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.
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.
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.