same species as Cooktown Ironwood
    Neil
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  5. #49
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    The usual timber references do not give any information about toxicity for this timber but John Brock in 1988 claimed that all parts of the tree are highly poisonous to mammals Ref.: Brock, J. (1988). Top End Native Plants. (John Brock: Darwin). Many species in this pea family are renowned for their toxic affect on people (e.g. Yellow Sirus, Red Sirus, Blackbean)

    Most evidence of stock poisoning is from ingesting the leaves, so it may be ok as dai sensei says in post #48 above. However, human reactions to timber can be very different person-to-person so, knowing that the plant contains some very toxic chemicals and that they must be present in some concentration in the timber I would advise against using the timber for any food-contact items. You might get away with it, but how would you feel if someone was sensitive and had a reaction. Ingesting ironwood leaves can kill a buffalo ... the toxicity level is high.

    David
    Last edited by Xanthorrhoeas; 5th March 2017 at 03:13 PM. Reason: typo

  6. #50
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    I hear a lot about people using Ironwood for this and that and shake my head. Its a nice timber. And it will kill you.
    I've got war spears from the cape. Typical spear, with a splinter of ironwood on the end thats held there with beeswax and twine. If the spear gets ya, the splinter will detach and a splinters all it takes.
    Mate of mine got an ironwood splinter in his foot walking around in an old dam (stood on top of a snapped off fencepost. Three days later we airlifted him out to Kathrine hospital, dammed near killed him.
    Usual stories about cows eating leaves etc etc are all true, and the one about not cooking with it because it'll taint your steak is true too.
    I had a pup chewed a doorstop I had. The operative word being had.

    Google sodium fluroacetate - thats the active compound found in Ironwood. Might as well lick a 1080 bait as make a breadboard from ironwood ifn you ask me. Y'ever heard a baited dog howling? Dont sound like a nice way to go to me. Course thats just me, and people make stuff from it all the time.

    Me, I got ironwood in furniture. I dont put my food on the furniture. And I'll allow that any form of surface coating means the timber isnt in food contact anyway. But still we got some ugly nurses in these hospitals. I dun wanna go there...

  7. #51
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    Interestingly the OHS air exposure limit for PURE Sodium fluoroacetate is 0.05 mg/m^3 - but hang on that's only 20X more than plain old hardwood sawdust (1 mg/m^2) and 10 times more than MDF.

    BTW The hardwood OHS limit is based on English oak!

    So what does this say about the toxicity of sodium fluoroacetate or the toxicity of plain old hardwood sawdust.

    I don't doubt the toxicity of the
    Sodium fluoroacetate but what is does indicate is we need to treating all sawdust way more seriously.

    And what would be the toxicity level for Cooktown ironwood sawdust?

    See that's the thing is no one has really done a proper investigation into Australian species toxicity.

  8. #52
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    Default Toxicity studies needed, some science and a rave

    Yes, BobL, I agree. For instance an internet search for toxicity for Cooktown Ironwood produced nothing for me, and the IWCS 2006 report has zilch too. My post above was based upon caution being better than disaster. JohnG obviously has some much better source of information, and thank goodness he does and has shared it, as it may help avoid a disaster.

    As a scientist one of the thought processes when considering a question/unknown is always to go back to first principles. As woodworkers we enjoy working with wood, love wood. But, consider what wood is - first principles. It is the old, no longer living parts of the plant where the plant stores its chemical waste products. The tree depends upon this old tissue for support to keep its leaves where they can be in the sunlight, so there is a biological/genetic advantage to having the wood intact/uneaten/strong. In general terms (of course there are exceptions, mostly those plants bred by humans for consumption) plants are in a never ending war with the animals and fungi that eat/attack/rot them. It is a biochemical war where, over evolutionary time, the plants develop ever more sophisticated poisons to protect themselves. Some of those poisons are stored in the wood to protect it. So ... wood is intrinsically dangerous because it contains dangerous chemicals, and wood dust contains those chemicals as well as being a physical size that can damage our lungs and respiratory tissues.

    As woodworkers we can love love wood, but we should understand it and treat it with the respect it deserves.

    Pure science in Australia is just about dead. Short-sighted economic-rationalist governments and politicians do not understand that you need a lot of pure research to fuel the applied research that creates economic wealth and employment. Once CSIRO was a world leader in research now they have a highly paid chief exec, a big bureaucracy and very little research. They still cost a lot to run. Universities employ primarily on contract so the employees don't get paid in the holidays - not much chance of pure research from them if they are starving.

    David

  9. #53
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    Good post David.

    Everything is toxic its just the dose that varies.

    This has been posted before but even good old eucalyptus oil is toxic.
    As little as 3.5g (~100 drops) administered orally has lead to fatalities in children yet it continues to be used in all manner of products including medicines.
    Dry eucalyptus leaves contain as much as 10% oil and about half that is what is specifically known as "eucalyptus oil" so 70g of dry leaf contains enough for a lethal dose.

    BTW the CSIRO book on Forrest trees of Australia lists ALL parts of the Cooktown Ironwood Tree as HIGHLY poisonous in the first paragraph of its 2 page entry.
    I would be really interested to know the concentration of sodium fluoroacetate in the wood.

