I was all prepped to update this post, but it turns out nothing has really changed. People still think that poinsettias are poisonous and sources that are seen as authorities in social media continue to propulgate the myth. But poinsettias are not poisonous. I added one additional reference at the start and left the original post in its entirety below.
Krenzelok, Jacobsen, and Aronis (1996), in an article title”Poinsettia exposures have good outcVreeman & Carroll, 2008omes… just as a thought,” analyzed plant exposures reported to the American Association of Poison Control Centers. Poisettia accounted for almost 23,000 cases with zero fatalities, less than 4% going for treatment at a healthcare facility, and more than 92% not developing any signs of illness.
My personal favourite was an article from the British Medical Journal, The BMJ, that busted several holiday/cold weather myths including this one. I will share some of the other myths over the next few days via twitter and instagram, both of which you can find links to on the main page. They mainly used the study above as their source, but also cited one on rats that could not identify toxic levels even at 500-600 leaves or nearly a kilogram of sap (Stone & Collins as cited by Vreeman & Carroll, 2008). What I want to know is how did a rate at a kilogram of anything? Perhaps there is a future post in that question.
Original Post (January 2016)
A few years ago someone gave me a huge poinsettia at work. When Christmas holidays arrived I was pretty concerned. I have a cat at home and I had heard that poinsettias were incredibly poisonous. I considered leaving the plant at work, where it would most likely die while the office was closed. But being me, I chose to do some research first.
Turns out poinsettias have a bad rap. Chances are you would have to consume a lot of poinsettia to feel any ill effects. At that goes for animals as well. If any, signs of poisoning might include mild vomiting, drooling, or even more unlikely diarrhea. The milky sap may cause skin irritation, and eye exposure could cause some inflammation. (Pet Poison Helpline)
So just how mild? According to POISINDEX (R) a 50-pound child would have to eat more than 500 leaves to consume enough that it would be toxic. So, even my tiny little cat would have to eat several complete plants before she experienced any ill effects.
So how do these myths get started? So often, myths like these get started by attributing blame without knowing the actual cause or causes. Supposedly the poinsettia myth started in 1919 when a two-year-old supposedly died from consuming a poinsettia leaf (read about it here). Despite later findings regarding the actual cause of death, the myth had begun.
The problem is that sometimes these myths seem to make a lot of sense. When you hear that a vaccine works by introducing a similar virus (etc) into the body, it is easy to make the leap that the vaccines will make me sick. When you hear that compact fluorescent lightbulbs (CFLs) contain small amounts of mercury it is easy to consider them unsafe for the house. But a little extra time, will often reveal these to be stories, rather than facts. Check out my post on vaccines for more info. And a CFL contains about one hundredth of the mercury content of older thermostats. And based on the release rates, a broken bulb would need to be left in a room for several weeks before the mercury vapour in the room reach levels that would be hazardous to a child. Get more information here.