I had posted some information on a forum a few years back about whether Rhododendron wood was safe for making utensils. I got varied opinions, but along the way I did more research that may shed some light on this issue.
When my wife and I moved to WV, we noticed that there were rhododendrons everywhere. The wood from the plant is dense and seems as if it would be good for carving utensils from it. In fact, I believe some people call it Spoonwood around this area. This got me to thinking that since they grow everywhere like weeds, they would make a good source of wood that could be harvested without impact to the forests.
However, Rhododendron has a reputation for being poisonous and therefore seems that further investigation was necessary to determine whether one could use the wood from this plant or if it should be avoided. The only official study that I was able to find was one conducted by the School of Agricultural and Forest Sciences at the University of Wales, Bangor.
http://www.wildresources.co.uk/reports/rhodo_eng.pdf
This study shows the levels of grayanotoxin in the different parts of the plant. The grayanotoxin is the neurotoxin that is responsible for illness or death in animals and humans. It shows that the highest concentration is in the flowers and leaves and if ingested in moderate quantities can be fatal. There are two main grayanotoxins covered in the study, GI and GIII. These were the subject of the study as they are the most toxic while the others would pose less of a significance over these two.
The level of GI found in the flowers is 55.26mg/g while the amount found in green wood is just .3042mg/g. The toxic level of ingestion is 5526mg to 12,433.5mg of grayanotoxin-I to seriously poison a 55lb(25kg) child. This would indicate that the toxic dose in an averaged sized adult (165lb) would be from 16,758mg to 37,300.5mg. To get to these levels of toxicity, one would have to physically ingest up to 122,618.34mg or 122.6 grams of wood. This is 4.3 ounces of actual wood that would have to be ingested to consume enough GI to be toxic.
Since one is not consuming the wood we can infer that the actual amount of GI exposure to the green wood is fairly low. The grayanotoxins were not shown to pose a risk for absorption through the skin which would lead me to believe that handling the wood is safe. So carving the wood should pose no significant risk of exposure to grayanotoxin.
Consequently the level of GI drops to less than half, or .1341mg/g in dry wood. This level can also be further reduced by washing the dried wood as the grayanotoxins are water-soluble. At this concentration there would be not even be enough GI in the dried wood to cause any symptoms.
So we can determine that in a spoon carved from Rhododendron that weights 1 ounce when dried, would only contain 3.8mg of GI embedded in the wood. This is 1454 times less than the toxic dose of greyanotoxin-I by ingestion. Again, unless you are physically eating your spoon, the amount you would consume from using such a spoon would be significantly lower.
So does this mean that it is safe to use Rhododendron wood for making eating utensils? Well I have come to my conclusion, but I will let you make that decision on your own.
Dave
Lawyer Note: The above should be taken as an analysis of a study conducted by the University or Wales and not to be used as a definitive resource for basing ones decision for the safety of using Rhododendron wood for eating utensils or for the safety of handling any part of this plant. By using the Rhododendron plant you assume all responsibly for the consequence of such an action which could result in illness or death.
I can’t imagine why anyone would want to risk using a spoon made from a plant known to contain a neurotoxin when there are plenty of excellent species of wood available for use that are known to be safe…
Even life itself is so dangerous itself that you can die from it.
Dave,
Thank you for the interesting post. However, I think some of your calculations are off – in the fifth paragraph.
If there are .3042 mg of GI in one gram of green wood, it would take 16758/.3042 = 55,089 grams of green wood to get the 16,758 mg minimum average adult toxic dose. This is 55 kg (121 lbs.) of green wood.
For dried wood, the figure is 275 lbs. of wood for an average adult, and 91 lbs. for an average child to reach the minimum toxic dose. This is equivalent to 4400, and 1456, one-ounce spoons, respectively.
So, if an adult ate one of your spoons every day for 12 years and fully retained all of the poison in his body, it could be rough going.
Thanks for the interesting blog.
Rob
Thanks for your analysis. Will take it in consideration! Have thought of using this plant before. Rhododendron is more rare in my area. But love to carve a spoon with it (not persé a spoon to use).
Best regards,
Maarten
I got some Rhododendron a couple of weeks ago. Although it was not freshly cut, it was still quite green. I did the diligence as far as toxicity. Nothing to worry about there as I am sure no one is going to actually eat the wood itself. Splitting the wood into usable billets is the real deterant. I usually use a maul and fro to work stuff up. No joy with rhod. I even tried an 8 pound steel splitting maul and it just bounced off. I did manage to turn some (on a spring pole lathe) and it worked quite as well as I expected. NIce texture and color. Not sure what I will do with the rest of what I have.
The biggest problem I found with Rhododendron is getting it to split. A maul and fro is useless and an 8 pound splitting maul just bounces off. All this was after I found out how actually low the toxicity is in the wood as opposed to the leaves and flowers.
Ended up giving the rest of the Rhod. to a blacksmith who makes his own charcoal. This is supposed to make very good charcoal for tool making.
OK, this is off topic but I cut a couple dead branches off and it had dried up pods on it. My dog grabbed the branch and was biting it and the pods. Based on the above is it toxic for her. She was chewing on the end I cut off. She is 77 pounds.
Hey Annette,
I am not a vet so I can’t give you any definite advice, but I do not think that chewing on a dried branch will do anything. However if you are concerned enough I would recommend you see a vet. I would hate for something to happen to your dog, so you might be better off taking her to the vet just in case.
Hi.
Nice article, I read the study and came to much the same conclusions.
Considering that all things are potentially toxic or poisonous in the right dose, I think we as humans analyse insignificants far too much, that’s not to say we should not use understanding (sometimes known as knowledge). To get the real answer to all our questions would be to be able to ask the indigenous peoples from where it originated (Himalayas and south-eastern Tibet), because you can bet your hind teeth they would know what it can be used for, its herbal properties and some mystical folk law too.
I have just started looking at using rhododendron as we in the UK are plagued with the stuff; it causes increased soil acidity and shades out all other woodland plants. I have figured that if it can be turned into products then it might solve the requirement for volunteers to go rhody bashing to try and reduce its impact.
One last thought ….We nearly all drive cars, live in towns and eat highly processed food which I would consider far more dangerous than a little wood smoke especially if your wood is dry and well seasoned (hardly no smoke at all) How many people have died or been admitted to hospital with rhododendron poisoning?
Thank you. Very interesting.
This thread, the University of Wales study and the article above are the only references I’ve managed to find on the internet on the subject. I cant even find a fact sheet or tool-box talk on the Forestry Commission website, although a woodsman I know tells me they are ‘no longer allowed’ to burn the brash from the plant due to carcinogens. All woodsmoke is toxic – not least from CO, is it not?
I am managing a Community project that aims to turn invasive and roadside ponticum into woodfuel, kindling and charcoal and need to be able to assure the community it is safe to use – as I believe it to be. Has anybody found any more info?
Best wishes,
Sara
Does rhoderdendron have a colourful grain similar to yew and is it used for turning?
It is more of a consistent blond color. It is a fairly dense wood but carves really nice when green. I have not turned it but it seems like it would work fine if you found a large enough piece.