Mike, the article you've is certainly correct in listing some of the hazards but severely overstates the dangers.
You can continue to use isopropanol as you've been doing with absolutely no ill effects. Obviously you want to avoid inhaling the spray, but it is not a health hazard unless you inhale large quantities of spray or are chronically exposed to the fumes.

I've linked the material safety data sheet here.

Here is a link that might be useful: Isopropyl alcohol MSDS

Thanks Rennett, I should have looked up the MSDS for the full effects of exposure. I think the site I linked to was speaking in terms of intentional inhalation which is often called huffing. I do get a headache if I inhale the vapor but I try to spray a plant in the bath tub and then let it drip dry all while having the bathroom window open for air flow. I have a lot of Hoyas so when I spray the plants every two weeks I go through a bottle or two of IPA and I was beginning to become concerned about any possible effects.
It's quite amazing how mealies are attracted to my Hoyas and Stapeliads but I rarely ever see them on my orchids or other plants.

Mike

Yup, your concerns are certainly valid. I just wanted to let you know that you shouldn't be in any danger unless you inhale a ton of the stuff or are exposed for hours at a time.

Good luck killing off those mealies.
I was lucky enough to have caught an infestation early, and managed to exterminate all of them in a couple rounds of treatment with isopropanol. I haven't had any mealies since August, so I hope it stays that way.

I personally don't think you're unduly concerned, Mike. And I don't find Rennet's link that much more comforting as it suggests "repeated exposure" as leading to organ damage as well as "prolonged exposure." Given that under the best of circumstances, the conclusions one can draw from such research are inexact, I think it's fair to say that we aren't certain how injurious long term use by a serious hobbyist like Mike (or any of us) would be.

I always think, if I am experiencing headaches or dizziness, maybe I should not be so quick to reassure myself that it's "all in a day's use of household chemicals." I believe we too frequently convince ourselves it's all a bunch fuss over nothing in order to give ourselves permission to keep using products that are convenient in ways that are convenient instead of erring on the side of caution.

Hope I don't sound too neurotic. ^_^;
This whole conversation reminds me of that guy who got popcorn lung from his popcorn addiction.

Here is a link that might be useful: Popcorn lung

LOL I did hear about that popcorn lung incident, that guy was a popcorn fiend.

I am going to continue using IPA but I am also much more aware of the effects and warning signs of exposure. I think I will switch back to Neem for the winter so I don't have to run around opening all the windows.
GG you are very right about household cleaners. I work with chemicals every day at work and some of the household cleaners or cleaners commonly used by people who never get to see a MSDS sheet are truly bad for your health. A friend used to wash his hands with a fairly common product to remove grease when he worked at a garage. I showed that same friend the MSDS sheet and he was shocked, it causes blood cell abnormalities among other toxic effects.

Mike

@greedyghost
MSDS will list any potential effects of the material in question, and it can be difficult to put them in context.

For vapourized isopropanol (U.S. values):
TWA: 980mg/m3
STEL: 1225mg/m3

TWA means that an average person can be exposed to a concentration of 980mg isopropanol per square meter over an 8 hour workday with no ill effect.

STEL is the concentration a person can be exposed to for a 60 minute period with no ill effects.

Both of these values are conservative and well below ceiling values. They're meant for workplace safety for people who work with or are exposed to the chemicals regularly.