# How poisonous is the Upas tree? **URL:** \ **Category:** Factual Questions\ **Created:** [September 15, 2016, 3:27pm UTC](https://boards.straightdope.com/t/how-poisonous-is-the-upas-tree/766007 "2016-09-15T15:27:34Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Love\_Rhombus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/love_rhombus/32/10694_2.png) [@Love\_Rhombus](https://boards.straightdope.com/u/Love_Rhombus)\ **Post date:** [September 15, 2016, 3:27pm UTC](https://boards.straightdope.com/t/how-poisonous-is-the-upas-tree/766007/1 "2016-09-15T15:27:34Z")
I know it’s said to be incredibly deadly, but on the range of poisonous plants, where does it fall? And how dangerous is it to encounter in nature? ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [September 15, 2016, 5:45pm UTC](https://boards.straightdope.com/t/how-poisonous-is-the-upas-tree/766007/2 "2016-09-15T17:45:46Z")
> [@Love\_Rhombus](#): > > I know it’s said to be incredibly deadly, but on the range of poisonous plants, where does it fall? And how dangerous is it to encounter in nature? The sap is quite poisonous. If you got some in a cut or your eyes, you could be in trouble, it is used for making poison. However, it’s fruit is edible and the bark, roots, etc all have uses. The tree is a common shade tree. There’s are some “travelers tales” which greatly exaggerate the deadliness of the tree. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [September 15, 2016, 5:46pm UTC](https://boards.straightdope.com/t/how-poisonous-is-the-upas-tree/766007/3 "2016-09-15T17:46:47Z")
> [@Love\_Rhombus](#): > > how dangerous is it to encounter in nature? Not dangerous, apparently. [Wiki says](https://en.wikipedia.org/wiki/Antiaris): > [@](#): > > Antiaris toxicaria is an excellent, fast-growing shade tree and often is grown around human dwellings for shade. The leaf litter is an excellent compost material and high in nutrients. It often is applied as mulch or green manure in local gardens … > > The fruit is edible, and birds, bats and humans that eat it spread the seeds. The toxin - which is not to be trifled with - is in the sap (aka latex). ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [September 16, 2016, 5:27am UTC](https://boards.straightdope.com/t/how-poisonous-is-the-upas-tree/766007/4 "2016-09-16T05:27:54Z")
The sap has an LD50 (lethal dose for 50%) of 0.10 mg per kg of body weight. That’s quite poisonous. For comparison, curare was also used on arrows, it has an LD50 of 0.735. Strychnine has an LD50 of 1.0 to 2.0 in humans. King cobra venom is almost as toxic, with an LD50 of 0.125. So that’s a pretty toxic substance. ---
**Author:** ![RainPops](https://avatars.discourse-cdn.com/v4/letter/r/9dc877/32.png) [@RainPops](https://boards.straightdope.com/u/RainPops)\ **Post date:** [September 16, 2016, 6:46am UTC](https://boards.straightdope.com/t/how-poisonous-is-the-upas-tree/766007/5 "2016-09-16T06:46:04Z")
hi Its not poisonous! Its referred more accurately; I believe within a medical perspective; of course anyone may say that Im wrong; by the na-me of dangerous; its a dangerous tree because it can catch up to the veins which are connected to the nervous system; it is medically referred to by the name of a neurological danger . ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [September 16, 2016, 12:34pm UTC](https://boards.straightdope.com/t/how-poisonous-is-the-upas-tree/766007/6 "2016-09-16T12:34:23Z")
> [@RainPops](#): > > hi Its not poisonous! Its referred more accurately; I believe within a medical perspective; of course anyone may say that Im wrong; by the na-me of dangerous; its a dangerous tree because it can catch up to the veins which are connected to the nervous system; it is medically referred to by the name of a neurological danger . I wouldn’t snort it either. :dubious: ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [September 16, 2016, 12:40pm UTC](https://boards.straightdope.com/t/how-poisonous-is-the-upas-tree/766007/7 "2016-09-16T12:40:51Z")
