Does anyone know exactly why Florel has a 48 hr REI?
A lot of chemicals have to do with contact safety. I think florel is one that is dangerous for eye contact. Some chemicals the companies can't afford to get a new label.
This should help you with your REI issues.
Some chemicals, even after appearing to have dried, can still emit vapors that can be some what irritating or toxic. My impression is that companies occassionally go overboard on REI recommendations in order to avoid law suits.
I've often wondered the same thing. I've fired off an e-mail to Joyce Latimer to see if she can offer any insight. I can't think of another chemical we use in the nursery that has a 48 hour REI. We only use those with a 24 hour REI when there's no alternative. 12hr or less is our standard.
Paul- we are the same way. A 24 hr REI is tough enough. Another person to ask might be Peter Konjoian. Hasn't he done a lot of work with Florel?
Florel is one of the cheapest pgr's in the market. I'll gladly keep the 48 hr REI to keep the price where it is.;)
Carole, here's what Joyce said (sorry for the delay):
"For ethephon, I remembered Peter Konjoian talking about this, about it having to do with acidic nature of the product. So, I went looking and found the info below from the 1995 EPA re-registration documents for ethephon (Florel, Rhone Poulenc):
'A 48 hour restricted-entry interval (REI), as imposed by the Worker Protection Standard (WPS), will be retained based on potential eye and skin irritation concerns. The Agency has determined that this 48-hour REI must be increased to 72 hours when ethephon is applied outdoors in arid areas. In addition, since ethephon is classified as toxicity category for eye irritation potential, protective eyewear is now required. http://www.epa.gov/oppsrrd1/REDs/0382.pdf'"