  10. #54
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    Thanks Bob, That is another reference book I didn't have. I must have been asleep when the CSIRO list came out in 2006! It is now winging its way to me from CSIRO.
    David

  11. #55
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    Quote Originally Posted by Xanthorrhoeas View Post
    Thanks Bob, That is another reference book I didn't have. I must have been asleep when the CSIRO list came out in 2006! It is now winging its way to me from CSIRO.
    David
    It's an excellent book, even just to sit and read.

  12. #56
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    Each up to their own, but personally I think the poisonous features of the actual timber has been exaggerated due to ignorance. Certainly the leaves, sap and bark are an issue, but the heartwood would have SFA poison and it has been used on boards for years because it lasts so long. The aboriginals have used various parts of the tree for medicine and indeed I believe someone is looking into it as a cure to cancer. It is also a favourite tree for native honey bees in the NT. As for spears, it wasn't the splinters you had t worry about, it was the hard sharp pointy bit.

    The sawdust would be a problem, but so is the sawdust from all trees. Splinters are also a real problem but not necessarily due to any poison in the wood. My understanding is that it is due to them not dissolving or causing infection like normal splinters, so they can travel through the bloodstream, then getting caught.

    I guess I see it similar to camphor laurel, considered a poisonous tree which it is, but you'd need to eat a tree of timber before you even get sick. In some countries they drink a small glass full of camphor oil every day, and also, it does make the best cutting boards because of the antibacterial properties.

    Yeh I know, CL is different, I'm just saying lack of knowledge is always an issue. Yes a study would be good, but again look at CL, there have been many a study and there are still many people on both sides of the fence.
    Neil
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  13. #57
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    There's a lot of poisonous plant compounds out there, and a lot of poisons What makes sodium floroacetate stand out is that it isn't like an insecticidal poison where exposure might be an irritant to everything else. Rather it is a mammalian poison, and a very effective one.

    So let's look at this from another viewpoint. Chromium in trace amounts is required as part of a human diet. Copper in trace amounts is necessary also. Arsenic in trace amounts is actually a mammalian growth stimulant. Put them on timber as an insecticidal treatment in the form of CCA and it's a good bug deterrent that's quite human friendly.
    And empiracly, you'd be safer using unsealed CCA treated timber for food prep then cooktown ironwood. There's no part of sodium floroacetate that's good for mammals.

    100 grams of leaf will kill a cow or camel that weighs 3/4 a ton .
    2 leaves will kill a sheep.
    If a dog licks a tyre that's driven over a 1080 bait it's pretty much dead dog.
    A splinter in a horse is enough to cause Ironwood poisoning. If not removed promptly: dead horse.

    im not saying Cooktown Ironwood shouldn't be used. It's a good timber.

    But I would suggest it be handled with great care with regard dust exposure, food contact, and splinters because its proven lethal to humans and there isn't any cure.

  14. #58
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    OK I have some back of the envelop numbers we can look at.

    Lethal dose for FCH2CO2Na is between 2 and 10 mg/kg of body weight. Lets use the lowest dose i.e. 2mg/kg

    Lets deal with a 20 kg child, this means 40 mg of FCH2CO2Na is needed. This is just over one drop of the stuff so not much.

    Finding the concentration of FCH2CO2Na in plants proved rather tricky but I eventually found some data here http://www.ecotox.org.au/aje/archives/vol3p57.pdf

    Seeds seem to have the greatest concentrations of FCH2CO2Na, followed by fresh leaves.
    There is no information for wood but it should be significantly less than both of these.
    I cannot find the concentration of FCH2CO2Na in Cooktown ironwood but the greatest naturally occurring concentration ever measure in a plant is 8g/kg in a south African plants seeds.

    For Australian plants the typical concentration is 2.6 g/kg in leaves.

    So to get 40 mg of FCH2CO2Na you will need 0.04/2.6 kg = 15 g of leaves.

    Wood should have lower concentrations than leaves but lets assume they are the same.

    One toothpick = 0.14g so a child would have to eat 15/.14 = 107 toothpicks of wood to die.
    A 100 kg person would have to eat 535 tooth picks.

    So I can understand getting sick but unless they are allergic to it I cannot understand death in a human from eating the wood.

    The 50% lethal dose for carnivores like dogs is 30x lower than for humans so 50% of 20kg dogs who ate 4 toothpicks of ironwood would die. A 5kg pup would only need to eat 1 tooth pick worth.

    FCH2CO2Na also is present in tea leaves in relatively high concentrations but there's something about tea that holds the FCH2CO2Na in the leaf and does not extract much and you would have to drink 875 cups of tea to reach a lethal dose.

    At 250 ml of water per cup you would die from consuming too much water before you reached the FCH2CO2Na limit and the caffeine dose would also be serious.

  15. #59
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    Nice analysis Bob, and I really like the toothpick analogy.

    By the same analysis you'd need to consume 18,754 treated toothpicks to get a lethal dose of CCA.
    Everything is relative.

  16. #60
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    Quote Originally Posted by John.G View Post
    Nice analysis Bob, and I really like the toothpick analogy.

    By the same analysis you'd need to consume 18,754 treated toothpicks to get a lethal dose of CCA.
    Everything is relative.

    Cheers John,

    Have some feeling for the pup chewing wood.
    One of our border collies completely ate / chewed off the front half off both the rockers on a family heirloom english oak rocking chair, while the other BC took multiple chews out of the 8 new tassie oak dining room chair rungs.

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