> [@RainPops](#): > > hi Its not poisonous! Its referred more accurately; I believe within a medical perspective; of course anyone may say that Im wrong; by the na-me of dangerous; its a dangerous tree because it can catch up to the veins which are connected to the nervous system; it is medically referred to by the name of a neurological danger . Reported. ---
**Author:** ![Malthus](https://avatars.discourse-cdn.com/v4/letter/m/85f322/32.png) [@Malthus](https://boards.straightdope.com/u/Malthus)\ **Post date:** [September 16, 2016, 2:00pm UTC](https://boards.straightdope.com/t/how-poisonous-is-the-upas-tree/766007/8 "2016-09-16T14:00:51Z")
> [@t-bonham@scc.net](#): > > The sap has an LD50 (lethal dose for 50%) of 0.10 mg per kg of body weight. That’s quite poisonous. > > For comparison, curare was also used on arrows, it has an LD50 of 0.735. > Strychnine has an LD50 of 1.0 to 2.0 in humans. > King cobra venom is almost as toxic, with an LD50 of 0.125. > > So that’s a pretty toxic substance. Question: does its toxicity require that it be injected into the bloodstream (for example, with an arrow)? Or is it also toxic if ingested? ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [September 16, 2016, 2:21pm UTC](https://boards.straightdope.com/t/how-poisonous-is-the-upas-tree/766007/9 "2016-09-16T14:21:49Z")
> [@Malthus](#): > > Question: does its toxicity require that it be injected into the bloodstream (for example, with an arrow)? Or is it also toxic if ingested? Or as a suppository? It is the Upas tree after all. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [September 16, 2016, 3:54pm UTC](https://boards.straightdope.com/t/how-poisonous-is-the-upas-tree/766007/10 "2016-09-16T15:54:59Z")
> [@t-bonham@scc.net](#): > > The sap has an LD50 (lethal dose for 50%) of 0.10 mg per kg of body weight. That’s quite poisonous. I think that’s the LD50 of pure [antiarin](https://en.wikipedia.org/wiki/Antiarin), which is the poisonous compound in the sap. [This article](http://www.thefreelibrary.com/Blowpipe+dart+poison+in+Borneo+and+the+secret+of+its+production%3a+the...-a0166350047) says that “1.5 to 2 percentage of the total weight of the original latex consists of [beta-Antinin].” So the LD50 translates to 5mg of sap per kg of body weight. Still a scary number - it implies 1/10 teaspoon of the sap can kill a person. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [September 16, 2016, 4:20pm UTC](https://boards.straightdope.com/t/how-poisonous-is-the-upas-tree/766007/11 "2016-09-16T16:20:02Z")
> [@Malthus](#): > > Question: does its toxicity require that it be injected into the bloodstream (for example, with an arrow)? Or is it also toxic if ingested? Well the fruit is edible. And it is possible that the sap is only dangerous thru the bloodstream, but betting on that is never safe, due to small sore or cuts in the mouth or ulcers. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [September 16, 2016, 7:20pm UTC](https://boards.straightdope.com/t/how-poisonous-is-the-upas-tree/766007/12 "2016-09-16T19:20:34Z")
That Wikipedia article says that the wood has some uses. Umm, how do the people logging and milling the wood avoid getting in contact with the sap? Chainsaws, etc. are going to throw that stuff all over the place. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [September 16, 2016, 7:30pm UTC](https://boards.straightdope.com/t/how-poisonous-is-the-upas-tree/766007/13 "2016-09-16T19:30:57Z")
> [@ftg](#): > > That Wikipedia article says that the wood has some uses. > > Umm, how do the people logging and milling the wood avoid getting in contact with the sap? Chainsaws, etc. are going to throw that stuff all over the place. I wondered about that myself. 😕